The Disease
Severe Combined Immunodeficiency of Arabian foals is a fatal disease caused by the lack of B- and T-lymphocytes. It is estimated that 2-3% of Arabian foals have SCID. This would suggest that 25% of Arabian horses carry the defect gene. 

The Trait of Inheritance
Severe Combined Immunodeficiency is an inherited autosomal recessive trait. This means that a horse can be genetically clear (homozygous normal), affected, or a carrier (heterozygous). The carriers can spread the diseased gene in the population. Therefore, reliable information on non-affected horses is the key to controlling this disease.

The mutation-based gene test and its advantages
The genetic defect leading to the disease has been identified. By DNA testing the responsible mutation can be shown directly. This method provides a very high accuracy test and can be done at any age. It offers the possibility to distinguish not only between affected and clear horses, but also to identify clinically healthy carriers. This is an essential information for controlling the disease in the breed as carriers are able to spread the disease in the population, but can not be identified by means of common laboratory diagnostic.

Requirements
The test is performed out of  EDTA whole blood (1 ml). The results are out about one week after arrival of the sample in our laboratory.