Detection and prenatal diagnosis for RS1 gene mutations in two Chinese families with X-linked juvenile retinoschisis / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To identify potential mutations of retinoschisis 1 (RS1) gene responsible for X-linked retinoschisis (XLRS) in two Chinese families.</p><p><b>METHODS</b>The 6 exons and flanking intronic regions were analyzed with PCR and direct sequencing.</p><p><b>RESULTS</b>Two RS1 mutations were identified in the two families, which included 1 frameshift mutation (c.573delG, p.Pro192fs) and 1 missense mutation (c.626G>A, p.Arg209His).</p><p><b>CONCLUSION</b>Two RS1 mutations have been identified, among which Pro192fs mutation is discovered for the first time in Chinese population. Above results may enrich our understanding of the clinical manifestations of XLRS and facilitated early diagnosis and genetic counseling for the disease.</p>

Significance of detecting free DNA from maternal plasma for the diagnosis of fetal chromosomal aneuploidies / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To determine the feasibility and accuracy of detecting numerical chromosomal abnormalities by high-flux sequencing analysis of free fetal DNA from maternal plasma.</p><p><b>METHODS</b>High-flux sequencing was applied to analyze fetal chromosome sequence copy numbers in 153 pregnant women. Fetal karyotyping was also carried out on amniocentesis samples.</p><p><b>RESULTS</b>Six cases were detected with fetal chromosomal abnormalities by high-flux sequencing analysis, among which five were confirmed by karyotyping to be chromosomal aneuploidies (47,XYY; 45,X; 47,XY,+18; 47,XY,+21 and 47,XY,+13), 1 case was confirmed to be structural rearrangement, i.e., 46,XY,der(13;21)(q10;q10),+21. Furthermore, 3 chromosomal polymorphisms (one 46,XY,21p+ and two 46,XY,Yqh-) were identified. The two methods yielded similar results on fetal chromosome copy number detection.</p><p><b>CONCLUSION</b>High-flux sequencing analysis of free DNA derived from maternal plasma is efficient for detecting fetal chromosomal aneuploidies, and is non-invasive, highly sensitive and specific. It therefore has a broad application in antenatal diagnosis.</p>