Efficiency of multiplex ligation-dependent probe amplification combined with short tandem repeat linkage analysis for the prenatal diagnosis for Duchenne muscular dystrophy / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate the efficiency of multiplex ligation-dependent probe amplification (MLPA) combined with short tandem repeat (STR) linkage analysis for the prenatal diagnosis for Duchenne muscular dystrophy (DMD).</p><p><b>METHODS</b>Gender of the fetus was first determined by the presence of Y chromosome sex-determining gene (SRY). Subsequently, combined MLPA and STR linkage analysis were applied for the probands, pregnant women and fetuses in 45 affected families.</p><p><b>RESULTS</b>Among the 45 families, 31 SRY-positive fetuses were identified, among whom six were diagnosed with DMD. For 14 SRY-negative fetuses, four were diagnosed as carriers. The remainders were normal.</p><p><b>CONCLUSION</b>MLPA can detect mutations in the exons of dystrophin gene, whilst STR linkage analysis can determine whether the fetus has inherited the maternal X chromosome bearing the mutant gene. As the result, the method can detect affected fetuses in which no exonic mutations are detected with MLPA. By combining the two methods, the diagnostic rate for DMD can be greatly improved.</p>

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>

Analysis of CYP17A1 gene mutation in a child patient with 17 alpha-hydroxylase/17, 20-lyase deficiency / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To analyze CYP17A1 gene mutations in a child patient with 17 alpha-hydroxylase/17, 20-lyase deficiency (17OHD), and to review characteristics of CYP17A1 gene mutations in Chinese patients with 17OHD.</p><p><b>METHODS</b>Clinical data were collected. PCR and DNA sequencing were performed to detect mutations in the patient.</p><p><b>RESULTS</b>The patient has presented classical features of 17OHD including hypertension, hypokalemia, decreased sex hormones and plasma cortisol, and elevated blood adrenocorticotrophic hormone. A compound heterozygous mutation c.987C>A and c.985del was detected in the CYP17A1 gene, which resulted in two premature stop codons at positions 328 and 417.</p><p><b>CONCLUSION</b>A compound mutation, c.987C>A and c.985del, has been identified in a patient with 17OHD. Among CYP17A1 gene mutations identified in Chinese patients, missence mutations have been most common, and exons 5 and 8 have been the mutation hotspots.</p>

Genetic variation of 9 X-linked short tandem repeat loci among four populations of Inner Mongolian / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate the genetic structure of X chromosome in Mongolia, Ewenki, Elunchun and Dawoer in Inner Mongolia.</p><p><b>METHODS</b>Nine short tandem repeat (STR) markers on the X chromosome (DXS6789, DXS101, DXS8378, DXS7132, DXS7133, DXS7423, DXS6804, DXS6799 and HPRTB) were analyzed in the four populations from Inner Mongolian (Mongol, Ewenki,Oroqen and Daur) for their genetic diversity, forensic suitability and possible genetic affinities of the populations. Frequencies and other parameters of forensic interest were computed.</p><p><b>RESULTS</b>The results revealed that the nine markers described here have a moderate degree of variability in the population groups. And there are significant differences in the genetic variability among the populations. Genetic distance and cluster analyses show very low genetic distance between Mongol and Han (Xi'an) communities. The results based on genetic distance analyses are consistent with earlier studies based on linguistic as well as immigration history and origin of these populations.</p><p><b>CONCLUSION</b>The nine STR loci studied here were found not only useful in studying genetic variations between populations but also suitable for human identity testing.</p>

Genetic structure of X-STR loci of Ewenki nationality and its affinity with other nationalities / 中南大学学报(医学版)

OBJECTIVE@#To determine the genetic diversity of X-TR loci, and to evaluate the genetic structure X chromosome's of Ewenki nationality and its affinity with other nationalities.@*METHODS@#We chose 9 X-TR (DXS6804, DXS7133, DXS101, DXS6789, DXS6799, DXS7423, HPRTB, DXS8378, DXS7132) as genetic markers from 99 irrelative individules to determine the genetic diversity of Ewenki in Inner Mongolian. Cluster analysis and phylogenic trees was applied to show the genetic distance among the nationalities.@*RESULTS@#We got 51 alleles in the studied population, with the frequency diverse between 0.0109 and 0.6863. Genotype frequency was from 0.0217 to 0.3778. Heterozygosity(H),the power of discrimination(PD) and the polymorphism information conten (PIC) were consistent with the forensic application. Cluster analysis and phylogenic trees revealed that Ewenki nationality had estrangement genetic affinity with the other 3 major nationalities in inner mongolia and Han nationality in Xi'an.@*CONCLUSION@#The genetic information demonstrates that the 9 chosen gene makers were highly informative loci and are suitable for population genetics research and forensic application.