Chromosomal microarray analysis of 17 patients with unbalanced reciprocal translocations / 中华医学遗传学杂志

OBJECTIVE@#To retrospectively analyze the results of chromosomal microarray analysis (CMA) and parental origins of unbalanced translocations among 17 patients, so as to provide reference for their genetic counseling.@*METHODS@#The results of CMA for 7 001 samples tested in Chengdu Women and Children's Central Hospital from January 2019 to January 2022 were retrospectively reviewed. Unbalanced reciprocal translocation was defined as two non-homologous chromosomes with lost and gained segments respectively or both with gained segments, and their parental origins were identified by parental chromosomal karyotyping and/or fluorescence in situ hybridization (FISH).@*RESULTS@#In total 17 unbalanced translocations were identified. In three cases, two non-homologous chromosomes both had gained segments, which constituted a derivative chromosome, with the total number of chromosomes being 47. In the remaining 14 cases, there was a terminal deletion on one chromosome and a terminal duplication on the other, 10 of which were confirmed by karyotyping, with the total number of chromosomes being 46. In the derivative chromosome, the lost segment was replaced by a gained segment from another chromosome. Among 15 cases undergoing parental origin analysis, 12 had paternal or maternal chromosomal abnormalities, including 11 balanced translocations and 1 unbalanced translocation. The unbalanced gametes therefore may form through meiosis. In 3 cases, the parental chromosomes were normal, indicating a de novo origin.@*CONCLUSION@#Discovery of terminal duplication and deletion or gained segments on two non-homologous chromosomes by CMA is suggestive of parental balanced translocation, which can facilitate genetic counseling and assessment the recurrence risk for subsequent pregnancies.

Genetic analysis and prenatal diagnosis for ten families affected with tuberous sclerosis complex / 中华医学遗传学杂志

OBJECTIVE To provide prenatal diagnosis for families affected with tuberous sclerosis complex and explore the correlation between phenotype and genotype. METHODS For probands from 10 families, all exons and splicing regions of the TSC1 and TSC2 genes were analyzed with high throughput DNA sequencing. Suspected mutations were verified by Sanger sequencing. RESULTS All probands were found to have mutations, which included 1 case with TSC1 mutation and 9 cases with TSC2 mutations (missense mutations in 6, nonsense mutations in 2, and frameshifting mutation in 1 case). Prenatal diagnosis was provided for 9 cases, and 1 fetus was found to carry a mutation. Genetic analysis has identified a novel pathogenic mutation (TSC2 c.2415-2416 ins GT). CONCLUSION Identification of pathological mutations for tuberous sclerosis complex can facilitate genetic counseling and prenatal diagnosis for the affected families.

Analysis of 12 patients with novel mutations of Dystrophin gene / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To study the characteristics, location, and amino acid changes of novel mutations of the Dystrophin gene.</p><p><b>METHODS</b>Twelve patients in whom no deletion or duplication of the Dystrophin gene was detected were analyzed with next-generation sequencing. Fifty healthy adult males were recruited as the controls.</p><p><b>RESULTS</b>All patients were detected with mutations of the Dystrophin gene, which included c.33C>G, c.583C>T, c.1333C>T, c.2593C>T, c.5731A>T, c.7288G>T, c.2803+1G>T, c.10034G>A, c.4289A>G, c.1905_906delAG, c.5017delC, c.5768_5771delAAGA, and c.6261_6262insA. No similar mutations were found among the controls.</p><p><b>CONCLUSION</b>Our data has enriched the mutation spectrum of the Dystrophin gene and may provide an important basis for genetic diagnosis.</p>

siRNAs interference exogenous GFP gene expression in neuro-2a cells / 中国病理生理杂志

AIM: To assess the effect of RNAi on suppressing the exogenous reporter gene expression in mammalian neurons,and explore the effect of siRNA quantitation on interference efficiency.METHODS: Exogenous green fluorescent protein(GFP) expression vector was transferred into neuro-2a cells,and then the small interference RNA targeting GFP mRNA(siGFP) synthesized by transcription in vitro at three different concentration was used in this experiment.RESULTS: The results showed that the neuro-2a cells can be transfected efficiently and siGFP can inhibit GFP expression greatly.CONCLUSION: RNAi can be applied into mammalian neurons successfully.The research on siRNA quantitation will provide technique support for studying the gene function of neurons in the future.