Prenatal diagnosis and genetic analysis of a fetus with partial deletion of Yq and mosaicism of 45,X / 中华医学遗传学杂志

OBJECTIVE@#To carry out prenatal diagnosis and genetic analysis for a fetus with disorders of sex development (DSDs).@*METHODS@#A fetus with DSDs who was identified at the Shenzhen People's Hospital in September 2021 was selected as the study subject. Combined molecular genetic techniques including quantitative fluorescence PCR (QF-PCR), multiplex ligation-dependent probe amplification (MLPA), chromosomal microarray analysis (CMA), quantitative real-time PCR (qPCR), as well as cytogenetic techniques such as karyotyping analysis and fluorescence in situ hybridization (FISH) were applied. Ultrasonography was used to observe the phenotype of sex development.@*RESULTS@#Molecular genetic testing suggested that the fetus had mosaicism of Yq11.222qter deletion and X monosomy. Combined with the result of cytogenetic testing, its karyotype was determined as mos 45,X[34]/46,X,del(Y)(q11.222)[61]/47,X,del(Y)(q11.222),del(Y)(q11.222)[5]. Ultrasound examination suggested hypospadia, which was confirmed after elective abortion. Combined the results of genetic testing and phenotypic analysis, the fetus was ultimately diagnosed with DSDs.@*CONCLUSION@#This study has applied a variety of genetic techniques and ultrasonography to diagnose a fetus with DSDs with a complex karyotype.

Variantes citogenéticas en pacientes con síndrome de Turner diagnosticadas en un hospital de tercer nivel de atención en Ecuador / Cytogenetic variants in patients with Turner syndrome diagnosed in a third level care hospital in Ecuador

Resumen Introducción: El Síndrome de Turner (ST) es una alteración cromosómica sexual causada por la ausencia parcial o completa del cromosoma X, además de mosaicismos y otras alteraciones estructurales del cromosoma X o Y; está presente en 1 de 2500 nacidas vivas. Objetivo: Describir las variantes citogenéticas de pacientes con síndrome de Turner y evaluar su asociación con el fenotipo de presentación y la edad del diagnóstico. Método: Estudio retrospectivo de corte transversal de una serie de 82 casos de síndrome de Turner. Los cariotipos fueron realizados utilizando el medio RPMI-1640; las preparaciones de cromosomas se obtuvieron utilizando técnicas estándar y se analizaron mediante bandas GTG con una resolución de 400-450 bandas, donde se contó con 20-50 metafases para reducir la probabilidad de no detección de mosaicismo. Resultados: 45 (55.6%) fueron diagnosticadas, con monosomía clásica del cromosoma X, mientras 29 (35,8%) mostraron anomalías estructurales del cromosoma X y 7 (8,6%) se asociaron a mosaicos numéricos del cromosoma X. Solo 21 (26%) pacientes fueron diagnosticadas por debajo de los 12 años, mientras el resto 60 (74%) se detectaron entre la adolescencia y la adultez. La baja estatura fue una característica universal en todos los grupos de estudio. Conclusiones: Las fórmulas cromosómicas en el síndrome de Turner pueden ser muy variadas y tener diversas implicaciones en el fenotipo; se destaca la baja talla como un criterio clínico relevante en la sospecha clínica.

Abstract Introduction: Turner Syndrome (TS) is a sexual chromosomal alteration caused by the partial or complete absence of the X chromosome, in addition to mosaicisms and other structural alterations of the X or Y chromosome; It is present in 1 in 2,500 live births. Objective: To describe the cytogenetic variants of Turner syndrome patients and to evaluate their association with the phenotype at presentation and age at diagnosis. Methods: Retrospective cross-sectional study of a series of 82 cases of Turner syndrome. Karyotypes were performed using RPMI-1640 medium; Chromosome preparations were obtained using standard techniques and analyzed by GTG banding with a resolution of 400-450 bands where 20-50 metaphases were counted to reduce the probability of missing mosaicism. Results: 45 (55.6%) were diagnosed with classic monosomy of the X chromosome, while 29 (35.8%) showed structural abnormalities of the X chromosome and 7 (8.6%) were associated with numerical mosaics of the X chromosome. Only 21 (26%) patients were diagnosed under 12 years of age, while the rest 60 (74%) were detected between adolescence and adulthood. Short stature was a universal characteristic in all study groups. Conclusions: The chromosomal formulas in Turner syndrome can be variable and have different implications in the phenotype; short stature stands out as a relevant clinical criterion in clinical suspicion.

