Results of carrier screening for Spinal muscular atrophy among 35 145 reproductive-aged individuals from Dongguan region / 中华医学遗传学杂志

OBJECTIVE@#To carry out carrier screening for Spinal muscular atrophy (SMA) in reproductive-aged individuals from Dongguan region and determine the carrier frequency of SMN1 gene mutations.@*METHODS@#Reproductive-aged individuals who underwent SMN1 genetic screening at the Dongguan Maternal and Child Health Care Hospital from March 2020 to August 2022 were selected as the study subjects. Deletions of exon 7 and 8 (E7/E8) of the SMN1 gene were detected by real-time fluorescence quantitative PCR (qPCR), and prenatal diagnosis was provided for carrier couples by multiple ligation-dependent probe amplification (MLPA).@*RESULTS@#Among the 35 145 subjects, 635 were found to be carriers of SMN1 E7 deletion (586 with heterozygous E7/E8 deletion, 2 with heterozygous E7 deletion and homozygous E8 deletion, and 47 with sole heterozygous E7 deletion). The carrier frequency was 1.81% (635/35 145), with 1.59% (29/1 821) in males and 1.82% (606/33 324) in females. There was no significant difference between the two genders (χ² = 0.497, P = 0.481). A 29-year-old woman was found to harbor homozygous deletion of SMN1 E7/E8, and was verified to have a SMN1∶SMN2 ratio of [0∶4], none of her three family members with a [0∶4] genotype had clinical symptoms. Eleven carrier couples had accepted prenatal diagnosis, and one fetus was found to have a [0∶4] genotype, and the pregnancy was terminated.@*CONCLUSION@#This study has determined the SMA carrier frequency in Dongguan region for the first time and provided prenatal diagnosis for carrier couples. The data can provide a reference for genetic counseling and prenatal diagnosis, which has important clinical implications for the prevention and control of birth defects associated with SMA.

Otimização de protocolo para detecção de DNA de Trypanosoma cruzi em polpa de açaí (Euterpe oleracea) / Protocol optimization for the detection of Trypanosoma cruzi DNA in açai (Euterpe oleraceae) pulp

A doença de Chagas, enfermidade causada pelo protozoário Trypanosoma cruzi, tem sido relacionada com frequência à transmissão oral pelo consumo de açaí. Métodos moleculares que fornecem uma identificação rápida e precisa do patógeno para a detecção da presença do parasita são de extrema importância para a detecção da presença do parasita neste alimento. Este estudo teve como objetivo otimizar a detecção de DNA de T. cruzi em polpa de açaí por meio da reação em cadeia da polimerase (PCR). Foram preparadas várias diluições das formas tripomastigotas de T. cruzi DTU TcI cultivadas em meio de cultivo Liver Infusion Tryptose. O DNA de T. cruzi foi extraído das células e submetido à PCR. Posteriormente, as diluições da cultura foram adicionadas às polpas de açaí para avaliar o limite de detecção do novo ensaio de PCR otimizado. Mostramos que nosso ensaio pode detectar DNA de T. cruzi em polpas de açaí na concentração de 1.08 × 10-10 ng µL-1. Concluímos que a metodologia desenvolvida se mostra eficaz e pode ser uma ferramenta importante para a detecção de contaminação por T. cruzi em açaí.(AU)

Carrier screening model for Duchenne muscular dystrophy for women of reproductive age based on a pre-pregnancy birth defect control platform / 中华医学遗传学杂志

OBJECTIVE@#To establish a screening model for females of reproductive age carrying Duchenne muscular dystrophy (DMD) variants based on a current community health examination platform.@*METHODS@#A total of 61 870 participants were recruited between October 2017 and October 2019. Serum creatine kinase (CK) was measured with a Roche Cobasc 701/702 using an enzymatic rate method. Genetic testing was offered to those with a CK level of ≥ 200 U/L. For carriers of DMD variants, genetic counseling and follow up were provided.@*RESULTS@#For the 61 870 females participating in the program, 1078 were found with raised serum CK (≥ 200 U/L), of which 618 (57.33%) accepted CK re-measurement after at least a two-week interval. One hundred and twenty cases were found with sustained serum CK elevation, of which 6 were confirmed to be definite DMD carriers regardless of family history. Genetic testing was provided to 33 females with a family history for DMD, and 13 were determined as definite carriers. An affected fetus was detected by prenatal diagnosis. After genetic counseling, the parents had opted induced abortion.@*CONCLUSION@#Large-scale DMD carrier screening through a three-step approach based on the current community health examination platform is both feasible and cost effective.

