Clinical phenotype and genetic analysis of twelve children with ring chromosomes / 中华医学遗传学杂志

OBJECTIVE@#To explore the prevalence and clinical manifestations of ring chromosomes among children featuring abnormal development.@*METHODS@#From January 2015 to August 2021, 7574 children referred for abnormal development were selected, and their peripheral blood samples were subjected to G-banded chromosomal karyotyping analysis.@*RESULTS@#Twelve cases of ring chromosomes were detected, which have yielded a prevalence of 0.16% and included 1 r(6), 2 r(9), 1 r(13), 1 r(14), 2 r(15), 1 r(21) and 3 r(X). The children had various clinical manifestations including growth and mental retardation, limb malformation, and congenital heart disease. For two children with r(9) and two with r(15) with similar breakpoints, one child with r(9) and one with r(15) only had growth retardation, whilst another with r(9) and another with r(15) also had peculiar facies and complex congenital heart disease. The r(X) has featured some manifestations of Turner syndrome.@*CONCLUSION@#Ring chromosomes are among the common causes for severe growth and mental retardation in children with diverse clinical phenotypes. Clinicians should pay attention to those with developmental anomalies and use chromosomal analysis to elucidate their genetic etiology.

Application value of CNV-seq for the prenatal diagnosis of women with high-risk pregnancies / 中华医学遗传学杂志

OBJECTIVE@#To assess the application value of copy number variation sequencing (CNV-seq) for women with a high risk for fetal anomalies.@*METHODS@#Based on the results of non-invasive prenatal testing (NIPT), 271 high-risk pregnant women were divided into NIPT positive group (n = 83) and other anomaly group (advanced age, high risk by serological screening, repeated NIPT failure, adverse pregnancy history, abnormal ultrasound finding, and abnormal phenotype) (n = 188). CNV-seq was carried out to detect copy number variations (CNVs) in amniocytic DNA from the two groups of pregnant women, and karyotyping analysis of the amniotic cells was carried out for verification and comparison.@*RESULTS@#The amniocytes from 271 pregnant women were detected. The detection rate was 20.66% (56/271) for pathogenic CNVs by CNV-seq and 19.19% (52/271) for pathogenic karyotypes by karyotyping analysis. The difference was statistically significant (P < 0.05). CNV-seq had shown that, compared with NIPT positive group, the detection rates for likely pathogenic CNVs and variants of unknown significance (VUS) in other abnormality group were significantly higher [2.41%(2/83) vs. 5.32%(10/188)](P < 0.05).@*CONCLUSION@#CNV-seq can well suit the first-tier diagnosis for pregnant women suspected for fetal abnormality. In prenatal diagnosis settings, CNV-seq can identify additional and clinically significant cytogenetic abnormalities. In those with other abnormalities, the detection rates for likely pathogenic CNVs and VUS are higher than with the NIPT positive cases.

Cytogenetic analysis on 5329 children in genetic counseling / 实用医学杂志

Objective To explore the relationship between chromosomal abnormalities and diseases in children by analyzing chromosome karyotypes. Methods The chromosome karyotype analysis of peripheral lymphocytes in 5 329 children was performed. Results In all, abnormal karyotype were found in 1 723 cases (32.33％) , in which the numerical chromosome abnormalities were detected in 1 539 (89.32％) , following by 125 cases of structural chromosome abnormalities (7.25％) , 53 cases of sex reverse syndrome (3.08％) , and 6 cases of true hermaphroditism (0.35％). The chromosome polymorphism were detected in 228 cases (4.28％). Conclusions The numerical chromosome abnormalities is most frequent chromosomal aberration and is one of the important causes that result in mental retardation, growth delay and disorders of sex development in children.

Analysis of the Mutations in SLC26A4 Gene in Children with Non-syndromic Hearing Loss / 听力学及言语疾病杂志

Objective To study the SLC26A4 mutations in children with non -syndromic hearing loss by ge-netic testing method ,for the purpose of investigating etiology and mutation regularity of hearing loss ,and to provide basic information for the molecular diagnosis of hearing loss .Methods Blood samples and clinical data of 137 spo-radic cases with non -syndromic hearing loss and 126 normal controls were collected .The SLC26A4 gene of the pa-tients and normal controls were amplified by polymerase chain reaction (PCR) ,then subjected to automatic DNA se-quencing .Results Pathologic SLC26A4 mutations were identified in 23 out of 137 patients ,and in 23 out of 119 bi-lateral deafness ,mutate rate were 16 .79% and 19 .33% ,respectively .SLC26A4 mutations were identified in 19 out of 20(95% ) patients with bilateral LVA .A total of 11 mutations were identified in the present study ,including 4 novel mutations (E29K(c .85G>A) ,R79X(c .235C> T) ,C282G(c .844T>G) ,V285I(c .853G>A) )and 7 repor-ted mutations .In the present study ,IVS7-2A>G was the most common mutation ,and was detected in 19 out of 23(82 .61% ) patients with SLC26A4 mutations .Conclusion SLC26A4 mutations ,the common reason for non -syndromic hearing loss ,were closely related with LVA .IVS7-2A>G was the most common mutation in SLC26A4 mutant .

Tumor necrosis factor-? gene polymorphism in obese patients with type 2 diabetes mellitus / 中华内分泌代谢杂志

CT and TT genotype frequencies of TNF-? gene at -857 site in obese patients with type 2 diabetes mellitus (DM)andcontrolgroupswithoutobesity were 0.396, 0.020 and 0.179, 0.000, and T allele 0.220 and 0.090, respectively. This finding suggests that mutation is associated with type 2 DM in obese subjects.