Characterization of mutations in 22 females with X-linked dominant chondrodysplasia punctata (Happle syndrome).

Purpose: Human X-linked dominant chondrodysplasia punctata (CDPX2) or Happle syndrome is associated with mutations in the human emopamil binding protein (EBP), a delta8-delta7-sterol isomerase involved in cholesterol biosynthesis. The purpose of the current study was to determine the spectrum of EBP mutations in females with CDPX2 and the utility of biochemical screening for the disorder by analysis of plasma sterols.

Methods: Genomic sequencing of the coding exons of the human delta8-delta7-sterol isomerase gene was performed on DNA from 26 females with suspected X-linked dominant chondrodysplasia punctata.

Characterization of mutations in fifty North American patients with X-linked myotubular myopathy.

X-linked myotubular myopathy (MTM1) is a rare developmental disorder of skeletal muscle that is characterized by the presence of abnormal central nuclei in biopsy specimens taken from affected individuals. To date 133 different mutations have been identified in the MTM1 gene worldwide. We report here mutations detected in 50 additional U.