Analysis of the population structure and genetic diversity of the red swamp crayfish (Procambarus clarkii) in China using SSR markers

BACKGROUND: Procambarus clarkii produces high-quality, delicious meat that is high in protein, low in fat, and rich in calcium and phosphorus. It has become an important aquatic resource in China. Our objectives are (i) to analyze the level of genetic diversity of P. clarkii populations; (ii) to explore the genetic differentiation (Gst); and (iii) to propose appropriate strategies for the conservation. RESULTS: In this study, Shannon's index (I) and Nei's gene diversity index (H) for P. clarkii were high (I = 0.3462 and H = 0.2325 on average and I = 0.6264, H = 0.4377 at the species level) based on the SSR markers. The expected heterozygosity value of 17 microsatellite loci in 25 crayfish populations was 0.9317, the observed heterozygosity value was 0.9121, and the observed number of alleles per locus was 2.000; and the effective number of alleles per locus was 1.8075. Among the P. clarkii populations, the inbreeding coefficient within populations (Fis) was 0.2315, overall inbreeding coefficient (Fit) was 0.4438, genetic differentiation coefficient among populations (Fst) was 0.3145 and gene differentiation (Gst) was 0.4785 based on SSR analyses. The cluster analysis results obtained by unweighted pair-group method with arithmetic mean (UPGMA) analysis, principal coordinate analysis (PCoA) and STRUCTURE analysis were similar. A mantel test showed that the isolation-by-distance pattern was not significant. CONCLUSIONS: The high Gst among P. clarkii populations is attributed to genetic drift and geographic isolation. The results indicated that more P. clarkii populations should be collected when formulating conservation and aquaculture strategies.

Costo-efectividad de la prueba de secuenciación del gen CFTR para portadores asintomáticos en la población colombiana / Cost-effectiveness of the CFTR gene-sequencing test for asymptomatic carriers in the Colombian population

Introducción. La fibrosis quística es una enfermedad genética de carácter autosómico recesivo clasificada como enfermedad huérfana de alto costo. Objetivo. Determinar la razón de costo-efectividad de la prueba diagnóstica de secuenciación del gen CFTR para los portadores asintomáticos familiares en primer, segundo y tercer grados de consanguinidad. Materiales y métodos. Se hizo una búsqueda sistemática sobre la evaluación de las características operativas de la prueba diagnóstica y los modelos de árbol de decisiones en estudios de costo-efectividad. Se elaboró un modelo de árbol de decisiones tomando como unidad de análisis la prevención de futuras concepciones. Los costos de la enfermedad se obtuvieron del reporte de alto costo del Ministerio de Salud de Colombia. Los costos de la prueba se obtuvieron de laboratorios nacionales. Se hizo un análisis de sensibilidad, determinístico y probabilístico, con la perspectiva del tercer pagador y horizonte a un año. Resultados. Se obtuvo una razón incremental de costo-efectividad (RICE) de USD$ 5.051,10 por obtener 10,89 % más de probabilidades de evitar el nacimiento de un niño enfermo con fibrosis quística por pareja. Para los familiares de segundo y tercer grados, se encontró una RICE de USD$ 19.380,94 y USD$ 55.913,53, respectivamente, al aplicar el PIB per cápita. Esta tecnología fue costo-efectiva en 39 %, 61,18 % y 74,36 % para 1, 2 y 3 PIB per cápita en familiares de primer grado de consanguinidad. Conclusiones. La prueba genética de detección de portadores del gen CFTR resultó costo-efectiva dependiendo del umbral de la disponibilidad de pagar, y de los supuestos y limitaciones establecidas en el modelo.

