De novo truncating mutations in the AHDC1 gene encoding the AT-hook DNA-binding motif-containing protein 1 are associated with intellectual disability and developmental delay

Original research report by H. Yang et al. (2015).

Read the report here.

Researchers tested 2,157 people using whole-exome sequencing to identify 7 people with changes in the AHDC1 gene. The changes were “de novo,” meaning they were not found in either parent. Changes in the AHDC1 gene are believed to disrupt brain development and to be associated with intellectual disability. The people the researchers identified ranged in age from 2 to 16 years. All of them had significant intellectual disability or developmental delay and limited or no verbal skills, among other clinical features. These features are summarized below.

Clinical Features in Individuals with an AHDC1 gene change Number of Individuals with Feature
Developmental delay/Intellectual disability 7/7
Limited or no verbal skills 7/7
Hypotonia (Low muscle tone) 6/7
Differences in facial features 6/7
Current growth problems with or without a history of growth problems 5/7
Behavioral issues 5/7
Structural abnormalities of the eye(s) 5/7
Abnormal brain imaging 5/7
Sleeping issues (i.e. sleep apnea, restlessness, trouble falling and/or staying asleep, etc.) 4/7
Autism Spectrum Disorder (ASD) Diagnosis 2/7
Seizures/Epileptic activity 2/7