X-Linked Severe Combined Immunodeficiency Disease (Basset Hound Type)
Affected Genes: IL2RG
Inheritance: X-Linked Recessive
Variant(canFam6):
chrX:46311728-46311731: 4 bp deletion GAGG
Breed: Basset Hound
General Information: X-linked Severe Combined Immunodeficiency (XSCID) in Basset Hounds manifests early in life, typically around 6 to 8 weeks of age, when affected puppies begin to exhibit a range of symptoms due to their severely compromised immune systems. These symptoms include failure to thrive, poor growth, significant weight loss, chronic diarrhea, vomiting, and profound lethargy. Affected puppies often suffer from recurrent or persistent infections, including respiratory, skin, eye, and ear infections, and they may lack palpable lymph nodes—a key component of the immune system. Due to the severity and recurrent nature of these infections, affected puppies rarely survive beyond 4 months of age without intervention.
How to Read Your Dog's Test Results for this Genetic Variant:
Two Variants Detected: Dog Likely Affected
One Variant Detected: Dog Unlikely Affected
No Variants Detected: No Effect
Gene / Testing Information: Genetic testing for X-linked Severe Combined Immunodeficiency (XSCID) in Basset Hounds focuses on mutations in the IL2RG gene, which is crucial for diagnosing this specific form of immunodeficiency. The disease follows an X-linked recessive inheritance pattern, meaning that it primarily affects males, who require only one copy of the mutated gene from their mothers to express the disease. Female carriers, who possess one copy of the mutated gene, typically do not show symptoms but have a 50% chance of passing the defective gene to their male offspring, who will be affected by the disease. Genetic testing is essential for identifying carriers and affected individuals to inform responsible breeding decisions. To prevent the propagation of this debilitating condition, it is advised not to breed carriers. Males born to carrier females should be tested early to confirm their status, allowing for better management of their health. Non-carrier Basset Hounds are not at risk of producing affected offspring, ensuring a healthier future generation.
References:
Henthorn PS, Somberg RL, Fimiani VM, Puck JM, Patterson DF, Felsburg PJ. IL-2R gamma gene microdeletion demonstrates that canine x-linked severe combined immunodeficiency is a homologue of the human disease. Genomics 1994 23(1):69-74.