Burmese Head Defect
A recessive mutation that causes a congenital craniofacial defect in Burmese cats has been discovered by the Lyons Feline Genetics Research Laboratory at UC Davis.The mutation affects function of a gene significant for facial development.A scientific manuscript for the publication of the work is in preparation.
The Burmese Head Defect mutation is common in the Contemporary lines of Burmese in the United States. One copy of the mutation does not cause the craniofacial defect but may produce a shortened facial structure (brachycephaly). Studies are underway to determine if cats that have one copy or no copies of the mutation can be identified just by facial type. Cats with two copies of the mutation have the severe craniofacial defect that is incompatible with life.
The VGL offers the DNA test for Burmese Head Defect to assist owners and breeders in identifying affected and carrier cats. The tests are done with DNA collected from buccal swabs thus avoiding invasive blood collection. Breeders can use these tests as a tool to avoid breeding carriers together which would produce 25% affected offspring.
Results reported as:
|Test Result||Burmese Head Defect|
|N/N||Normal, cat does not have Burmese Head Defect mutation|
Carrier, cat has one copy of Burmese Head Defect mutation. Breedings between carriers are expected to produce 25% affected kittens.
Burmese Head Defect is not related to Midline Defect, a genetic disease which can present head malformation among other abnormalities. Midline Defect appears more common in European lines of Burmese cats and is currently under investigation. No genetic test is available at this time for Midline Defect.
Burmese Hypokalemia, also known as Familial Episodic Hypokalaemic Polymyopathy, is a recessive genetic defect characterized by episodes of low serum potassium levels and high CPK (creatine phosphate kinase, an enzyme that indicates muscle damage). Clinical signs include episodes of skeletal muscle weakness which can affect the whole animal or may be restricted to certain muscles. This is most obvious in the neck muscles, but sometimes occurs in just the limbs. As a result affected cats may show problems with walking and holding their head correctly. The disease is not typically fatal and affected cats usually can be managed by adding potassium supplements to their diet. For specifics on management of this condition, owners are urged to consult with their veterinarian.
Breeds that are at risk for this disease include: Burmese and outcrosses such as Burmilla, Bombay, Cornish Rex, Devon Rex, Singapura, Sphynx, Australian Mist, Tiffanie, and Tonkinese.
The genetic mutation responsible for this disease has been identified by a team of researchers from the University of Bristol (England), the Lyons Feline Genetics Research Laboratory at UC Davis, University of Sydney, Massey University and Justus Liebig University. This discovery has allowed development of a genetic test that allows identification of carrier and affected cats.
The VGL offers the DNA test for Burmese Hypokalemia to assist owners and breeders in identifying affected and carrier cats. The tests are done with DNA collected from buccal swabs thus avoiding invasive blood collection. Breeders can use these tests as a tool to avoid breeding carriers together which would produce 25% affected offspring.
Results reported as:
|Test Result||Burmese Hypokalemia|
|N/N||Normal, cat does not have Burmese Hypokalemia mutation|
Carrier, cat has one copy of Burmese Hypokalemia mutation. Breedings between carriers are expected to produce 25% affected kittens.
GM2 gangliosidosis is a degenerative, fatal neurological disease characterized by severe muscle tremors and loss of motor control. In Burmese cats, the disease is caused by a mutation in the feline hexoaminadase β-subunit (HEXB) gene which leads to abnormal swollen neurons and brain lesions. The inherited condition in affected kittens is first observed at 6-8 weeks of age beginning with mild tremors and leading to difficulty eating and lack of coordination. The condition is inherited as a recessive, autosomal disorder.
Results reported as:
|Test Result||GM2 Gangliosidosis Status|
|N/N||Normal, cat does not have GM2 Burmese mutation*|
|N/GM2||Carrier, cat has one copy of GM2 Burmese mutation. Breedings between carriers will be expected to produce 25% affected kittens.|
* This test is specific for the 15 base pair deletion of HEXB found in Burmese cats and will not detect other HEXB mutations known to exist in other breeds of cats.
Bradbury A.M., N.E Morrison, M. Hwang, N.R. Cox, H.J. Baker, D.R. Martin. Neurodegenerative lysosomal storage disease in European Burmese cats with hexosaminadase β-subunit deficiency. Molecular Genetics and Metabolism (2009), doi:10.1016/j.ymgme.2009.01.003