Alpha-thalassemia-X-linked intellectual disability syndrome

The X-linked recessive syndrome is predominantly male in the form of an alpha-thalassemia associated with facial dysmorphism, genital abnormalities, and severe developmental delays. The linguistic abilities of the patients are severely impaired. Cases were described in which no alpha thalassemia was present.

Heterozygous women have neither physical nor mental disabilities. The cause is manifested in the mutation of the ATRX gene on the chromosome Xq21.1, which encodes the ATRX protein. Thus, in heterochromatic regions, there is a change in the methylation pattern of the DNA. However, it is not yet known how it comes to the clinical symptoms.