This information is provided by the National Institutes of Health (NIH) Genetic and Rare Diseases Information Center (GARD).
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 is caused by variants (mutations) in the AHDC1 gene. Inheritance is autosomal dominant but all reported cases to date have been due to new mutations (de novo), in individuals with no family history. Treatment and management is supportive, and ideally, should involve several specialists. This may include careful monitoring of the airways, continuous positive airway pressure at night, frequent growth assessments, physical therapy and early interventions to maximize developmental potential.
For more information, visit GARD.