Introduction: Cystic fibrosis is an autosomal recessive genetic disease classified as a high- cost orphan disease. Objective: To determine the cost-effectiveness ratio of the diagnostic test for the CFTR gene-sequencing in asymptomatic family carriers in the first, second, and third degree of consanguinity. Materials and methods: We conducted a systematic search evaluating operative characteristics of the diagnostic test and decision-tree models in cost-effectiveness studies. A decision-tree model was elaborated taking prevention of future conceptions as a unit of analysis. We obtained the costs of the disease from the high-cost report of the Ministerio de Salud y Protección Social. The costs of the test were referenced by national laboratories. We carried out a deterministic and probabilistic sensitivity analysis with a third-payer perspective and a one-year horizon. Results: An ICER of USD$ 5051.10 was obtained as the incremental cost for obtaining 10.89% more probability of avoiding the birth of a child with cystic fibrosis per screened couple. For family members in second and third degrees, the ICER was USD$ 19,380.94 and USD$ 55,913.53, respectively, evidenced when applying the GDP per capita. This technology was cost-effective in 39%, 61.18%, and 74.36% for 1, 2, and 3 GDP per capita in first degree of consanguinity relatives. Conclusions: The genetic test for the detection of CFTR gene carriers was cost-effective depending on the threshold of availability to pay and the assumptions and limitations established in the model.

Avances en el diagnóstico de la enfermedad granulomatosa crónica: primer estudio familiar en Cuba / Advances in the diagnosis of chronic granulomatous disease: the first family study in Cuba

Introducción: La enfermedad granulomatosa crónica es una inmunodeficiencia primaria causada por mutaciones en la enzima NADPH oxidasa. Esta compromete la producción de especies reactivas del oxígeno, que son importantes contra patógenos. La prueba de la oxidación de la dihidrorodamina es un método eficaz para diagnosticar la enfermedad. Objetivo: Demostrar la utilidad de la prueba de la oxidación de la dihidrorodamina y del patrón de herencia en la confirmación del diagnóstico de la enfermedad granulomatosa crónica de un paciente. Métodos: Estudio de caso de una familia con diagnóstico de enfermedad granulomatosa crónica. Se tomó muestra de sangre periférica para citometría de flujo a tres individuos. Se realizó la prueba de la oxidación de la dihidrorodamina bajo estímulo con acetato de forbolmiristato y se evaluaron las subpoblaciones linfocitarias. Las muestras se leyeron en un citómetro GALLIOS, Beckman Coulter. Los datos obtenidos se analizaron en el programa informático Kaluza. Resultados: El paciente masculino tuvo un valor de oxidación de la dihidrorodamina positiva de 0,87 por ciento, que confirmó un patrón de herencia ligado al cromosoma X; mientras que la madre y hermana gemela portadoras tuvieron valores de 46,76 por ciento y 37,32 por ciento, respectivamente. Se encontraron alteraciones en las subpoblaciones linfocitarias. Conclusiones: La prueba de la oxidación de la dihidrorodamina es un método muy efectivo, rápido y sencillo que confirma el diagnóstico de la enfermedad granulomatosa crónica y determina el patrón de herencia y fenotipo de la enfermedad. Además, permite identificar a las mujeres portadoras según la distribución de los neutrófilos normales y los que tienen el gen CYBB mutado(AU)

Introduction: Chronic granulomatous disease is a primary immunodeficiency caused by mutations in the NADPH oxidase enzymes. This compromises the production of oxygen reactive species, which are important against pathogens. The dihydrorhodamine oxidation test is an effective method for diagnosing the disease. Objective: To demonstrate the usefulness of the dihydrorhodamine oxidation test and the inheritance pattern in confirming the diagnosis of chronic granulomatous disease in a patient. Methods: A case study of a family with a diagnosis of chronic granulomatous disease. A peripheral blood sample was taken from three individuals and by flow cytometry. The dihydrorhodamine oxidation test was performed under stimulation with phorbolmyristate acetate, and lymphocyte subpopulations were evaluated. The samples were read on a GALLIOS, Beckman Coulter cytometer. The data obtained were analyzed using the computer program Kaluza. Results: The male patient had a positive dihydrorhodamine oxidation value of 0.87 percent, which confirmed an inheritance pattern linked to the X chromosome; while the carrier mother and twin sister had values 8203;8203;of 46.76 percent and 37.32 percent, respectively. Alterations were found in the lymphocyte subpopulations. Conclusions: The dihydrorhodamine oxidation test is a very effective, fast and simple method that confirms the diagnosis of chronic granulomatous disease and determines the inheritance pattern and phenotype of the disease. In addition, it allows the identification of female carriers according to the distribution of normal neutrophils and those with the CYBB mutation(AU)