Genetic Polymorphism of 16 X-STR Loci in Xinjiang Uygur Population / 法医学杂志

OBJECTIVES@#To study the genetic polymorphism and population genetic parameters of 16 X-STR loci in Xinjiang Uygur population.@*METHODS@#The Goldeneye® DNA identification system 17X was used to amplify 16 X-STR loci in 502 unrelated individuals (251 females and 251 males). The amplified products were detected by 3130xl genetic analyzer. Allele frequencies and population genetic parameters were analyzed statistically. The genetic distances between Uygur and other 8 populations were calculated. Multidimensional scaling and phylogenetic tree were constructed based on genetic distance.@*RESULTS@#In the 16 X-STR loci, a total of 67 alleles were detected in 502 Xinjiang Uygur unrelated individuals. The allele frequencies ranged from 0.001 3 to 0.572 4. PIC ranged from 0.568 8 to 0.855 3. The cumulative discrimination power in females and males were 0.999 999 999 999 999 and 0.999 999 999 743 071, respectively. The cumulative mean paternity exclusion chance in trios and in duos were 0.999 999 997 791 859 and 0.999 998 989 000 730, respectively. The genetic distance between Uygur population and Kazakh population was closer, and the genetic distance between Uygur and Han population was farther.@*CONCLUSIONS@#The 16 X-STR loci are highly polymorphic and suitable for identification in Uygur population, which can provide a powerful supplement for the study of individual identification, paternity identification and population genetics.

Clinical phenotype and genetic analysis of MECP2 duplication syndrome / 中华医学遗传学杂志

OBJECTIVE@#To analyze the clinical symptom and parental origin of patients with MECP2 duplication syndrome in order to provide a basis for genetic counseling and prenatal diagnosis.@*METHODS@#Clinical symptoms of four patients who were diagnosed with MECP2 duplication syndrome by copy number variation sequencing (CNV-Seq) were reviewed. The maternal origin of the duplications were verified.@*RESULTS@#All patients were males, and CNV-Seq revealed that they have all harbored a duplication in the Xq28 region spanning 0.32 ~ 0.86 Mb, which were derived from asymptomatic mothers. The clinical symptoms of three patients with three copies included delayed speech, intellectual disability, and muscular hypotonia, while the patient with four copies had died at 6 months after birth, with clinical symptoms including recurrent infections, seizures, and spasticity.@*CONCLUSION@#The four cases of MECP2 duplication syndrome have shown complete penetrance and have all derived from asymptomatic mothers. As a stable and reliable method, CNV-Seq can accurately detect the MECP2 duplication syndrome.

Genetic study of a child carrying a maternally derived unbalanced 46,Y,der(X)t(X;Y)(p22;q11) chromosomal translocation / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for a child featuring short stature, saddle nose, cryptorchidism and mental retardation.@*METHODS@#The child and his parents were subjected to G-banded karyotyping and chromosomal microarray analysis (CMA).@*RESULTS@#The child was found to have a 46,Y,der(X)t(X;Y)(p22;q11)mat karyotype. CMA has revealed a 8.3 Mb deletion at Xp22.33p22.31 and a 43.3 Mb duplication at Yq11.221qter. His mother had a karyotype of 46,X,der(X)t(X;Y)(p22;q11). His father had a normal karyotype.@*CONCLUSION@#The child has carried an unbalanced translocation der(X)t(X;Y) (p22;q11) derived from his mother. His clinical phenotype has correlated with the size and position of X chromosome deletion. Compared with the females, abnormal phenotypes such as mental retardation and growth retardation of male carriers are more severe.

