Importancia biológica de los telómeros / Biological importance of telomeres

Se exponen los hallazgos históricos y la importancia biológica de los telómeros en la vida celular y en los aspectos genéticos del ADN humano. (AU)

The discovery and the biological importance of the telomeres are exposed. (AU)

Prenatal diagnosis of a rare case of complete ring chromosome 15 / 中华围产医学杂志

This article reported a prenatally diagnosed case of complete ring chromosome 15. A 38-year-old woman who conceived by in vitro fertilization and frozen embryo transfer underwent amniocentesis for prenatal diagnosis at 18 +5 weeks of gestation due to advanced maternal age. The result of G-banding karyotyping was mos 46,XX,r(15)[88]/45,X,-15[11]/46,XX,r(15;15)[1]. No numerical abnormalities of chromosomes or definite pathogenic copy number variations (CNVs) were detected by chromosomal microarray analysis. Amniocentesis was performed again at 31 +6 weeks of gestation. The result of genome copy number variation sequencing indicated no pathogenic CNV and fluorescence in situ hybridization on cultured amniocytes revealed nuc ish(15q)×1[15]/(15q)×3[5]/(15q)×2[80]. Based on all the prenatal diagnosis results, it was suggested that the fetus carried a complete ring chromosome 15. As the peripheral blood chromosomes of the couple were normal and no obvious abnormalities were detected by the prenatal ultrasound either in our hospital or another hospital, the pregnant woman decided to continue the pregnancy after genetic counseling and delivered a baby girl at 41 weeks of gestation. The girl showed no physical abnormalities during a seven-month follow-up.

Prenatal diagnosis of a fetus with mosaic trisomy 2 and uniparental disomy of chromosome 2 / 中华围产医学杂志

This paper presented the prenatal genetic analysis of a case of mosaic trisomy 2 combined with uniparental disomy 2. The pregnant women underwent non-invasive prenatal testing in Zhuhai Center for Maternal and Child Health Care on February 2019, which indicated an increased number of chromosome 2. Subsequently, amniocentesis was performed at 21 +2 weeks for prenatal diagnosis. No abnormalities were detected through the karyotype analysis of amniotic fluid cells. Chromosome microarray analysis of uncultured amniotic fluid cells revealed a duplication of 2.3 copies in chromosome 2 and 64.3 Mb regions of homozygosity in the 2q21.2q33.1 region. The comparison of single nucleotide information on fetus-parent chromosome 2 showed that the regions of homozygosity of the fetal 2q21.2q33.1 was paternal uniparental isodisomy (2), with the rest of chromosome 2 being paternal uniparental heterodisomy (2).Ultrasound results at 27 +6, 31 +6, and 34 +5 weeks of gestation showed continued exacerbation of fetal growth retardation with placental abnormalities and fetal blood flow spectrum abnormalities. Due to threatened preterm delivery at 35 +3 weeks, The pregnant woman chose to give up the fetus and delivered a stillbirth.

Chromosomal karyotype analysis of peripheral blood in infertility patients with different semen quality / 中国现代医生

@#Objective To analyze the type and incidence of abnormal chromosome karyotype in peripheral blood of infertile patients with different semen quality.Methods Selectet 292 infertility patients who came to our hospital from January 2018 to December 2021 for G-banding karyotyping and semen analysis.According to the semen analysis results,the patients were divided into abnormal semen quality group and normal control group.We made statistics and analysis on the abnormal karyotypes.Results In the group with abnormal semen quality,20 cases(18.87%)of abnormal karyotypes were found.In the normal control group,9 cases(4.84%)had abnormal karyotypes were found.The comparison of the abnormal rates of peripheral blood chromosome karyotypes between the two groups showed statistical significance(P<0.05).The detection rate of chromosomal abnormalities in patients with Azoospermia was 50%,and sex chromosome abnormalities were the main types of abnormalities in this group.Conclusion Karyotype analysis of infertile patients can effectively analyze the causes of infertility,and has important clinical significance for assisted reproduction and primary prevention of birth defects.

Ultrasonic manifestations and genetic abnormalities in the second trimester of pregnancy of fetal congenital kidney anomalies / 中国医学影像技术

Objective To observe the ultrasonic manifestations and genetic abnormalities in the second trimester of pregnancy of fetal congenital kidney anomalies(CKA).Methods Totally 14 singleton pregnancy women with CKA fetus detected with prenatal ultrasound and proved by genetic examination who underwent prenatal ultrasound in the second trimester of pregnancy were enrolled.The ultrasonic manifestations and genetic abnormalities in the second trimester of pregnancy were observed.Results Among 14 fetuses,simple renal abnormalities were detected in 10,while renal abnormalities complicated with extrarenal abnormalities were noticed in 4 fetuses with prenatal ultrasound in the second trimester of pregnancy,presented as enhanced renal echoes,renal pelvis separation and ectopic kidney,etc.Genetic examination showed chromosomal karyotype abnormalities in 4 fetuses,chromosomal copy number abnormalities in 8 fetuses,and genetic mutations in 2 fetuses.Conclusion The ultrasonic manifestations in the second trimester of pregnancy of fetal CKA included enhanced renal echo,renal pelvis separation and ectopic kidney,etc.Severe chromosomal or genetic abnormalities could exist even when the relative manifestations were not obvious.

