Xp21 deletion in female patients with intellectual disability: Two new cases and a review of the literature

Xp21 continuous gene deletion syndrome is characterized by complex glycerol kinase deficiency (GK), adrenal hypoplasia congenital (NROB1), intellectual disability and/or Duchenne muscular dystrophy (DMD). The clinical features depend on the size of the deletion, as well as on the number and the nature of the encompassed genes. More than 100 male patients have been reported so far, while only a few cases of symptomatic female carriers have been described. We report here detailed clinical features and X chromosome inactivation analysis in two unrelated female patients with overlapping Xp21 deletions presenting with intellectual disability and inconstant muscular symptoms.