One patient had a 7.15-Mb contiguous deletion involving the NR0B1, Duchenne muscular dystrophy (DMD), glycerol kinase (GK) and melanoma antigen, family B, 16 (MAGEB16) genes.
Complex glycerol kinase deficiency (GKD) results from the contiguous deletion on Xp21 of all or part of the gene for glycerol kinase together with that for adrenal hypoplasia congenita (AHC) and /or Duchenne muscular dystrophy (DMD).
The complex GKD is an Xp21 contiguous gene syndrome involving the glycerol kinase locus together with the adrenal hypoplasia congenita (AHC) or Duchenne muscular dystrophy (DMD) loci or both.
For example, the map suggests that the adrenal hypoplasia congenita and glycerol kinase genes are physically close to each other, are within 1-2 Mb of the telomeric end of the Duchenne muscular dystrophy (DMD) gene, and are nearer to the DMD locus than to the more distal marker DXS28 (C7).
The result of the present study and results of previous studies suggest that genes for ornithine transcarbamylase (OTC), DMD, and GK and putative genes responsible for congenital adrenal hypoplasia (AHC) and GTD are arranged from telomere to centromere as pter--GTD--AHC--GK--DMD--OTC--cen.