In order to detect adenine de aminase (ADA) deficiency, the following tests may be performed:
1. Total lymphocyte count
2. Genetic testing.
Lymphocytes help the body to fight diseases. The first test would help to detect total lymphocyte count in the person. Lymphocyte count in a person diagnosed with ADA is greatly reduced. When lymphocyte count drops, the body's ability to fight diseases decreases and hence the person gets prone to different diseases.
The second test needs some molecular understanding. ADA is caused by mutations in a gene present in chromosome number 20. Mutation means a change in the nucleotide sequence. So, if we analyse the gene sequence of the suspect and find deviation from the normal gene, we can predict that the person is suffering from ADA. This is what genetic testing is all about.
The affected ovum will deviate from the normal one in the above aspects.