Enfermedad por hemoglobina H: primer caso de dobles heterocigotos hemoglobina Constant Spring / Sudeste Asiático en Costa Rica / Hemoglobin H disease: first case of double heterozygous hemoglobin Constant Spring / Southeast Asian in Costa Rica

Resumen La enfermedad por hemoglobina H es un cuadro clínico que se presenta en las alfa talasemias, las cuales son enfermedades que cursan con anemia microcítica hipocrómica, debidas principalmente a deleciones en el gen de alfaglobina, lo que disminuye la producción de la cadena de alfa globina y promueve la formación de variantes de hemoglobina. Cuando se detectan variantes de hemoglobina en las alfa talasemias, por lo general, se debe a genotipos homocigotas o dobles heterocigotas para mutaciones y deleciones del gen de alfa globina coheredadas. En este artículo se describe el primer caso en Costa Rica, de dos hermanos con enfermedad por hemoglobina H, que fenotípicamente presentaron las variantes de hemoglobina H y hemoglobina Constant Spring en el análisis electroforético de la hemoglobina, y cuyo análisis molecular del gen de alfa globina detectó tanto la deleción sudeste asiático como la mutación para hemoglobina Constant Spring, siendo diagnosticados como dobles heterocigotos por alfa talasemia (genotipo --SEA/ααCS).

Abstract Hemoglobin H disease occurs in patients with alpha thalassemia, diseases associated with hypochromic microcytic anemia, mainly due to deletions in the alpha globin gene, which decreases the production of the alpha globin chain and promotes the formation of hemoglobin variants. When hemoglobin variants are detected in alpha thalassemias it is usually due to homozygoys or doublé heterozygous genotypes, for mutations and deletions of the alpha globin gene. This article describes the first case in Costa Rica of two siblings with hemoglobin H disease, who phenotypically presented the hemoglobin H and Constant Spring hemoglobin variants in the electrophoretic analysis of the hemoglobin, and whose molecular DNA analysis of the alpha globin gene detected both, the Southeast Asian deletion and the mutation for Constant Spring Hemoglobin, being diagnosed as compound heterozygous for alpha thalassemia (genotipe --SEA/ααCS).

Result of carrier screening for spinal muscular atrophy among 3049 reproductive-age individuals from Yunnan region / 中华医学遗传学杂志

OBJECTIVE@#To perform carrier screening for spinal muscular atrophy (SMA) among 3049 reproductive-age individuals from Yunnan region and determine the copy number of survival motor neuron (SMN) gene and carrier frequencies.@*METHODS@#Multiplex ligation-dependent probe amplification (MLPA) was used to determine the copy number of exon 7 of SMN1 and SMN2 genes and identify those with a single copy of SMN1 gene. Prenatal diagnosis was performed for couples whom were both found to be SMA carriers.@*RESULTS@#In total 62 SMA carriers were identified among the 3049 subjects, which yielded a carrier frequency of 1 in 49 (2.03%). No statistical difference was found in the carrier frequency between males and females (1.91% vs. 2.30%, P>0.05). Respectively, 1.3% (41/3049) and 0.69% (21/3049) of the carriers were caused by heterozygous deletion and conversion of the SMN1 gene. The average copy number for SMN1 alleles was 1.99. Two couples were found to be both as SMA carriers, for whom the birth of an affected fetus was avoided by prenatal diagnosis.@*CONCLUSION@#No difference was found in the carrier frequency of SMA-related mutations between the two genders in Yunnan region, which was in keeping to an autosomal recessive inheritance pattern. Determination of the carrier frequency for SMA and SMN gene variants may provide a basis for genetic counseling and prenatal diagnosis for the disease.

