Mutations in the arylsulfatase E gene, located on the X chromosome, have been shown to cause chondrodysplasia punctata (CDP). A substitution of arginine with serine at amino acid 12 (R12S) was identified in a patient with typical features of mild symmetrical CDP including mild mental retardation. The proband was institutionalized and was found to have seven full and half siblings all of whom were microcephalic. Six siblings are alive and all are mentally retarded. The mother is borderline retarded. The mother and three daughters are carriers of the R12S change, but do not appear to have CDP. A son and three other daughters do not carry the R12S change. Further studies revealed that the mother had phenylketonuria (PKU) and the children maternal PKU. This suggests that the R12S change is not the primary cause of short stature, microcephaly, and mental retardation in this family. The relationship between CDP and PKU, both of which can cause short statue and mental retardation, is discussed.
Copyright 1999 Academic Press.