Mutación de protocadherina 19 (PC-DH19), en paciente con epilepsia refractaria / Mutation of protocadherin 19 (PCDH19), in patients with refractory epilepsy

Paciente de 4 años de edad, con epilepsia de difícil manejo, cuya etiología se atribuye a patología autoinmune y que finalmente se diagnostica una mutación de protocadherina (PCDH19). Se discute la fisiopatología, características clínicas, exámenes y los posibles tratamientos.

Four-year-old patient with intractable epilepsy, whose etiology is attributed to autoimmune pathology and who is eventually diagnosed with a protocadherin mutation (PCDH19). Pathophysiology, clinical characteristics, examinations and possible treatments are discussed.

Prenatal diagnosis of a fetus with cleft lip and palate by using chromosomal microarray analysis / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for a fetus with cleft lip and palate.@*METHODS@#Copy number variations (CNVs) in the fetus and his parents were detected with chromosomal microarray analysis (CMA).@*RESULTS@#As revealed by the CMA assay, the fetus has carried a 228 kb deletion in Xp11.22 region and a 721 kb duplication in 9p21.1. Both CNVs were inherited from the parents. The CNV in Xp11.22 was predicted to be pathogenic by involving the PHF8 gene, whilst the CNV in 9p21.1 was predicted to be benign.@*CONCLUSION@#Deletion of the Xp11.22 region probably underlies the cleft lip and palate in this fetus.

Advance in research on microdeletion/microduplications at Xp22.3 / 中华医学遗传学杂志

With the application of BACs-on-Beads (BoBs) and array-comparative genome hybridization (aCGH) technologies in prenatal diagnosis, microdeletion/microduplications at Xp22.3 have been frequently detected. However, the relatively high prevalence and lack of knowledge of such disorders have brought difficulties for clinical genetic counseling. Here, recent progress of research on microdeletion/microduplications at Xp22.3, including epidemiology, pathogenesis, clinical manifestation, and prenatal diagnosis, is reviewed.

Prenatal diagnosis and genetic analysis of a fetus with der(X)t(X;Y)(p22.3;q11.2) / 中华医学遗传学杂志

OBJECTIVE@#To explore the pathogenesis and genetic characteristics of a fetus with a der(X)t(X;Y)(p22.3;q11.2) karyotype.@*METHODS@#G-banding karyotyping analysis, BoBs (BACs-on-Beads) assay, and single nucleotide polymorphism array (SNP-array) were used to delineate the structural chromosomal aberration of the fetus. The parents of the fetus were also subjected to karyotyping analysis.@*RESULTS@#The fetus and its mother were both found to have a karyotype of 46,X,add(X)(p22), while the father was normal. BoBs assay indicated that there was a lack of Xp22 but a gain of Yq11 signal. SNP-array confirmed that the fetus and its mother both had a 7.13 Mb deletion at Xp22.33p22.31 (608 021-7 736 547) and gain of a 12.52 Mb fragment at Yq11.221q11.23 (16 271 151-28 788 643).@*CONCLUSION@#The fetus was determined to have a karyotype of 46,X,der(X)t(X;Y)(p22.3;q11.2)mat. The combined use of various methods has facilitated delineation of the fetal chromosomal aberration and prediction of the risk prediction for subsequent pregnancy.