Result of Sanger sequencing for newborn carriers of single heterozygous variants of GJB2 or SLC26A4 gene by genechip analysis / 中华医学遗传学杂志

OBJECTIVE@#To detect additional variants for newborn carriers of single heterozygous variants of the GJB2 or SLC26A4 gene by genechip analysis in Changsha area, and explore the variation spectrum of deafness-related genes in this region.@*METHODS@#For 462 newborns carrying single heterozygous variants of the GJB2 or SLC26A4 gene, all exons of the genes were subjected to Sanger sequencing. The pathogenicity of the variants was analyzed by database and literature search.@*RESULTS@#For 305 newborns carrying a heterozygous GJB2 variant, 143 (46.49%) were found to carry additional variants, including 29 (9.51%) with c.109G>A likely pathogenic variant, and 1 (6.48%) with c.551G>A pathogenic variant. Among 153 newborns carrying single heterozygous variant of the SLC26A4 gene, 2 (1.31%) were found with a c.281C>T variant, and 1 (0.65%) with a c.1547_1548ins pathogenic variant. Among 4 newborns simultaneously carrying GJB2 and SLC26A4 variants, two were found to carry c.109G>A and c.844T>C variants (clinical significance unknown), respectively.@*CONCLUSION@#For newborns carrying single heterozygous variants of the GJB2 or SLC26A4 gene by genechip analysis, the detection rate for other variants is quite high. Sanger sequencing can significantly improve the detection rate of high-risk newborns and enrich the variant spectrum of deafness genes.

Herencia conjunta de α+-talasemia y portador de hemoglobina S / Co-inheritance of α+-thalassemia and sickle trait

Resumen En este reporte de caso se describe el primer paciente doble heterocigoto para alfa+-talasemia tipo -3,7 y rasgo heterocigoto por hemoglobina S en Costa Rica, diagnosticado desde su nacimiento por medio del tamizaje neonatal como heterocigoto para hemoglobina S. Luego de la detección de la hemoglobina S por tamizaje, el paciente fue referido al servicio de Hematología del Hospital Nacional de Niños para su seguimiento, en donde se observa hemograma con índices y morfología de glóbulos rojos sugestivos de alfa talasemia, con presentación de electroforesis de hemoglobina con patrón AS cuya expresión relativa de HbS era menor de lo esperado, lo que motivó a efectuar estudio molecular del gen de alfa globina, que confirmó el diagnóstico de alfa talasemia con deleción heterocigota de tipo -3,7 en herencia conjunta con la heterocigosis de hemoglobina S.

Abstract In this case report we describe the first patient compound heterozygous for type -3.7 alpha+ thalassemia and sickle cell trait in Costa Rica, who was diagnosed from birth by neonatal screening as heterozygous for hemoglobin S. After detection of hemoglobin S by screening, the patient was referred to the Hematology service of the National Children`s Hospital for follow-up, where hemogram with indexes and morphology of red blood cells suggestive of alpha thalassemia is observed, presenting hemoglobin electrophoresis with AS pattern whose relative expression of hemoglobin S was lower tan expected, which led to a molecular study of the alpha globin gene confirming the diagnosis of alpha thalassemia with heretozygous deletion of type -3.7, in co-inheritance with hemoglobin S heterozygosis.

A pioneering RET genetic screening study in the State of Ceará, Brazil, evaluating patients with medullary thyroid cancer and at-risk relatives: experience with 247 individuals

ABSTRACT Objective: Initial diagnosis of medullary thyroid carcinoma (MTC) is frequently associated with advanced stages and a poor prognosis. Thus, the need for earlier diagnoses and detection in relatives at risk for the disease has led to increased use of RET genetic screening. Subjects and methods: We performed RET screening in 247 subjects who were referred to the Brazilian Research Consortium for Multiple Endocrine Neoplasia (BRASMEN) Center in the State of Ceará. Direct genetic sequencing was used to analyze exons 8, 10, 11, and 13-16 in MTC index cases and specific exons in at risk relatives. Afterward, clinical follow-up was offered to all the patients with MTC and their affected relatives. Results: RET screening was performed in 60 MTC index patients and 187 at-risk family members. At the initial clinical assessment of the index patients, 54 (90%) were diagnosed with apparently sporadic disease and 6 (10%) diagnosed with hereditary disease. After RET screening, we found that 31 (52%) index patients had sporadic disease, and 29 (48%) had hereditary disease. Regarding at-risk relatives, 73/187 were mutation carriers. Mutations in RET codon 804 and the rare p.M918V mutation were the most prevalent. Conclusions: Performing RET screening in Ceará allowed us to identify a different mutation profile in this region compared with other areas. RET screening also enabled the diagnosis of a significant number of hereditary MTC patients who were initially classified as sporadic disease patients and benefited their relatives, who were unaware of the risks and the consequences of bearing a RET mutation.

