PIDDGEN
Welcome to Stellenbosch University

Division of Molecular Biology and Human Genetics

Primary Immunodeficiency Disease and Tuberculosis Susceptibility,
Genetic Research Group

PID ​Diagnostic Tests and Genetic Counselling

 

The definitive diagnosis of PIDs depends on both clinical and immunological evaluation as well as genetic testing, since the physical signs may be nonspecific, subtle, or even absent in early diagnosis. Therefore, to confirm a clinically suspected diagnosis of genetic immunodeficiency, the evaluation of an immunological disorder in any patient should lead to an investigation of the potential underlying genetic cause. PIDDGEN is in the process of developing several genetic tests aimed at detecting mutations in individuals affected with immunodeficiencies. These methods are based on PCR amplification and Sanger sequencing of target DNA segments from affected individuals or at-risk relatives.

 

 
List of currently vailable Diagnostic Genetic Tests:

XLA        Gene BTK:           Test available for Exon 3

The BTK gene comprises 19 exons

CGD       Gene CYBB:        Test available for Exon 10

Gene CYBB:        Primers also available for exons 3, 4, 5, 7, 8.

Almost 2/3 of CGD cases are caused by mutations in the CYBB gene This gene comprises 13 exons

XLP         Gene SH2D1A: Test available for Exons 1-4

Whole coding sequence is covered

NOD2    Gene NOD2: Test available for Exons 1-12

Whole coding sequence is covered

Testing for other genes can be arranged, or referred elsewhere to local and international laboratories if specialised or complex testing is required.

Genetic Counselling

Genetic counselling is aimed at helping individuals understand the genetic and medical implications of a condition, which includes discussion of the relevant recurrence risks of a specific condition and diagnostic tests available. For a genetic research study, genetic counselling is relevant both pre-test (explaining the aims, procedures, risks and benefits of the research study and obtaining consent), and post-test (feeding back potentially complex genetic results).

More information about genetic counselling and the genetic services offered at Tygerberg Hospital is available here.