EXCLUSION OF THE EXPANSION OF CAG CTG REPEATS AT 13 LOCI ON CHROMOSOME-12 AS A CANDIDATE GENETIC MUTATION IN SCAPULOPERONEAL SPINAL MUSCULAR-ATROPHY WITH ANTICIPATION/

Scapuloperoneal spinal muscular atrophy (SPSMA) is a neuromuscular dis order characterized by weakness in the distribution of shoulder girdle and peroneal muscles. We have previously described a large New Englan d kindred with autosomal dominant SPSMA and have subsequently linked t his family trait to 12q24.1-q24.31. In this family, disease expression becomes more severe and progressive in successive generations, sugges ting genetic anticipation. Accordingly, we have investigated the thirt een known CAG/CTG repeat loci on chromosome 12 that could be tested by using the polymerase chain reaction as candidate genetic mutations in SPSMA. None of these loci is expanded.