| Familial and de novo recurrent Xp11.22-p11.23 microduplication has been recently identified in males and females. To date, twelve patients have been described. All patients show moderate to severe intellectual deficit and speech delay. Seizures, early puberty and lower-extremity anomalies, including pes planus or cavus, fifth toe hypoplasia, and syndactyly, are common. Most affected females show preferential activation of the duplicated X chromosome. Duplications are mediated by nonallelic homologous recombination or Alu-mediated recombination. |