Clinical features of carriers of reciprocal chromosomal translocations involving chromosome 2: report of nine cases and review of the literature

ABSTRACT Objective: To explore the clinical features of carriers of chromosome 2 translocations, enabling informed genetic counseling of these patients. Materials and Methods: Eighty-two male carriers of a translocation who were infertile or receiving fertility counseling were recruited. Cytogenetic analyses were performed using G-banding. A search of PubMed was performed to determine whether the identified translocations on chromosome 2 are involved in male infertility. The relationships of translocation breakpoints with male infertility and recurrent pregnancy loss were analyzed. Results: Of the 82 translocation carriers, 9 (11%) were carriers of a chromosome 2 translocation. Four cases had oligozoospermia or infertility, while five had normal semen. In an analysis of the literature, 55 patients who were carriers of chromosome 2 translocations were also reviewed. Breakpoints at 2p13 and 2q31 were observed in six patients each, and were the most common. Breakpoints at 2p23, 2p13, 2p11.2, 2q31, and 2q37 were associated to both pre-gestational and gestational infertility, while other breakpoints were associated with gestational infertility. Conclusions: All breakpoints at chromosome 2 were correlated with gestational infertility. Carriers of chromosome 2 translocations should therefore receive counseling to continue with natural conception and use of different technologies available via assisted reproductive technology, such as preimplantation genetic diagnosis.

Analysis of chromosomes of embryos derived from translocation carriers during preimplantation genetic diagnosis cycles / 中华医学遗传学杂志

OBJECTIVE@#To explore the effect of chromosomal translocations on the composition of embryonic chromosomes and its mechanism.@*METHODS@#For 52 couples with one partner carrying a chromosomal translocation, results of next generation sequencing of all embryos derived from 61 cycles were divided into different groups based on the type of translocations, gender of the carrier, and maternal age. Effect of parental chromosomal translocations on the composition of embryonic chromosomes of each group was analyzed.@*RESULTS@#A significant difference was found between carriers of reciprocal and Robertsonian translocations in terms of proportion of abnormal embryos and structurally normal chromosomes (63.3% vs. 27.5%, and 1.1% vs. 0.3%, respectively). Compared with male carriers, there was an increase in the rate of abnormalities for female carriers (67.2% vs. 58.3% for reciprocal translocations, and 45.5% vs. 13.8% for Robertsonian translocations). The risk for chromosomal abnormality also increased with the maternal age. No significant difference was found in the proportion of abnormal embryos between carriers divided by involvement of acrocentric chromosomes or terminal chromosomal breakpoints.@*CONCLUSION@#The types of parental translocation, gender of carrier, maternal age, and interchromosomal effect have certain effect on the composition of embryonic chromosomes.

Acidúria L2-hidroxiglutárica: circulação do gene em cães da raça Staffordshire Bull Terrier no Brasil em 2008-2015 / L2-hydroxyglutaric aciduria: circulation of the gene in Staffordshire Bull Terrier dogs in Brazil (2008-2015)

O objetivo do trabalho foi identificar a presença no Brasil do gene mutante L2HGDH em cães da raça Staffordshire Bull Terrier (SBT). Para tanto foi feito o teste genético em 76 cães provenientes de diferentes regiões do Brasil, no período de 2008 a 2015, sendo encontrados 55 animais (72,37%) livres do gene mutante L2-HGDH ou homozigotos dominantes, e 21(27,63%) portadores do gene mutante ou heterozigotos. Não foi encontrado nenhum animal homozigoto recessivo (afetado), porém pode-se observar que o gene circula no Brasil e que cães afetados podem aparecer.(AU)