Prenatal diagnosis of Pallister-Killian syndrome: a report of two cases / 中华围产医学杂志

This article reported two fetuses diagnosed with Pallister-Killian syndrome (PKS). Amniotic fluid samples of one pregnant woman (case 1), with an abnormal result of non-invasive prenatal test, were analyzed by karyotyping and copy number variation-sequencing (CNV-seq), and samples of the other one (case 2), with a prenatal ultrasound of a lowered spinal conus and an enhanced echo of the renal cortex, were tested for CNV-seq. The chromosome karyotype of case 1 showed 47,XN,+mar[30]/46, XN[10]. CNV-seq results revealed three to four copies of repetition of the p13.33p11.1 segment of chromosome 12, suggesting 12p tetrasomy chimerism in both fetuses. The diagnosis of fetal PKS was confirmed through the combination of multiple technologies (ultrasound, chromosomal karyotype analysis, and CNV-seq). The two pregnancies were terminated after genetic counseling.

Prenatal diagnosis and genetic counseling of 1q21.1 distal microdeletion/microduplication in 14 fetuses / 中华围产医学杂志

Objective:To explore the clinical phenotypes, pregnancy outcomes, and follow-up of fetuses with 1q21.1 distal microdeletion/microduplication, and to provide a basis for prenatal and genetic counseling.Methods:This was a retrospective study involving 14 singleton fetuses with 1q21.1 distal microdeletion/microduplication that were prenatally diagnosed by karyotype analysis and chromosomal microarray analysis (CMA) at Wuxi Maternity and Child Health Care Hospital from January 2017 to June 2022. The results of ultrasound and genetic analysis, pregnancy outcome after genetic counseling, and postnatal follow-up were summarized using descriptive statistical methods.Results:All 14 fetuses had normal karyotypes. Out of the 14 cases, CMA indicated 1q21.1 distal microdeletion in eight cases and 1q21.1 distal microduplication in six cases. The fragments ranged from 813 kb to 4.48 Mb, all of which contained the key region of 1q21.1 microdeletion/microduplication syndrome and were pathogenic copy number variations (CNV). Among eight fetuses with distal 1q21.1 microdeletion, four cases had abnormal prenatal ultrasound findings, including one case with overlapping fingers of left hand and polyhydramnios, two were small for gestational age, and one with small head circumference. Among the six cases who underwent parental origin detection, the microdeletions were de novo in four fetuses and two fetuses were inherited from the parent with normal phenotype. As for six fetuses with distal 1q21.1 microduplication, nasal bone absence or hypoplasia was shown by ultrasound in four cases and no obvious abnormality was found in the other two cases. Parental origin detection was performed in four cases, which found that one case was de novo and the other three cases were inherited from their phenotypically normal parents. After genetic counseling, five families chose to terminate the pregnancies and the remaining nine cases continued the pregnancies to delivery. The last follow-up showed that all of the nine live births grew well, whose ages ranged from seven months to half past five years old. Conclusions:CMA is of great value in prenatal diagnosis of 1q21.1 distal microdeletion/ microduplication. Ones carrying pathogenic CNV may not develop the disease. Combined with ultrasound findings and parental genetic tracing results, individualized genetic counseling and long-term follow-up are of great importance for reasonable guidance in pregnancy outcome and reproduction.

Genetic analysis of homologous Robertsonian translocation trisomy 21 in 12 pedigrees / 中华围产医学杂志

Objective:To analyze the genetic features of homologous Robertsonian translocation trisomy 21.Methods:This retrospective analysis involved 12 pedigrees in which singleton fetuses were prenatally diagnosed with homologous Robertsonian translocation trisomy 21 [46,XX/XY,+21,der(21;21)(q10;q10)] at the Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region from January 2012 to January 2023. Moreover, karyotype analysis results of the parental peripheral blood were obtained. The prenatal diagnosis results and genetic features in the 12 pedigrees were summarized using descriptive statistical analysis.Results:Among the 12 pedigrees, eight cases were de novo and the other four were maternally inherited. Three mothers in the four inherited cases had homologous Robertsonian translocation trisomy 21 and the other one was a homologous Robertsonian translocation carrier. The karyotypes of the four fathers were all normal. There were three families with multiple children, two of the couples with normal karyotypes had normal children, and the other couple had a child with homologous Robertsonian translocation trisomy 21 that was inherited from the mother with the same type of trisomy 21. Non-invasive prenatal testing was performed in two pedigrees during this pregnancy and the results showed that one case was at low risk and one was at high risk of trisomy 21. Further testing of the placenta after labor induction confirmed the low-risk case with low proportion of mosaic trisomy 21 (the proportion was 21% on the maternal side of the placenta and 9% on the fetal side). Conclusions:Most cases of homologous Robertsonian translocation trisomy 21 are de nove and few are inherited. Parents of probands with homologous Robertsonian translocation trisomy 21 should be routinely advised to undergo peripheral blood chromosome examination to find out whether they are carriers of homologous Robertsonian translocation.