Investigation of chromosomal alterations in patients with Alzheimer's disease in the state of Amazonas, Brazil / Investigação de alterações cromossômicas em pacientes com doença de Alzheimer no estado do Amazonas, Brasil

ABSTRACT Alzheimer's disease (AD) has as its main characteristic the deterioration of cerebral functions. Its etiology is still complex and undefined despite the progress made in understanding its neurological, infectious, biochemical, genetic and cytogenetic mechanisms. Considering this, the aim of this study was to investigate the presence of chromosomal alterations in the peripheral blood lymphocytes, and to verify if there was a high frequency of these alterations in patients diagnosed with AD at the University Hospital GetúLio Vargas Outpatient Clinic Araújo Lima in Manaus, Amazonas, Brazil. Among the nine patients in the AD group, only one patient did not have metaphases with chromosomal alterations (2n = 46,XX), while eight patients with AD showed numerical chromosomal alterations, classified as X chromosome aneupLoidy (2n = 45,X) and double aneupLoidy (2n = 44,X,-X,-10; 2n = 44,X,-X,-13 and 2n = 44,X,-X,-21). In the control group, no chromosomal changes were found in the karyotypes of these individuals. Therefore, the karyotypes of patients with AD undergo chromosomal alterations at different levels. These findings are being described for the first time in the population of Amazonas, and they highlight the importance of the inclusion of cytogenetic investigations in the routine management of patients with AD.

RESUMO Doença de Alzheimer (DA) tem como principal característica a deterioração das funções cerebrais. Quanto a sua etiologia ainda é complexa e indefinida, apesar do progresso alcançado na compreensão de seus mecanismos neurológicos, infecciosos, bioquímicos, genéticos e citogenéticos. Considerando isto, nós investigamos a presença de alterações cromossômicas nos Linfócitos de sangue periférico e verificamos se há uma alta frequência dessas alterações em pacientes já diagnosticados com doença de Alzheimer no Hospital Universitário Getulio Vargas / Ambulatório Araújo Lima, Manaus / Amazonas / Brasil. Assim, dos 09 pacientes do grupo DA, somente 01 paciente não apresentou metáfases com alterações cromossômicas (2n = 46,XX) enquanto que 08 pacientes com DA apresentaram alterações cromossômicas numéricas, sendo classificadas como aneupLoidia do cromossomo X (2n = 45,X) e aneupLoidia dupLa (2n = 44,X,-X,-10; 2n = 44,X,-X,-13 e 2n = 44,X,-X,-21). No grupo controle, não foram encontradas aLterações cromossômicas nos cariótipos desses indivíduos. Estes achados para a popuLação do Amazonas/ BrasiL estão sendo descritos pela primeira vez. Os cariótipos de pacientes com DA sofrem aLterações cromossômicas em diferentes níveis e demonstraram a importância das investigações citogenéticas no manejo rotineiro de pacientes com DA.

Prenatal diagnosis of monochorionic-diamniotic twins discordant for 45,X/46,XX mosaicism / 中华医学遗传学杂志

OBJECTIVE@#To explore the prenatal screening and diagnosis for a pair of monochorionic-diamniotic (MCDA) twins discordant for 45,X/46,XX mosaicism.@*METHODS@#Amniotic fluid samples were taken from both twins for whom non-invasive prenatal testing has signaled a high risk for sex chromosomal abnormality. Uncultured amniotic fluid was analyzed by fluorescence in situ hybridization (FISH) and single nucleotide polymorphism array (SNP-array). Conventional G-banded karyotyping analysis was performed on the cultured amniotic fluid.@*RESULTS@#Metaphase chromosome analysis showed that one of the twins had a mos 45,X[11]/46,XX[26] karyotype, while the other had a normal karyotype. FISH and SNP-array applied on uncultured amniotic fluid revealed about 30% mosaicism in one of the twins. The twins were confirmed to be monozygotic by SNP-array analysis.@*CONCLUSION@#To avoid confusion arising from discordant karyotypes in MCDA twins with abnormal non-invasive prenatal testing (NIPT) results, dual amniocentesis should be carried out to obtain amniotic fluid samples for chromosomal as well as molecular analysis. To determine the ratio of 45,X and 46,XX cells in Turner syndrome can provide valuable information for prenatal genetic counseling.

