A novel deletion of the dystrophin S-promoter region cosegregating with mental retardation

A contiguous deletion of the S-promoter/first S exon and its downstream exo n 56 of the dystrophin gene was identified in a Japanese dystrophinopathy f amily in which two brothers and their half brother were affected. Character istically, severe mental retardation cosegregated with the deletion even th ough they grew up in different environments. Furthermore, mild cerebral atr ophy was observed by CT scan and MRI in the eldest brother.