Atrial septal defect and hydronephrosis associated with 2q13 microdeletion: a case report and literature review / 中华围产医学杂志

Objective:To investigate the clinical and genetic features of 2q13 microdeletion.Methods:This study retrospectively analyzed the clinical and genetic features and prognosis of an infant who was admitted to the Fourth People's Hospital of Zhenjiang Affiliated to Jiangsu University and diagnosed with 2q13 microdeletion in October 2021. A literature review on the clinical and genetic characteristics of 2q13 microdeletion was conducted by searching CNKI, Wanfang database, Yiigle, VIP database, PubMed, Embase, and Cochrane Library databases up to March 2023, with "2q13 microdeletion" and "2q13" (both in Chinese and English) as the keywords.Results:(1) Case report: A fetus was found to have mild aortic arch stenosis and left hydronephrosis by prenatal ultrasound at 24 +2 gestational weeks. Fetal chromosomal microarray analysis following amniocentesis at 27 +6 weeks of gestation revealed a 2.23 Mb deletion at 2q13q14.1 chromosome, considered a possible pathogenic copy number variation. The newborn was delivered by cesarean section at 38 +5 weeks of gestation. Echocardiography indicated ostium secundum atrial septal defect and ultrasound showed left hydronephrosis. Other examinations detected no abnormalities. Results of imaging reexamination showed no significant changes when followed up by telephone at 13 months after birth, and a continued follow-up was recommended by the pediatrician. No other developmental abnormalities were found. (2) Literature review: There were 64 patients in 32 retrieved literature, and the one case in this report results in 65 cases. The 2q13 microdeletions can be de novo (15.6%, 10/64) or inherited from one of the parents with normal or abnormal phenotypes (35.9%, 23/64). The clinical manifestations include developmental delay (53.3%, 16/30), craniofacial abnormalities (56.8%, 21/37), and congenital heart diseases (35.0%, 14/40). In addition, some cases exhibited mental neurological symptoms with age, such as attention deficit hyperactivity disorder (48.0%, 12/25), autism spectrum disorders (35.7%, 10/28), etc. Conclusions:The 2q13 microdeletion is complex in its clinical characteristics and incomplete in penetrance. Chromosomal microarray analysis is recommended for confirming diagnosis when related phenotypes are identified prenatally. Some cases of 2q13 microdeletion will show neuropsychiatric symptoms with age, suggesting that long-term follow-up is necessary.

A case of 5p15.1-5p15.33 duplication and literature review / 中华神经科杂志

Objective:To analyze the clinical and genetic features of the children with 5p15.1-5p15.33 duplication at the end of the short arm of chromosome 5 (5p).Methods:Clinical data of a 5p15.1-5p15.33 duplicative patient diagnosed in the Department of Pediatric Intensive Care Unit of West China Second University Hospital of Sichuan University in July 2021 were collected, and the characteristics of the patients of 5p duplication syndrome reported in the literatures were summarized and analyzed.Results:The boy was 1 year and 5 months old at the time of admission. The main clinical manifestations included growth restriction and developmental delay after birth, accompanied by craniofacial deformities. At 7 months old, he was diagnosed as epilepsy due to convulsive limbs. At present, he is 2 years old, still has recurrent convulsions, can not raise his head, sit alone, crawl and talk, with hypotonia. Repeated cranial magnetic resonance imaging showed agenesis of the corpus callosum. The child′s parents had normal phenotypes. His copy number variation sequencing results showed partial overlap of chromosome 5p15.1-5p15.33 (chr5:1934522-18905656), which was determined as pathogenic copy number variation according to copy number variations evaluation criteria, and no abnormality was detected in his parents. According to the retrieval strategy set in this study, 10 literatures (all in English, reporting 17 cases) were retrieved, and a total of 22 5p duplication syndrome patients (including this case and 4 cases included in databases) were included. Seventeen of the 22 patients were younger than 14 years old with a onset age of 7 (0, 18) years, and the male to female ratio was about 1.1∶1. Among the 22 patients, craniofacial malformation was found in 19 patients, developmental disorder in 18, bone/muscle dysplasia in 15, autism in 11, attention deficit hyperactivity disorder in 9, mental retardation in 8, obesity in 5, epilepsy in 5, congenital heart dysplasia in 2, hypotonia in 4, strabismus/hyperopia in 2, and corpus callosum dysplasia, endocrine dysfunction, inguinal hernia as well as umbilical hernia in 1, respectively. There were 19 cases of multiple malformation and 3 cases of single malformation.Conclusions:5p15.1-5p15.33 duplication may be the genetic cause of this child. Facial malformation, developmental delay, skeletal/muscular dysplasia, intellectual disability, autism spectrum disorder and attention deficit hyperactivity disorder are the main clinical phenotypes of 5p copy number duplication. Corpus callosum dysplasia may be an extended phenotype of chromosome duplication at this location.

