Karyotyping and analysis of 5α -reductase-2 gene mutation in 25 patients with hypospadias / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To analyze the karyotypes and SRD5A2 gene mutations in 25 patients with sporadic or familial hypospadias.</p><p><b>METHODS</b>The patients included 10 adults and 15 children, whose chromosomes were analyzed by G-banded karyotyping, and the SRD5A2 genes were sequenced.</p><p><b>RESULTS</b>Two patients were found to have an abnormal karyotype, while eight have carried compound heterozygous mutations of the SRD5A2 gene, which included 5 genotypes formed by 6 types of mutations, i.e., p.G203S/p.R227Q, p.R227Q/p.R246Q, p.Q6X/p.Q71X, p.L20P/p.G203S, and p.Q71X/p.R227Q. Mutations of the SRD5A2 gene were present in 32% (8/25) of all patients, 35% (8/23) in those with a normal karyotype, and 44.4% (8/18) in those with proximal type hypospadia. Bioinformatic analysis, literature review and pedigree analysis confirmed that all such mutations are pathogenic.</p><p><b>CONCLUSION</b>Chromosomal anomalies and mutations of the SRD5A2 gene are the main cause of hypospadias. Sequencing of the SRD5A2 gene may explain the etiology of nearly half of the patients with proximal type of hypospadas but a normal karyotype, which can facilitate genetic consulting.</p>

Analysis of FOXL2 gene mutations in 5 families affected with blepharophimosis, ptosis and epicanthus inversus syndrome / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To screen for FOXL2 gene mutations in 6 patients with blepharophimosis, ptosis, and epicanthus inversus syndrome (BPES), and explore their genotype-phenotype correlation.</p><p><b>METHODS</b>Peripheral venous blood samples were collected from the patients for the extraction of genomic DNA. PCR and Sanger sequencing were employed to analyze the coding region and flanking sequences of the FOXL2 gene. Pathogenicity of the identified mutations was verified through literature review and bioinformatic analysis.</p><p><b>RESULTS</b>A heterozygous c.672_701dup30 mutation was found in the probands from the two familial cases, while three heterozygous mutations (two were novel), namely c.462_468del (p.Pro156Argfs*113), c.251T to A (p.Ile84Asn) and c.988_989insG (p.Ala330Glyfs*204) were detected in the three sporadic cases. Literature review and bioinformatic analysis indicated that all these mutations are pathogenic.</p><p><b>CONCLUSION</b>Identification of causative mutations in the BPES patients has provided a basis for genetic counseling and reproductive guidance. The novel mutations have enriched the mutation spectrum of the FOXL2 gene.</p>