Hyperlipoproteinemia

Hyperlipoproteinemia is a metabolic disorder resulting from insufficient lipoprotein lipase, a key enzyme in lipid metabolism. This imbalance leads to increased levels of triglycerides in the blood, as well as retarded growth and increased probability of stillbirths. The associated variant is located in the LPL gene, responsible for encoding lipoprotein lipase.

Symptoms

Significantly elevated triglyceride levels cause the presence of milky plasma, the appearance of fatty deposits under the skin (xanthomas) and visible fat in the blood vessels of the retina (lipemia retinalis). In addition, affected cats show growth problems and have an increased incidence of stillbirths.

Disease Management

Management of the disease focuses on dietary modification. It is essential to provide a low-fat diet to help control blood triglyceride levels, although this is not always sufficient to normalize levels. In addition, specific supplements and medications may be considered to help reduce plasma lipid concentration.

Genetic basis

This disease follows an autosomal recessive mode of inheritance. Autosomal recessive inheritance means that the cat, regardless of sex, must receive two copies of the mutation or pathogenic variant to be at risk of developing the disease. Both parents of an affected cat must carry at least one copy of the mutation. Animals with only one copy of the mutation are not at increased risk of developing the disease, but may pass the mutation on to future generations. Breeding between cats carrying genetic variants that may cause disease, even if they do not show symptoms, is not recommended.

Technical report

Hyperlipoproteinemia, also called hypertriglyceridemia, lipoprotein lipase deficiency or chylomicronemia in cats, is a genetic disease that results in an excess of triglycerides in the blood due to a deficiency of the enzyme lipoprotein lipase. This enzyme is essential in lipid metabolism, as it is responsible for hydrolyzing triglycerides present in lipoproteins such as chylomicrons and very low density lipoproteins (VLDL), converting them into free fatty acids that can be absorbed by tissues, especially adipose and muscle tissue, where they are used as a source of energy. The gene encoding lipoprotein lipase is LPL, and a point mutation (c.1315G>A) at the carboxyl end of this gene has been linked to hyperlipoproteinemia. This variant affects a highly conserved amino acid residue in multiple species, involved in lipid binding and interaction with the LDL-related receptor. In addition to sharing a clinical phenotype similar to humans with LPL deficiency, these cats show a high incidence of stillbirths, which is thought to be related to the inability of the mothers to mobilize essential fatty acids during gestation.

Most affected breeds

Not specified

Bibliography

Ginzinger DG, Lewis ME, Ma Y, et al. A mutation in the lipoprotein lipase gene is the molecular basis of chylomicronemia in a colony of domestic cats. J Clin Invest. 1996 Mar 1