Characterisation of a Xp21 microdeletion syndrome in a 2-year-old boy with muscular dystrophy, glycerol kinase deficiency and adrenal hypoplasia congenita.

We report a 2-year-old boy with Duchenne muscular dystrophy (DMD), glycerol kinase deficiency (GK) and adrenal hypoplasia congenita (AHC). At three weeks of age, the patient was hospitalized for the first time with symptoms of hypotone dehydration because of AHC. At present, he shows severe muscular hypotonia and developmental delay. The patient and his family were referred to us for prenatal diagnosis and carrier testing in the mother of the patient and the mother's sister, respectively. The patient's DNA was examined by Southern blot and polymerase chain reaction analyses, using cDNA and genomic probes within and around the dystrophin (DYS) locus. A deletion was revealed, spanning DXS28, the whole dystrophin locus, DXS84 and DXS148, whereas DXS67, DXS68 (pter) and OTC (cen) were found to be retained. The cytogenetically visible microdeletion was also seen in the patient's mother, but not in the mother's sister or the patient's maternal grandmother. Our findings support the locus order pter-DXS67-DXS68-DXS28-AHC-GK-DMD-cen.