Prenatal diagnosis and genetic analysis of seven fetuses with 16p12.2 microdeletion or microduplication / 中华围产医学杂志

Objective:To investigate the prenatal ultrasonographic features and diagnosis of 16p12.2 copy number variation (CNV).Methods:This retrospective study recruited seven fetuses with 16p12.2 microdeletion/microduplication in the First Affiliated Hospital of Fujian Medical University from January 2017 to December 2021. Data, including the prenatal diagnostic indications, ultrasound findings, karyotypes, genetic testing and mutation tracing results, pregnancy outcomes, and postnatal follow-up data, were summarized with descriptive statistical analysis.Results:Prenatal ultrasound indicated three fetuses with structural abnormalities, including one case each of multiple malformations, interventricular septal defect, and cleft lip and palate. The other four cases were positive for ultrasonic soft markers involving the heart and kidney. The chromosome karyotypes of the seven fetuses were normal. Single nucleotide polymorphism array (SNP array) results showed that four cases had a 381.7-542.4 kb microdeletion containing three genes ( OTOA, METTL9, and IGSF6) in Online Mendelian Inheritance in Man (OMIM) at 16p12.2 (distal region) and three cases had a 484.0-701.7 kb microdeletion/microduplication containing four OMIM genes ( UQCRC2, CDR2, EEF2K, and POLR3E) at 16p12.2 (proximal region). Five (cases 1, 2, 4, 5, and 6) out of the seven fetuses inherited the variants from their phenotypically normal mother/father, and among them, three (cases 2, 4, and 5) were delivered at term and healthy. Two cases (cases 3 and 7) refused to undergo pedigree verification. Case 3, a full-term infant, underwent ventricular septal defect repair three months after birth, and no abnormality was found at 18 months of age. Conclusions:No specific phenotype presents in fetuses with 16p12.2 microdeletion/microduplication in prenatal diagnosis. OTOA gene is the key gene associated with abnormality in the distal region of 16p12.2. Pedigree analysis is conducive to preventing unnecessary termination of pregnancy.

Prenatal phenotypic analysis and genetic counseling for 22q11.21 microdeletion and microduplication syndrome / 中华围产医学杂志

Objective:To analyze the prenatal clinical phenotypes and pregnancy outcomes of fetuses with 22q11.21 microdeletion and microduplication syndrome to provide a basis for clinical genetic counseling.Methods:This retrospective study involved the cases diagnosed with 22q11.21 microdeletion or microduplication by chromosomal microarray analysis (CMA) due to abnormal ultrasound findings, advanced maternal age, or high-risk pregnancies indicated by serum screening in the Prenatal Diagnosis Center of the First Affiliated Hospital of Air Force Medical University from January 2015 to January 2022. Clinical phenotypes and pregnancy outcomes of the fetuses were analyzed and described.Results:Among 9 141 cases referred for CMA during the study period, 77 cases (0.8%) were diagnosed as 22q11.21 microdeletion or microduplication, including 62 (80.5%) with 22q11.21 microdeletion and 15 (19.5%) with microduplication. In the 22q11.21 microdeletion cases, 58 had typical deletion, and four had atypical deletions, but all fetuses carried TBX1 gene that was clearly associated with congenital heart disease. The 15 fetuses with 22q11.21 microduplication including 14 in the typical region and one in the atypical region. Forty-eight (77.4%) out of the 62 fetuses with 22q11.21 microdeletion were complicated by congenital heart defects, including 28 with conotruncal defects. Five of the 15 fetuses with 22q11.21 microduplication were complicated by congenital heart defects. The cases were followed up on telephone at three to six months after the expected date of delivery. Among the 62 cases with 22q11.21 microdeletion, 52 terminated pregnancies, five were lost to follow-up, and five were delivered (one died after one month of premature delivery, one was born with anal advancement and growth retardation, and three were followed up without obvious abnormality). Among the 15 cases with 22q11.21 microduplication, four terminated pregnancies, two were lost to follow-up, and nine gave birth (eight were followed up without obvious abnormality, one grew slowly). Conclusions:The application of CMA in the prenatal diagnosis of 22q11.21 microdeletion and microduplication fetuses, and the comprehensive analysis of clinical manifestations and pregnancy outcome combined with ultrasonic diagnosis are of great significance in guiding the treatment and rehabilitation after birth of an affected child. Genetic counseling for cases with 22q11.21 microdeletion and microduplication syndrome should be cautious and consider ultrasound findings.

Síndrome de microdeleção 2q32 em paciente da Amazônia ocidental / 2q32 microdeletion syndrome in a patient from the western Amazon

Introdução: As deleções intersticiais envolvendo a região 2q31q32 são reconhecidas como um transtorno clínico, envolvendo diversas manifestações como deficiência intelectual, retardo no crescimento, distúrbios comportamentais e dismorfologias faciais. Os números reduzidos de relatos de pacientes acometidos por essa síndrome contribui para que as correlações genótipos-fenótipos sejam difíceis de se fazer. Relato de caso: Paciente com inversão do braço longo do cromossomo 2 [46, XX,inv(2)(q21q33)]. Apresentou ao exame físico dismorfológico fronte proeminente, epicanto, ponte nasal baixa, filtro nasolabial longo e lábio superior fino. Ao exame neurológico, apresentava hipotonia. Discussão: Uma correta interpretação cromossômica pode não só identificar a síndrome de microdeleção como também, descartar ou confirmar possíveis diagnósticos diferenciais, deixando evidente a necessidade e a importância de se reconhecer e documentar os casos (AU).

