Testing of cats: SMA
Related tests
- Combination Maine Coons HCM + Factor XI deficiency + Factor XII deficiency + PK deficiency + SMA + Cystinuria, type B + Blood Group DNA test
Spinal muscular atrophy (SMA) in Maine Coon cats
For SMA testing we prefer a blood sample as the microflora of the oral cavity can interfere with the test results. We can also accept buccal swabs – however, if the test cannot be finished when a buccal swab is used, the customer will also pay the total cost of repeated analysis. Thank you for your understanding.
The Spinal Muscular Atrophy (SMA) is a disease caused by degeneration of spinal cord neurons that are responsible for conscious muscle movement. The SMA abbreviation includes genetically heterogeneous group of disorders that vary in clinical severity, from lethal in infancy to onset of mild weakness in adulthood.
The progressive loss of the neuron function in the first few months of life leads to muscle weakness that first becomes apparent at 3-4 months of age. Affected kittens develop an odd gait with a sway of the hindquarters and sometimes connected with the transfer of the weight of the body to the toes. By 5-6 months of age they are too weak in the hindquarters to readily jump on furniture and are clumsy when jumping down. Affected kittens are not in pain; they eat normally and play avidly. The most affected cats live very comfortable and the length of the life depends on the severity of the affection.
SMA in Maine Coon cats is caused by 140-kb deletion in LIX1-gene on chromosome A1q. Although the LIX1-function has not been fully clarified yet, the predicted secondary structure is compatible with a role in RNA-metabolism. The LIX1 expression is largely restricted to the central nervous system, primarily in spinal motor neurons, thus offering explanation of the restriction of their function in case of feline SMA.
SMA is an autosomal recessive disorder. The disease affects cats with P/P (positive / positive) genotype only. Cats with P/N (positive /negative) genotype are clinically without any symptoms. They are genetically considered carriers of the disease (heterozygotes). In offspring of two heterozygous animals following genotype distribution can be expected: 25 % N/N (healthy non-carriers), 25 % P/P (affected), and 50 % N/P (healthy carriers). Because of high risk of producing affected offspring, mating of two N/P animals (carriers) can not be recommended.
Citation:
John C. Fyfe et al.: An ~140-kb deletion associated with feline spinal muscular atrophy
implies an essential LIX1 function for motor neuron survival , Genome Res. 2006 16: 1084-1090