We report a Becker muscular dystrophy (BMD) family with one 5-year-old affected patient and a 69-year-old asymptomatic grandfather. Dystrophin gene multiplex polymerase chain reaction and multiplex ligation-dependant probe amplification analysis showed that both males carried an in-frame deletion of exons 45-55. Segregation analysis revealed two additional asymptomatic boys in this family. Our finding supports previous predictions that exons 45-55 are the optimal multiexon skipping target in antisense gene therapy to transform the severe Duchenne muscular dystrophy into the milder BMD, or even asymptomatic, phenotype.

Mutations in the GJB2 gene are responsible for more than half of all cases of recessive non-syndromic deafness. This article presents a mutation analysis of the GJB2, GJB6, OTOF and MTRNR1 genes in 252 patients with sensorineural non-syndromic hearing loss. Thirty-one different mutations were identified in GJB2 and GJB6 in 86 of the 252 (34%) patients. We describe for the first time two new mutations in GJB2: the missense mutation c.29 T>C (p.Leu10Pro) in the N terminal domain and c.326 G>T (p.Gly109Val) in the intracytoplasmic domain of connexin 26. This work shows the high prevalence of GJB2 mutations in the Argentinean population, with frequencies that are comparable to those of the Mediterranean area. Most important, it adds two novel GJB2 mutations to be taken into consideration in the genetic diagnosis of non-syndromic sensorineural hearing loss.

Overall, 19 of 24 (79%) molecular prenatal diagnoses were informative, indicating that multiplex PCR/STR segregation analysis is a reliable method for carrier detection and prenatal diagnosis when other more sophisticated techniques are unavailable.