Two cases of rare diseases with abnormalities of X chromosome / 中华医学遗传学杂志

OBJECTIVE@#To explore the clinical features and genetic diagnosis of two cases with rare diseases and X chromosome abnormalities.@*METHODS@#Multiple ligation-dependent probe amplification (MLPA) and karyotype analysis were carried out on an 8-year-old girl who was diagnosed with Duchenne muscular dystrophy. Karyotype analysis and PCR assay for SRY and AZF genes were carried out for a-2-month-old male infant with short penis.@*RESULTS@#The girl, who featured short stature and cubitus valgus, was diagnosed as Turner syndrome with a karyotype of 46,X,i(Xq). The male infant was detected with a karyotype of 45,X, with presence of SRY gene but absence of AZF gene.@*CONCLUSION@#Both cases may be associated with abnormalities of X chromosome. Genetic testing can facilitate early diagnosis and clinical intervention for such patients.

Haploidentical allogenetic hematopoietic stem cell transplantation for X-linked adrenoleukodystrophy / 北京大学学报(医学版)

OBJECTIVE@#X-linked adrenoleukodystrophy (ALD) is a severe inherited disorder leading to rapid neurological deterioration and premature death. Allogeneic hematopoietic stem cell transplantation (HSCT) is still the only treatment that halts the neurologic symptoms in ALD. However, many patients lack suitable human leukocyte antigen (HLA) matched related donors and must rely on alternative donors for a source of stem cells. The purpose of this study was to explore the outcomes of haploidentical allogeneic stem cell transplantation for ALD patients.@*METHODS@#Between December 2014 and December 2018, eight children with ALD lacking HLA matched related or unrelated donors were treated with haploidentical allogeneic hematopoietic stem cell transplantation. The patients received conditioning regimen with busulfan 9.6 mg/kg, cyclophosphamide 200 mg/kg and fludarabine 90 mg/m2. Graft-versus-host disease (GVHD) prophylaxis consisted of anti-human thymocyte globulin, cyclosporine A, mycophenolate mofetil and short course of methotrexate.@*RESULTS@#All the 8 children received allogeneic stem cell transplants from their fathers. The median age of the recipients was 8 (range: 5-12) years. The median age of the donors was 36 (range: 32-40) years. All the recipients received granulocyte colony-stimulating factor (G-CSF) mobilized bone marrow and peripheral blood-derived stem cells. The median number of total mononuclear cells dose and CD34+ dose was 10.89 (range: 9.40-12.16)×108/kg and 7.06 (range: 0.74-7.80)×106/kg, respectively. Neutrophil engraftment occurred a median of 11 days (range:8-13 days) after transplantation. Platelet engraftment occurred a median of 10 days (range:8-12 days) after transplantation. All the patients achieved complete donor chimerism at the time of engraftment. Four patients had grades II-IV acute GVHD and 1 had chronic graft-versus-host disease. No severe chronic GVHD occurred. Among all the children, 2 had cytomegalovirus (CMV) DNAemia and 2 Epstein-Barr virus (EBV) DNAemia. Overall, seven of them survived and had no major complications related to transplantation. One died of cerebral hernia after epilepsy 125 days after transplantation.@*CONCLUSION@#The preliminary observation demonstrates that haploidentical allogeneic stem cell transplantation with this novel regimen could successfully achieve full donor chimerism in ALD patients. According to our experience, haploidentical allogeneic hematopoietic stem cell transplantation is safe and feasible in the treatment of X-linked adrenoleukodystrophy.

