Prenatal diagnosis of Duchenne/Becker muscular dystrophy by short tandem repeat segregation analysis in Argentine families

Abstract

Introduction: Duchenne/Becker muscular dystrophies (DMD/BMD) are X-linked recessive diseases caused by mutations in the dystrophin gene.

Methods: We used multiplex polymerase chain reaction (PCR) and short tandem repeat (STR) segregation analysis for DMD/BMD-carrier detection and prenatal diagnosis.

Results: Twenty-four at-risk pregnancies were evaluated: 17 were excluded from carrying dystrophin gene mutations with 95-100% certainty. Of the remaining cases, 2 were determined to carry a dystrophin gene mutation with 95-100% certainty. Three cases had a 67% probability of carrying the mutation, and 2 others were not informative. The certainty of the test increased to ~100% in some cases due to the identification of several genetic events: 4 recombinations; 4 de novo mutations; and 8 deletions encompassing some of the STRs evaluated.

Discussion: 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.