XIGIS, AHDC1-related intellectual disability-obstructive sleep apnea-mild dysmorphism syndrome, Autosomal dominant intellectual disability 25
Type of disease: Rare Condition or Disease
Xia-Gibbs syndrome is a rare disorder of intellectual disability. People with this syndrome usually present with developmental delay (especially delays in speech), low muscule tone (hypotonia), failure to thrive, mildly unusual facial features (broad forehead, widely-spaced eyes (hypertelorism), big and low-set ears, flat nasal bridge, and thin upper lip), and breathing difficulties when sleeping (sleep apnea). The sleep apnea may be due to a collapse of the airway when breathing (tracheomalacia). Other signs and symptoms may include autistic features, seizures, lack of coordination (ataxia), behavioral problems, crossed-eyes (strabismus), and an abnormal lateral curvature of the spine (scoliosis). Males usually have more severe symptoms than females. Brain MRI may show several structural brain defects, such as thinning of the corpus callosum and posterior fossa cysts.
Xia-Gibbs syndrome (XIGIS) is caused by heterozygous mutation in the AHDC1 gene (615790) on chromosome 1p36.
Xia-Gibbs syndrome (XIGIS) is characterized by impaired intellectual development with absent or poor expressive language, obstructive sleep apnea, mild dysmorphic features, and brain abnormalities. Patients with XIGIS can have a broad clinical spectrum with multisystemic involvement in addition to neurologic manifestation.