The aim of this study was to identify the presence of a mutation in the L2-hydroxyglutarate dehydrogenase (L2-HGDH) gene in Staffordshire bull terriers in Brazil. Genetic testing was done in 76 dogs from different regions of the country, from 2008 to 2015. Fifty-five dogs (72.37%) were free of the mutant gene L2HGDH or homozygous-dominant, and 21 (27.63%) were carriers for the mutant gene or heterozygous. No homozygous recessive dogs (affected) were found, however, it is worth noting that the gene circulates in Brazil and that affected dogs can appear.(AU)

Evidence of heterozygosity and recombinant alleles in single cysts of Giardia duodenalis / Evidência de heterozigose e alelos recombinantes em cistos individualizados de Giardia duodenalis

Abstract Giardia duodenalis is divided into eight assemblages (named A to H). Isolates of assemblage A are divided into four sub-assemblages (AI, AII, AIII and AIV). While isolates of sub-assemblage AII are almost exclusively detected in human hosts, isolates of assemblage B are encountered in a multitude of animal hosts and humans. Here, we isolated single cysts of G. duodenalis from a human stool sample and found that one of them had overlaps of assemblage AII and B alleles and an unexpectedly high number of variants of the beta-giardin (Bg) and GLORF-C4 (OrfC4) alleles. In addition, one of the Bg alleles of that cyst had a fragment of sub-assemblage AII interspersed with fragments of assemblage B, thus indicating that this allele may be a recombinant between sequences A and B. Our results are unprecedented and put a check on the statement that different assemblages of G. duodenalis represent species with different host specificities.

Resumo A espécie Giardia duodenalis é dividida em oito grupos (nomeados de A a H). Isolados do grupo A são divididos em quatro subgrupos (AI, AII, AIII and AIV). Enquanto isolados do subgrupo AII são detectados quase exclusivamente em hospedeiros humanos, isolados do subgrupo B são encontrados em uma grande variedade de hospedeiros entre animais e humanos. Neste trabalho, foi constatado que, dentre diversos cistos individualizados de G. duodenalis provenientes de fezes de origem humana, um cisto continha os alelos AII e B e um número inesperado de variantes de alelos codificadores de beta giardina e GLORF-C4. Ainda, um dos alelos beta giardina desse cisto possuía fragmentos AII intercalando um fragmento B, indicando que esse alelo pode ser um recombinante entre alelos AII e B. Os resultados aqui apresentados são inéditos e colocam em dúvida o conceito atual de que os diferentes grupos de G. duodenalis representam espécies distintas com diferentes graus de especificidade por hospedeiros.

Asociación entre polimorfismos del gen NAT2 y fisura labiopalatina no sindrómica en Argentina / Association between NAT2 polymorphisms with non-syndromic cleft lip with or without cleft palate in Argentina

Background: NAT genes are considered candidate genes for the genetic predisposition to non-syndromic Cleft lip with or without cleft palate (NSCLP), since they codify for N-acetyltransferases, enzymes responsible for the biotransformation of arylamines, hydrazine drugs, and a great number of toxins and carcinogens present in diet, cigarette smoke, and environment. Aim: To determine the association between alleles determining slow acetylator phenotype and the risk of NSCLP. Material and Methods: We analyzed *5 (481C>T), *6 (590G>A) and *7 (857G>A) alleles which determine the slow acetylator phenotype and *4 (wild type) allele by polymerase chain reaction/restriction fragment length polymorphism in 97 progenitor-case trios of NSCLP in Argentinian Obstetric Wards. We evaluated the transmission disequilibrium (TDT). Results: TDT showed a positive association between allele *5 and NSCLP (odds ratio = 1,6; p = 0,03). Conclusions: The presence of *5 allele is significantly higher in cases with congenital NSCLP.

