X-linked myotubular myopathy due to a complex rearrangement involving a duplication of MTM1 exon 10

X-linked myotubular myopathy is a predominantly severe congenital myopathy with central nuclei on muscle biopsy due to mutations in the MTM1 gene encoding myotubularin. We report a boy with typical features of X-linked myotubular myopathy. Sequencing of the MTM1 gene did not reveal any causative mutations. Subsequent MLPA analysis identified a duplication of MTM1 exon 10 both in the patient and his mother. Additional quantitative fluorescent PCR and long-range PCR revealed an additional large deletion (2536 bp) within intron 10, 143 bp downstream of exon 10, and confirmed the duplication of exon 10. Our findings suggest that complex rearrangements have to be considered in typically affected males with X-linked myotubular myopathy. (C) 2011 Elsevier B.V. All rights reserved

Clomiphene and hypospadias on a detailed level: Signal or chance?

BACKGROUND: Clomiphene, a drug used to induce ovulation, is chemically related to diethylstilbestrol. (IDES). DES is associated with vaginal cancer and infertility among daughters and with hypospadias among second-generation male offspring. Because clomiphene has a long half-life and metabolites have been found in feces up to 6 weeks after administration, fetal exposure is possible if the mother took this drug prior to becoming pregnant. METHODS: Case-control analyses were performed to investigate the association between clomiphene exposure and hypospadias. Cases were all male subjects registered in the European Concerted Action on Congenital Anomalies and Twins (EUROCAT) Northern Netherlands registry for congenital anomalies with nonsyndromal hypospadias. Controls were all male children born without hypospadias, including those with chromosomal and monogenic defects. Logistic regression analyses were performed to calculate odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: Of 392 cases, 7 (1.8%) were exposed to clomiphene compared with 64 of 4538 controls (1.4%). For penoscrotal hypospadias, we found that the OR was significantly increased (6.08; 95% CI, 1.40-26.33); for the mild and moderate forms of hypospadias, the ORs were not increased. CONCLUSIONS: Because penoscrotal hypospadias is rare, the effect is diluted when all forms of hypospadias are studied as a group. Therefore, our study stresses the importance of studying birth defects on as detailed a level as possible. Other studies should be conducted to confirm our findings. Birth Defects Research (Part A) 76:249-252, 2006. (c) 2006 Wiley-Liss, Inc

The Common ABCA4 Variant p.Asn1868Ile Shows Nonpenetrance and Variable Expression of Stargardt Disease When Present in trans With Severe Variants

Contains fulltext : 194515.pdf (Publisher’s version ) (Open Access

Diagnostic exome sequencing in 266 Dutch patients with visual impairment

Contains fulltext : 174726.pdf (publisher's version ) (Open Access)Inherited eye disorders have a large clinical and genetic heterogeneity, which makes genetic diagnosis cumbersome. An exome-sequencing approach was developed in which data analysis was divided into two steps: the vision gene panel and exome analysis. In the vision gene panel analysis, variants in genes known to cause inherited eye disorders were assessed for pathogenicity. If no causative variants were detected and when the patient consented, the entire exome data was analyzed. A total of 266 Dutch patients with different types of inherited eye disorders, including inherited retinal dystrophies, cataract, developmental eye disorders and optic atrophy, were investigated. In the vision gene panel analysis (likely), causative variants were detected in 49% and in the exome analysis in an additional 2% of the patients. The highest detection rate of (likely) causative variants was in patients with inherited retinal dystrophies, for instance a yield of 63% in patients with retinitis pigmentosa. In patients with developmental eye defects, cataract and optic atrophy, the detection rate was 50, 33 and 17%, respectively. An exome-sequencing approach enables a genetic diagnosis in patients with different types of inherited eye disorders using one test. The exome approach has the same detection rate as targeted panel sequencing tests, but offers a number of advantages. For instance, the vision gene panel can be frequently and easily updated with additional (novel) eye disorder genes. Determination of the genetic diagnosis improved the clinical diagnosis, regarding the assessment of the inheritance pattern as well as future disease perspective