Introduction: Interstitial deletions involving the 2q31q32 region are recognized as a clinical disorder involving several manifestations, such as intellectual disability, growth retardation, behavioral disorders, and facial dysmorphologies. The reduced number of reports of patients affected by this syndrome contributes to the difficulty of making genotype-phenotype correlations. Case report: Patient with inversion of the long arm of chromosome 2 [46, XX,inv(2)(q21q33)]. On physical examination, he had a prominent forehead, epicanthus, low nasal bridge, long nasolabial philtrum and thin upper lip. Neurological examination showed hypotonia. Discussion: A correct chromosomal interpretation can identify the microdeletion syndrome and rule out or confirm possible differential diagnoses, highlighting the need and importance of recognizing and documenting cases (AU).

Evaluation of Genotoxic and Cytotoxic Effects of Gluten in Male Albino Mice

Gluten is a protein commonly found in daily diets in the form of wheat, barley, rye, and other grains. It serves as the structural component in flour, providing the binding qualities that maintain the shape and texture of food items. This study aimed to investigate the genotoxic and cytotoxic effects of gluten on bone marrow chromosomes and DNA of male albino mice. The animals were divided into four groups: a control group, a negative control group that received an oral dose of 0.02M glacial acetic acid, and two groups that were treated with gluten dissolved in 0.02M glacial acetic acid at doses of 1.5 g/kg and 3.0 g/kg body weight. The treated animals received oral doses with non-consecutively three times a week for a period of four weeks. The study evaluated chromosomal aberrations in the bone marrow, micronucleus test, and DNA damage using the comet assay. The results of the study showed that treatment with 1.5 and 3.0g/kg body weight of gluten induced chromosomal aberrations and damage in DNA content, with an increase in the severity of effects at a higher dose of gluten. The chromosomal aberrations seen included deletion, fragment, centromeric attenuation, centric fusion, ring formation, end to end association, chromosomal gap, beaded chromosomes, and polyploidy. The micronucleus test revealed toxicity in the bone marrow, as shown by appearance of micronuclei in polychromatic erythrocytes and a reduction in the ratio of polychromatic erythrocytes. The comet assay showed a significant increase of DNA damage in the tail length of the comet cells. This study concluded that the treatment with gluten has detrimental effects on the bone marrow chromosomes and DNA of mice, as demonstrated by the increased chromosomal aberrations, micronuclei, and DNA damage observed in the treated mice. So, the use of gluten should be within an acceptable and safe range.

Cytogenetic abnormalities in patients with hematological malignancies in Lahore city, Pakistan / Anormalidades citogenéticas em pacientes com neoplasias hematológicas na cidade de Lahore, Paquistão

Hematological and hematopoietic cells malignancies of the genes and hematopoietic cells are associated with the genetic mutation, often at the chromosomal level. The standard cytogenetic study is widely accepted as one of the main diagnostics and prognostic determinants in patients. Therefore, the current descriptive and cross sectional study sought to determine the cytogenetic analysis of frequent hematological malignancies in Pakistan. A total of 202 peripheral bone marrow or blood samples from patients with benign and malignant hematological malignancy were taken using a conventional G-banding technique. Among enrolled patients, the mean age was 21.5 years ± 23.4, and gender-wise distribution showed a marked predominance of the male 147 (73%) population compared to the female 55 (27%). Patients in the age group (2-10 years) had the highest frequency, 48 (24%), of hematological neoplasms, followed by age (11-20 years) with 40 (20%). Normal karyotypes (46, XX/46, XY) was found in 51% (n=103) patients. Furthermore, the frequency of complex karyotype was 30 (15%), while normal was seen in 171 (85%) patients. Pre-B Acute Lymphoblastic Leukemia (Pre-B ALL) was the most prevalent malignancy of 66 (33%), followed by Chronic Myelogenous Leukemia (CML) of 41 (20%) and Acute Lymphocytic Leukemia of 29 (14%). Translocation was the most prevalent 50 (25%), followed by hypotriploidy 14 (7%) and monosomy 8 (4%) on chromosome aberration analysis. In addition, t(9:22) translocation was found to be 20 (10%) in CML, with the majority in the age group (31-40 years). This study recommends that karyotyping should be tested frequently in hematological conditions because it may provide insight into the relative chromosomal changes associated with particular malignancies.

