Gangliosidosis GM1 in Korat and Siamese cats

Gangliosidosis GM1 is a sporadic lysosomal disease in which GM1 gangliosides accumulate in various tissues due to a deficiency of the enzyme ß-galactosidase. The disease is characterized by progressive neuromuscular dysfunction and impaired growth from an early age.

This disease is caused by the mutation c.1448G>C in the GLB1 gene. GLB1 encodes the enzyme ß-galactosidase, whose task is to break down the GM1 ganglioside into its
constituents.

GM1 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.

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References:

Martin, DR., Rigat, BA., Foureman, P., Varadarajan, GS., Hwang, M., Krum, BK., Smith, BF., Callahan, JW., Mahuran, DJ., Baker, HJ. : Molecular consequences of the pathogenic mutation in feline GM1 gangliosidosis. Mol Genet Metab 94:212-21, 2008. Pubmed reference: 18353697