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>

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>