As neoplasias hematológicas e de células hematopoiéticas dos genes e as células hematopoiéticas estão associadas à mutação genética, geralmente em nível cromossômico. O estudo citogenético padrão é amplamente aceito como um dos principais determinantes diagnósticos e prognósticos em pacientes. Portanto, o presente estudo descritivo e transversal buscou determinar a análise citogenética de neoplasias hematológicas frequentes no Paquistão. Um total de 202 amostras de medula óssea periférica ou sangue de pacientes com malignidade hematológica benigna e maligna foi coletado usando uma técnica convencional de banda G. Entre os pacientes inscritos, a média de idade foi de 21,5 anos ± 23,4, e a distribuição por gênero mostrou uma marcada predominância da população masculina de 147 (73%) em comparação com a feminina de 55 (27%). Pacientes na faixa etária (2-10 anos) tiveram a maior frequência, 48 (24%), de neoplasias hematológicas, seguida da idade (11-20 anos) com 40 (20%). Cariótipos normais (46, XX / 46, XY) foram encontrados em 51% (n = 103) dos pacientes. Além disso, a frequência de cariótipo complexo foi de 30 (15%), enquanto normal foi observada em 171 (85%) pacientes. Leucemia linfoblástica aguda pré-B (LLA Pré-B) foi a doença maligna mais prevalente de 66 (33%), seguida por leucemia mieloide crônica (LMC) de 41 (20%) e leucemia linfocítica aguda de 29 (14%). A translocação foi o 50 mais prevalente (25%), seguido por hipotriploidia 14 (7%) e monossomia 8 (4%) na análise de aberração cromossômica. Além disso, a translocação t (9:22) encontrada foi de 20 (10%) na LMC, com a maioria na faixa etária (31-40 anos). Este estudo recomenda que o cariótipo deve ser testado com frequência em condições hematológicas porque pode fornecer informações sobre as alterações cromossômicas relativas associadas a doenças malignas específicas.

Cytogenetic abnormalities in patients with hematological malignancies in Lahore city, Pakistan

Abstract Hematological and hematopoietic cells malignancies of the genes and hematopoietic cells are associated with the genetic mutation, often at the chromosomal level. The standard cytogenetic study is widely accepted as one of the main diagnostics and prognostic determinants in patients. Therefore, the current descriptive and cross-sectional study sought to determine the cytogenetic analysis of frequent hematological malignancies in Pakistan. A total of 202 peripheral bone marrow or blood samples from patients with benign and malignant hematological malignancy were taken using a conventional G-banding technique. Among enrolled patients, the mean age was 21.5 years ± 23.4, and gender-wise distribution showed a marked predominance of the male 147 (73%) population compared to the female 55 (27%). Patients in the age group (2-10 years) had the highest frequency, 48 (24%), of hematological neoplasms, followed by age (11-20 years) with 40 (20%). Normal karyotypes (46, XX/46, XY) was found in 51% (n=103) patients. Furthermore, the frequency of complex karyotype was 30 (15%), while normal was seen in 171 (85%) patients. Pre-B Acute Lymphoblastic Leukemia (Pre-B ALL) was the most prevalent malignancy of 66 (33%), followed by Chronic Myelogenous Leukemia (CML) of 41 (20%) and Acute Lymphocytic Leukemia of 29 (14%). Translocation was the most prevalent 50 (25%), followed by hypotriploidy 14 (7%) and monosomy 8 (4%) on chromosome aberration analysis. In addition, t(9:22) translocation was found to be 20 (10%) in CML, with the majority in the age group (31-40 years). This study recommends that karyotyping should be tested frequently in hematological conditions because it may provide insight into the relative chromosomal changes associated with particular malignancies.

Resumo As neoplasias hematológicas e de células hematopoiéticas dos genes e as células hematopoiéticas estão associadas à mutação genética, geralmente em nível cromossômico. O estudo citogenético padrão é amplamente aceito como um dos principais determinantes diagnósticos e prognósticos em pacientes. Portanto, o presente estudo descritivo e transversal buscou determinar a análise citogenética de neoplasias hematológicas frequentes no Paquistão. Um total de 202 amostras de medula óssea periférica ou sangue de pacientes com malignidade hematológica benigna e maligna foi coletado usando uma técnica convencional de banda G. Entre os pacientes inscritos, a média de idade foi de 21,5 anos ± 23,4, e a distribuição por gênero mostrou uma marcada predominância da população masculina de 147 (73%) em comparação com a feminina de 55 (27%). Pacientes na faixa etária (2-10 anos) tiveram a maior frequência, 48 (24%), de neoplasias hematológicas, seguida da idade (11-20 anos) com 40 (20%). Cariótipos normais (46, XX / 46, XY) foram encontrados em 51% (n = 103) dos pacientes. Além disso, a frequência de cariótipo complexo foi de 30 (15%), enquanto normal foi observada em 171 (85%) pacientes. Leucemia linfoblástica aguda pré-B (LLA Pré-B) foi a doença maligna mais prevalente de 66 (33%), seguida por leucemia mieloide crônica (LMC) de 41 (20%) e leucemia linfocítica aguda de 29 (14%). A translocação foi o 50 mais prevalente (25%), seguido por hipotriploidia 14 (7%) e monossomia 8 (4%) na análise de aberração cromossômica. Além disso, a translocação t (9:22) encontrada foi de 20 (10%) na LMC, com a maioria na faixa etária (31-40 anos). Este estudo recomenda que o cariótipo deve ser testado com frequência em condições hematológicas porque pode fornecer informações sobre as alterações cromossômicas relativas associadas a doenças malignas específicas.

