OCCURRENCE OF 2 DIFFERENT INTRAGENIC DELETIONS IN 2 MALE RELATIVES AFFECTED WITH DUCHENNE MUSCULAR-DYSTROPHY

The occurrence of 2 different intragenic deletions (exons 10-44 and ex on 45, respectively) is reported in 2 male relatives affected with Duc henne muscular dystrophy, both showing the same haplotype for DNA mark ers not included in the deleted segment. The 2 different deletions see m to have occurred independently in the same X chromosome. This findin g, together with other reports, suggests possibly an increased predisp osition to mutations within the DMD locus in some families. Therefore, when dealing with prenatal diagnosis, the investigation on fetal DNA cannot be restricted only to the region in which a mutation was previo usly identified in the family. (C) 1994 Wiley-Liss, Inc.