Protocol for chromosome-specific probe construction using PRINS, micromanipulation and DOP-PCR techniques

ABSTRACT Chromosome-specific probes have been widely used in molecular cytogenetics, being obtained with different methods. In this study, a reproducible protocol for construction of chromosome-specific probes is proposed which associates in situ amplification (PRINS), micromanipulation and degenerate oligonucleotide-primed PCR (DOP-PCR). Human lymphocyte cultures were used to obtain metaphases from male and female individuals. The chromosomes were amplified via PRINS, and subcentromeric fragments of the X chromosome were microdissected using microneedles coupled to a phase contrast microscope. The fragments were amplified by DOP-PCR and labeled with tetramethyl-rhodamine-5-dUTP. The probes were used in fluorescent in situ hybridization (FISH) procedure to highlight these specific regions in the metaphases. The results show one fluorescent red spot in male and two in female X chromosomes and interphase nuclei.

Genetic study of a fetus with a de novo Xp22.33;Yp11.2 translocation / 中华医学遗传学杂志

OBJECTIVE@#To delineate cytogenetic and molecular abnormalities of a fetus carrying a de novo 46,X,der(X),t(X;Y)(p22.3;p11.2).@*METHODS@#G-banded karyotyping and next-generation sequencing (NGS) were used to analyze the fetus, his father and sister. Single nucleotide polymorphism-based arrays (SNP-array), multiple PCR and fluorescence in situ hybridization (FISH) were utilized to verify the result.@*RESULTS@#G-banded karyotyping at 320 bands showed that the fetus had a normal karyotype, while NGS has identified a 3.58 Mb microdeletion at Xp22.33 and a Y chromosomal segment of about 10 Mb at Yp11.32p11.2. With the sequencing results, high-resolution karyotyping at 550-750 bands level has determined the fetus to be 46,X,der(X)t(X;Y)(p22.3;p11.2). The result was confirmed by PCR amplification of the SRY gene, FISH and SNP-array assays. The karyotypes of his father and sister were both normal. His sister also showed no amplification of the SRY gene, and her NGS results were normal too, suggesting that the karyotype of the fetus was de novo.@*CONCLUSION@#Combined karyotyping, NGS, SNP-array, PCR and FISH assay can facilitate diagnosis of XX disorder of sex development.

Síndrome de Turner en una adolescente / Turner syndrome in an adolescent

Se presenta el caso clínico de una adolescente ecuatoriana de 17 años de edad, blanca, quien nació producto de un embarazo normal y parto eutócico. Posterior al nacimiento se le realizó estudio genético que mostró la presencia de un cariotipo X0, por lo cual se le diagnosticó síndrome de Turner. A los 3 años fue operada de hipoplasia del arco aórtico con una evolución favorable. En la actualidad la paciente tiene baja talla con orejas de baja implantación, así como implantación alta del cabello en la nuca, tórax plano en forma de escudo, escaso bello pubiano y ausencia de menstruación

The case report of a 17 years Ecuadorian white adolescent is presented who was born from a normal pregnancy and eutocic delivery. After birth, a genetic study that showed the presence of a X0 Karyotype was carried out, reason why she was diagnosed Turner syndrome. She was operated of hypoplastic aortic arch when she was 3 years with a favorable clinical course. At the present time the patient has short height with ears of low implantation, as well as high implantation of the hair in the back of the neck, flat thorax in shield form, scarce pubic hair and amenorrhea

Analysis a family with partial Xq deletion / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To analyze partial deletion of the long arm of X chromosome in a family and explore the mechanism underlying its phenotypes.</p><p><b>METHODS</b>G-banding technique was employed to analyze the karyotypes of the subjects, and fluorescence in situ hybridization (FISH) was used to analyze their X chromosomes with Xpter, Xqter and WCPX probes.</p><p><b>RESULTS</b>The karyotypes of the proband, her mother and her fetus were all 46,X,del(X)(q24). Combined FISH and karyotyping analysis suggested that the proband and her fetus both carried a Xq24q27.3 deletion.</p><p><b>CONCLUSION</b>The Xq24q27.3 deletion carried by the family is closely related with premature ovarian failure but not with short stature, gonadal dysgenesis and primary amenorrhea.</p>

