DYSTROPHINOPATHY IN A YOUNG BOY WITH KLINEFELTERS-SYNDROME

We report the first case of a child with mild dystrophinopathy associa ted with Klinefelter's syndrome (karyotype 47, XXY). This 3.5-year-old boy was affected by some symptoms suggestive of Becker's muscular dys trophy. Dystrophin immunostaining and immunoblotting procedures confir med the diagnosis, but polymerase chain reaction-directed gene analysi s failed to reveal any macrodeletion. Methylation-based assay did not show preferential X-inactivation. This confirmed the coexistence of th e two active X-chromosomes tone of which was of paternal origin), thus accounting for the mild form of dystrophinopathy in this child affect ed by Klinefelter's syndrome. (C) 1998 John Wiley & Sons, Inc.