[MIM 615 829]

(Intellectual deficiency - obstructive sleep apnea - mild dysmorphism linked to AHDC1, syndrome, XGS syndrome)

Prevalence: < 1.106. Autosomal dominant transmission of a mutation in the AHDC1 gene (1p36.1 - p35.3), but reported cases are usually sporadic mutations.

Association of mental retardation (difficulties in speech development) and:

-        laryngotracheomalacia

-        facial dysmorphism: micrognathia, hypertelorism, broad forehead, flattened nose root, large and low set ears, slanting up or down palpebral  fissures, convergent strabismus

-        hypotonia, ataxia, sometimes autistic traits or convulsions

-        scoliosis

-        cerebral anomalies abnormalities at MRI: hypoplasia of the corpus callosum, myelination delay, cyst of the posterior cranial fossa

Anesthetic implications:

obstructive sleep apnea, risk of difficult intubation, mental deficiency

References : 

-        Jiang Y, Wangler MF, McGuire AL, Lupski JR et al.
The phenotypic spectrum of Xia-Gibbs syndrome.
Am J Med Genet 2018 ; 176A : 1315-26.

Updated: December 2018