Prenatal diagnosis and follow-up of a case with Lowe syndrome caused by interstitial deletion of Xq25-26 / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To report on a sporadic case of Lowe syndrome diagnosed prenatally with ultrasound examination and genetic testing.</p><p><b>METHODS</b>Detailed sonographic fetal screening was performed by an experienced sonographer at 32 weeks of gestation. Fetal cranial magnetic resonance imaging (MRI) was applied to detect potential brain abnormality. Chromosomal microarray analysis (CMA) was conducted on amniotic fluid sample from the fetus and peripheral blood sample from the mother.</p><p><b>RESULTS</b>Congenital cataract and enlarged posterior fossa were detected by fetal ultrasound screening. Fetal cranial MRI found hypoplasia of the gyrus. CMA revealed that the fetus has carried a 633 kb deletion at Xq25-26.1 which encompassed the OCRL gene. The mother was a carrier of the same deletion. Clinical examination after birth confirmed that the neonate was affected with Lowe syndrome in addition with an atrial septal defect.</p><p><b>CONCLUSION</b>Prenatal diagnosis of Lowe syndrome without a family history largely depends on fetal imaging. Should cataract be found by ultrasound screening, fetal MRI may be considered to rule out central nervous system anomalies. CMA assay should also be considered to facilitate the diagnosis.</p>

New Advances in Human X Chromosome Status from a Developmental and Stem Cell Biology

Recent advances in stem cell biology have dramatically increased the understanding of molecular and cellular mechanism of pluripotency and cell fate determination. Additionally, pluripotent stem cells (PSCs), including embryonic stem cells and induced pluripotent stem cells, arose as essential resources for disease modeling and cellular therapeutics. Despite these advancements, the epigenetic dysregulation in pluripotency such as the imprinting status, and X chromosome dosage compensation, and its consequences on future utility of PSCs yet remain unresolved. In this review, we will focus on the X chromosome regulation in human PSCs (hPSCs). We will introduce the previous findings in the dosage compensation process on mouse model, and make comparison with those of human systems. Particularly, the X chromosome activation status of human preimplantation embryos, and the regulation of the active X chromosome by human specific lincRNA, X Active Coating Transcript (XACT), will be discussed. We will also discuss the recent findings on higher order X chromosome architecture, and abnormal X chromosome status in hPSCs.

Clinical manifestation and cytogenetic analysis of 607 patients with Turner syndrome / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To explore the correlation between cytogenetic findings and clinical manifestations of Turner syndrome.</p><p><b>METHODS</b>607 cases of cytogenetically diagnosed Turner syndrome, including those with a major manifestation of Turner syndrome, were analyzed with conventional G-banding. Correlation between the karyotypes and clinical features were analyzed.</p><p><b>RESULTS</b>Among the 607 cases, there were 154 cases with monosomy X (25.37%). Mosaicism monosomy X was found in 240 patients (39.54%), which included 194 (80.83%) with a low proportion of 45,X (3 ≤ the number of 45, X ≤5, while the normal cells ≥ 30). Structural X chromosome abnormalities were found in 173 patients (28.50%). A supernumerary marker chromosome was found in 40 cases (6.59%). Most patients with typical manifestations of Turner syndrome were under 11 years of age and whose karyotypes were mainly 45,X. The karyotype of patients between 11 and 18 years old was mainly 45,X, 46,X,i(X)(q10) and mos45,X/46,X,i(X)(q10), which all had primary amenorrhea in addition to the typical clinical manifestations. The karyotype of patients over 18 years of age were mainly mosaicism with a low proportion of 45,X, whom all had primary infertility. 53 patients had a history of pregnancy, which included 48 with non-structural abnormalities of X chromosome and 5 with abnormal structure of X chromosome.</p><p><b>CONCLUSION</b>Generally, the higher proportion of cells with an abnormal karyotype, the more severe were the clinical symptoms and the earlier clinical recognition. Karyotyping analysis can provide guidance for the early diagnosis of Turner syndrome, especially those with a low proportion of 45,X.</p>