Chromosomal abnormalities detected by karyotyping among patients with secondary amenorrhea: a retrospective study

ABSTRACT BACKGROUND: Chromosomal abnormalities (CAs) have been described in patients with secondary amenorrhea (SA). However, studies on this association are scarce. OBJECTIVES: To evaluate the frequency and types of CAs detected by karyotyping in patients with SA. DESIGN AND SETTING: This retrospective study was performed in a reference clinical genetic service in South Brazil. METHODS: Data were obtained from the medical records of patients with SA who were evaluated between 1975 and 2022. Fisher's bicaudate exact test and Student's t-test were used, and P < 0.05 was considered significant. RESULTS: Among 43 patients with SA, 14 (32.6%) had CAs, namely del (Xq) (n = 3), 45,X (n = 2), 46,X,r(X)/45,X (n = 2), 46,XX/45,X (n = 1), 46,X,i(q10)/45,X (n = 1), 47,XXX (n = 1), 46,XX/47,XXX (n = 1), 46,XX/47,XX,+mar (n = 1), 45,XX,trob(13;14)(q10;q10)/46,XXX,trob(13;14)(q10;q10) (n = 1), and 46,XX,t(2;21)(q23;q11.2) (n = 1). Additional findings were observed mostly among patients with CA compared with those without CA (P = 0.0021). No difference in the mean age was observed between the patients with SA with or without CAs (P = 0.268025). CONCLUSIONS: CAs are common among patients with SA, especially those with short stature and additional findings. They are predominantly structural, involve the X chromosome in a mosaic, and are compatible with the Turner syndrome. Patients with SA, even if isolated, may have CAs, particularly del (Xq) and triple X.

Cytogenetic abnormalities in patients with hematological malignancies in Lahore city, Pakistan / Anormalidades citogenéticas em pacientes com neoplasias hematológicas na cidade de Lahore, Paquistão

Abstract Hematological and hematopoietic cells malignancies of the genes and hematopoietic cells are associated with the genetic mutation, often at the chromosomal level. The standard cytogenetic study is widely accepted as one of the main diagnostics and prognostic determinants in patients. Therefore, the current descriptive and cross-sectional study sought to determine the cytogenetic analysis of frequent hematological malignancies in Pakistan. A total of 202 peripheral bone marrow or blood samples from patients with benign and malignant hematological malignancy were taken using a conventional G-banding technique. Among enrolled patients, the mean age was 21.5 years ± 23.4, and gender-wise distribution showed a marked predominance of the male 147 (73%) population compared to the female 55 (27%). Patients in the age group (2-10 years) had the highest frequency, 48 (24%), of hematological neoplasms, followed by age (11-20 years) with 40 (20%). Normal karyotypes (46, XX/46, XY) was found in 51% (n=103) patients. Furthermore, the frequency of complex karyotype was 30 (15%), while normal was seen in 171 (85%) patients. Pre-B Acute Lymphoblastic Leukemia (Pre-B ALL) was the most prevalent malignancy of 66 (33%), followed by Chronic Myelogenous Leukemia (CML) of 41 (20%) and Acute Lymphocytic Leukemia of 29 (14%). Translocation was the most prevalent 50 (25%), followed by hypotriploidy 14 (7%) and monosomy 8 (4%) on chromosome aberration analysis. In addition, t(9:22) translocation was found to be 20 (10%) in CML, with the majority in the age group (31-40 years). This study recommends that karyotyping should be tested frequently in hematological conditions because it may provide insight into the relative chromosomal changes associated with particular malignancies.

Resumo As neoplasias hematológicas e de células hematopoiéticas dos genes e as células hematopoiéticas estão associadas à mutação genética, geralmente em nível cromossômico. O estudo citogenético padrão é amplamente aceito como um dos principais determinantes diagnósticos e prognósticos em pacientes. Portanto, o presente estudo descritivo e transversal buscou determinar a análise citogenética de neoplasias hematológicas frequentes no Paquistão. Um total de 202 amostras de medula óssea periférica ou sangue de pacientes com malignidade hematológica benigna e maligna foi coletado usando uma técnica convencional de banda G. Entre os pacientes inscritos, a média de idade foi de 21,5 anos ± 23,4, e a distribuição por gênero mostrou uma marcada predominância da população masculina de 147 (73%) em comparação com a feminina de 55 (27%). Pacientes na faixa etária (2-10 anos) tiveram a maior frequência, 48 (24%), de neoplasias hematológicas, seguida da idade (11-20 anos) com 40 (20%). Cariótipos normais (46, XX / 46, XY) foram encontrados em 51% (n = 103) dos pacientes. Além disso, a frequência de cariótipo complexo foi de 30 (15%), enquanto normal foi observada em 171 (85%) pacientes. Leucemia linfoblástica aguda pré-B (LLA Pré-B) foi a doença maligna mais prevalente de 66 (33%), seguida por leucemia mieloide crônica (LMC) de 41 (20%) e leucemia linfocítica aguda de 29 (14%). A translocação foi o 50 mais prevalente (25%), seguido por hipotriploidia 14 (7%) e monossomia 8 (4%) na análise de aberração cromossômica. Além disso, a translocação t (9:22) encontrada foi de 20 (10%) na LMC, com a maioria na faixa etária (31-40 anos). Este estudo recomenda que o cariótipo deve ser testado com frequência em condições hematológicas porque pode fornecer informações sobre as alterações cromossômicas relativas associadas a doenças malignas específicas.