Preimplantation genetic diagnosis of infantile malignant osteopetrosis in a Chinese family / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To explore the application of preimplantation genetic diagnosis (PGD) for infantile malignant osteopetrosis (IMO).</p><p><b>METHODS</b>For a family affected with IMO, PGD was provided using combined parental mutation detection and haplotype constructions with microsatellite markers spanning the TCIRG1 gene. Prenatal diagnosis was performed on the chorionic villus and amniocentesis samples by direct sequencing.</p><p><b>RESULTS</b>Prenatal diagnosis showed that the fetus by the third pregnancy has carried the parental mutations [c.242delC (p.Pro81Argfs*85) and c.1114C>T (p.Gln372*)], and the pregnancy was terminated. PGD was subsequently performed through mutations detection and haplotype analyses following whole genome amplification (WGA) of each of 13 cells. The results showed that 6 of the 13 embryos were unaffected, 3 were carriers and 4 were affected. Well developed unaffected/carrier embryos were selected and transferred into the uterus. A single pregnancy was confirmed. Subsequently pre- and post-natal diagnoses have confirmed development of a healthy child.</p><p><b>CONCLUSION</b>The study demonstrated the advantage of PGD over prenatal diagnosis when natural pregnancies have repeatedly produced IMO children/fetuses.</p>

Identification of Duchenne muscular dystrophy carrier by detecting junction fragments between the breakpoints of introns / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the value of the junction fragments between the breakpoints of introns in identifying deletional Duchenne muscular dystrophy (DMD) carriers.</p><p><b>METHODS</b>A DMD family (including the index patient III2 and the suspected carrier II3) and a sporadic DMD case (including the patient II1 and his mother I2) were studied. The patient III2 of the DMD family was identified as having exons 31-43 deletion of the DMD gene, and the sporadic patient II1 had exons 45-54 deletion. A PCR-based genome-walking method was used to locate the breakpoints in the corresponding introns. The junction fragments of the patients and their female relatives waiting for a diagnosis were amplified by PCR with primers adjacent to the deletion junctions.</p><p><b>RESULTS</b>PCR amplification yielded identical positive results for the female suspected carrier II3 of and the index patient of the DMD family, and the former was thus diagnosed as a carrier of DMD. PCR amplification of the sporadic patient's mother I2 showed a negative result, but the patient II1 had a positive result, so that the patient's mother was excluded as being a carrier of DMD.</p><p><b>CONCLUSION</b>Routine PCR technique for detecting the junction fragments allows identification of carriers among female relatives of patients with deletional DMD.</p>

Analysis and carrier screening for copy numbers of SMN and NAIP genes in children with spinal muscular atrophy / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To assess the association of copy number variations of SMN1, SMN2, NAIP, GTF2H2 and H4F5 genes with clinical classification of spinal muscular atrophy in children, and determine the copy number of the SMN gene among pregnant women. A carrier screening was also performed in Sichuan province.</p><p><b>METHODS</b>The copy number variations of the above genes among 53 confirmed SMA patients were determined with MLPA technique. The copy number variations were analyzed by the Fisher's exact test. Deletion of exon 7 in the SMN1 gene was screened with denaturing high performance liquid chromatography (DHPLC) for 427 pregnant women.</p><p><b>RESULTS</b>Among the 53 cases of type I, II, and III SMA patients, the rate of homozygous deletion of both exons 7 and 8 of the SMN1 gene were 100%, 94.44% and 87.50%, respectively, whereas those of homozygous deletion of exon 7 of SMN1 gene were 0, 5.56%, and 12.50%, respectively. The patients with 1, 2, 3, and 4 copies of exon 7 of the SMN2 gene were 11.32%, 67.92%, 13.21% and 7.55%, respectively. The patients with 0, 1, and 2 copies of exon 5 of NAIP gene were 11.32%, 62.26%, and 26.42%, respectively. No deletion was detected in GTF2H2 or H4F5 genes. The heterozygous loss rate of exon 7 in SMN gene in the pregnant women population of Sichuan region was approximately 2.11%.</p><p><b>CONCLUSION</b>Copy number variations of SMN2 and NAIP genes in patients are related to SMA clinical types (P < 0.05). In contrast, there was no relationship between SMA clinical types and deletion of exons 7 and 8 in the SMN1 gene (P > 0.05). Analysis of copy number change in SMN1 gene can assist SMA carrier screening. However, when the general population without SMA family history is screened for disease-causing genes, it should be noted that the type "2+0" carriers may affect the screening result, and the result should be interpreted with caution.</p>