Prevalence
So far, only seven patients with homozygous mutation in DEAF1 (belonging to four apparently unrelated families) have been reported in the medical literature. Nevertheless, more individuals will likely be found as genetic testing is more commonly used for undiagnosed intellectual disability.
Main clinical features
Homozygous pathogenic variants in the DEAF1 gene cause dyskinesia, seizures, and intellectual developmental disorder (DYSEIDD). Patients may also have hypotonia, severe behavioral problems and brain structural abnormalities.
Diagnosis
DEAF1 variants can be identified using molecular genetic testing, either by:
- sequencing of the DEAF1 gene;
- exome/genome sequencing.
Inheritance
DYSEIDD is inherited in an autosomal recessive manner.
To date, all patients inherited the pathogenic DEAF1 variants from their (consanguineous) parents.
Thus, the recurrence risk for future pregnancies is 25%.
No individual with homozygous DEAF1 variants has been known to reproduce.