A bird´s-eye view of chromosomes during meiotic prophase I / Una vista panorámica de los cromosomas en la profase I de la meiosis

ABSTRACT The present review aims to summarize the research carried out in relation to meiosis in birds, especially by observing the protein axes of the chromosomes in prophase I of meiosis. This line of research, initially developed in Argentina, has provided key data in the study of the evolution of sex chromosomes and the mechanisms involved in the frequency and distribution of crossing over in birds, among other topics. Some of these contributions, in addition to those made by other authors, are described also providing the general theoretical framework or the hypotheses that support them.

RESUMEN La presente revisión tiene por objetivo resumir las investigaciones realizadas en relación a la meiosis de las aves, especialmente mediante la observación de los ejes proteicos de los cromosomas en la profase I de la meiosis. Esta línea de investigación, desarrollada inicialmente en Argentina, ha aportado datos clave dentro del estudio de la evolución de los cromosomas sexuales y los mecanismos involucrados en la frecuencia y distribución del crossing over en las aves, entre otros temas. Algunas de estas contribuciones, además de las realizadas por otros autores, se describen proporcionando también el marco teórico general o las hipótesis que las sustentan.

Causes and consequences of DNA content variation in Zea / Causas y consecuencias de la variación del contenido de ADN en Zea

ABSTRACT Cytogenetic evidence indicates that Zea, which comprises maize (Z. mays ssp. mays) and its wild relatives, is an allopolyploid genus. Our research group has carried out numerous cytogenetic studies on Zea species, mainly focused on native Argentinian and Bolivian maize landraces. We found a wide inter- and intraspecific genome size variation in the genus, with mean 2C-values ranging between 4.20 and 11.36 pg. For the maize landraces studied here, it varied between 4.20 and 6.75 pg. The objectives of this work are to analyze the causes of genome size variation and to discuss their adaptive value in Zea. This variation is mainly attributed to differences in the heterochromatin located in the knobs and to the amount of interspersed DNA from retrotransposons. Polymorphisms in presence or absence of B-chromosomes (Bs) and the population frequency of Bs are also a source of genome size variation, with doses ranging between one and eight in the landraces analyzed here. Correlation analysis revealed that the percentage of heterochromatin is positively correlated with genome size. In addition, populations cultivated at higher altitudes, which are known to be precocious, have smaller genome sizes than do those growing at lower altitudes. This information, together with the positive correlation observed between the length of the vegetative cycle and the percentage of heterochromatin, led us to propose that it has an adaptive role. On the other hand, the negative relationship found between Bs and heterochromatic knobs allowed us to propose the existence of an intragenomic conflict between these elements. We hypothesize that an optimal nucleotype may have resulted from such intranuclear conflict, where genome adjustments led to a suitable length of the vegetative cycle for maize landraces growing across altitudinal clines.

RESUMEN La evidencia citogenética indica que el género Zea, el maíz (Z. mays ssp. mays) y sus parientes silvestres, posee un origen alopoliploide. Nuestro grupo de investigación ha realizado numerosos estudios en especies de Zea, principalmente en maíces nativos de Argentina y Bolivia. En este género, hallamos una amplia variación inter e intraespecífica en el tamaño del genoma, con valores 2C medios que oscilan entre 4,20 y 11,36 pg. El valor 2C medio de los maíces nativos estudiados varió entre 4,20 y 6,75 pg. Los objetivos de este trabajo son analizar las causas de la variación del tamaño del genoma en Zea y discutir su valor adaptativo. Esta variación se atribuye principalmente a las diferencias en la heterocromatina de los knobs y en la cantidad de ADN intercalado de los retrotransposones. Otras fuentes de variación son los polimorfismos para presencia/ausencia de cromosomas B (Bs) y para la frecuencia poblacional de Bs en las razas analizadas, con dosis que oscilan entre uno y ocho Bs. El porcentaje de heterocromatina se correlaciona positivamente con el tamaño del genoma. Las poblaciones cultivadas en altitudes altas, que son precoces, tienen tamaños de genoma más pequeños que las que crecen en bajas altitudes. Esta información, junto con la correlación positiva observada entre la duración del ciclo vegetativo y el porcentaje de heterocromatina, nos llevó a proponer el rol adaptativo de la heterocromatina. Por otro lado, la relación negativa encontrada entre Bs y knobs heterocromáticos nos permitió proponer la existencia de un conflicto intragenómico entre estos elementos. Hipotetizamos que de este conflicto intranuclear habría resultado el nucleotipo óptimo, donde ajustes genómicos condujeron a una duración adecuada del ciclo vegetativo en las razas de maíz que crecen a lo largo de clines altitudinales.