What causes intellectual disability syndromes related to the DEAF1 gene?
DEAF1 is a gene, i.e. a DNA template for building a protein, that regulates the activity of other genes. The DEAF1 protein is present mostly in the brain, in particular before birth, during the early development of a baby. Changes in the DEAF1 gene cause intellectual disability and behavioural problems, most likely due to an abnormal interaction of the DEAF1 protein with other genes and proteins.
What is needed to confirm the diagnosis of intellectual disability syndromes related to the DEAF1 gene?
This diagnosis is confirmed by performing genetic testing in an affected individual, which enables the detection of a disease-causing change in the DEAF1 gene.
There are two possible ways to identify a DEAF1 change:
- Since the syndrome is not highly recognizable, most genetic changes in DEAF1 will be found by whole exome sequencing.
- If the individual’s characteristics raise the suspicion of an intellectual disability syndrome related to the DEAF1 gene, direct sequencing of the DEAF1 gene by Sanger sequencing can be performed.
The genetic testing can be arranged by a clinical geneticist and involves the collection of a sample of blood or saliva from the affected individual (and eventually the parents). Analysing the DNA of the patient and comparing it with the parents’ DNA may facilitate the detection of a DEAF1 disease-causing change that is present in the child, but that is not present in the healthy parents (i.e. a “de novo” change).