Two novel mutations of DAX-1 were detected in 2 unrelated patients with AHC, and complete deletion of DAX-1 in a patient with Xp21 contiguous gene syndrome who also presented with glycerol kinase deficiency, Duchenne muscular dystrophy, and AHC.
Clinical experience has suggested that patients with the contiguous gene syndrome, complex glycerol kinase deficiency (cGKD), will have mental retardation (MR) if they have deletions extending from the GK gene into the DMD gene and/or involving a significant extension telomeric from DAX1.