Molecular basis of non-syndromic hypospadias: systematic mutation screening and genome-wide copy-number analysis of 62 patients.

STUDY QUESTION: What percentage of cases with non-syndromic hypospadias can be ascribed to mutations in known causative/candidate/susceptibility genes or submicroscopic copy-number variations (CNVs) in the genome? SUMMARY ANSWER: Monogenic and digenic mutations in known causative genes and cryptic CNVs account for >10% of cases with non-syndromic hypospadias. While known susceptibility polymorphisms appear to play a minor role in the development of this condition, further studies are required to validate this observation. WHAT IS KNOWN ALREADY: Fifteen causative, three candidate, and 14 susceptible genes, and a few submicroscopic CNVs have been implicated in non-syndromic hypospadias. STUDY DESIGN, SIZE, DURATION: Systematic mutation screening and genome-wide copy-number analysis of 62 patients. PARTICIPANTS/MATERIALS, SETTING, METHODS: The study group consisted of 57 Japanese and five Vietnamese patients with non-syndromic hypospadias. Systematic mutation screening was performed for 25 known causative/candidate/susceptibility genes using a next-generation sequencer. Functional consequences of nucleotide alterations were assessed by in silico assays. The frequencies of polymorphisms in the patient group were compared with those in the male general population. CNVs were analyzed by array-based comparative genomic hybridization and characterized by fluorescence in situ hybridization. MAIN RESULTS AND THE ROLE OF CHANCE: Seven of 62 patients with anterior or posterior hypospadias carried putative pathogenic mutations, such as hemizygous mutations in AR, a heterozygous mutation in BNC2, and homozygous mutations in SRD5A2 and HSD3B2. Two of the seven patients had mutations in multiple genes. We did not find any rare polymorphisms that were abundant specifically in the patient group. One patient carried mosaic dicentric Y chromosome. LIMITATIONS, REASONS FOR CAUTION: The patient group consisted solely of Japanese and Vietnamese individuals and clinical and hormonal information of the patients remained rather fragmentary. In addition, mutation analysis focused on protein-altering substitutions. WIDER IMPLICATIONS OF THE FINDINGS: Our data provide evidence that pathogenic mutations can underlie both mild and severe hypospadias and that HSD3B2 mutations cause non-syndromic hypospadias as a sole clinical manifestation. Most importantly, this is the first report documenting possible oligogenicity of non-syndromic hypospadias. STUDY FUNDING/COMPETING INTERESTS: This study was funded by the Grant-in-Aid from the Ministry of Education, Culture, Sports, Science and Technology; by the Grant-in-Aid from the Japan Society for the Promotion of Science; by the Grants from the Ministry of Health, Labour and Welfare, from the National Center for Child Health and Development and from the Takeda Foundation. The authors have no competing interests to disclose. TRIAL REGISTRATION NUMBER: Not applicable.

A complete deficiency of coagulation factor XIII A-subunit due to a novel compound heterozygote of Ser 413 Leu missense and an nt 389 (ins G) frameshift mutation.

Coagulation factor XIII consists of two A- and two B-subunits, and either gene mutation can cause a complete deficiency. In a newborn patient with persistent bleeding from the umbilical cord stump, the plasma A-subunit protein was not detectable. Direct PCR sequencing revealed an nt 389 (ins G) frameshift mutation in exon 4 resulting in a new stop codon and a Ser 413 Leu missense mutation in exon 10 in either allele. His mother and father were heterozygous for the nt 389 (ins G) and the Ser 413 Leu, respectively, with about 50% reduction of the plasma A-subunit proteins. In all family members examined only those with either mutation showed the reduced subunit A protein levels. Thus, this complete deficiency of factor XIII was due to a novel compound heterozygous mutation in the A-subunit gene.

Synthesis and antiviral activity of 6-chloropurine arabinoside and its 2'-deoxy-2'-fluoro derivative.

6-Chloropurine arabinoside (3a) was obtained by treatment of the 2'-O-acetylated congener (2) with ammonia in methanol. The 3',5'-di-O-tritylated riboside (6) was allowed to react with diethylaminosulfur trifluoride (DAST) in the presence of pyridine to give the 2'-deoxy-2'-fluoroarabinoside (7), from which 6-chloro-9-(2-deoxy-2-fluoro-beta-D-arabinofuranosyl)purine (3b) was obtained. The antiviral effects of 3a and 3b were assayed against several DNA and RNA viruses. Only 3a displayed potent activity against varicella-zoster virus (VZV). This antiviral activity was dependent on phosphorylation by the VZV-induced thymidine kinase (TK). Compound 3a showed moderate activity against other DNA viruses, herpes simplex type 1 (HSV-1) and type 2 (HSV-2), and vaccinia virus. They were equally active against TK- and TK+ strains of HSV-1, which suggests that the HSV-1-encoded TK does not play a role in the anti-HSV-1 activity. No activity was noted with any of the compounds against various RNA viruses, including human immunodeficiency virus, at subtoxic concentrations.

Evidence for the existence of cytoskeleton-bound polysomes in plants.

When conventional, high ionic strength buffers were used for the isolation of polysomes from pea plants, less than 20% were retained in the detergent-insoluble pellet. Reducing Tris, K+ and Mg++ to 10 mM increased retention to 70%, and when a new, microfilament-stabilizing buffer was used, retention increased to 80%. Conditions which favoured polysome pelleting at lower g forces permitted the retention of actin in the pellet. The data are consistent with the hypothesis that higher plants, like animals, contain cytoskeleton-(actin)-bound polysomes.