(MDR1 / ABCB1) this gene encodes the P-glycoprotein transporter that works in the intestines, biliary canalicular cells, renal tubular cells, and brain capillary endothelial cells. A deletion mutation in this gene results in dysfunction in the drug transporter which impacts the blood-brain barrier and leads to abnormal toxicity of certain drugs. The inheritance pattern is autosomal recessive.

(SCL7A9) in cats is an inherited metabolic disease that is relatively common in dogs, but rare in cats. The condition is characterized by defective amino acid reabsorption, leading to the formation of cystine stones in the kidney, ureter and the bladder (cystine urolithiasis). This can lead to urinary obstruction. Urethral obstruction is a serious medical emergency which requires immediate veterinary attention. This is because the obstruction of urethra can lead to renal failure and uremia. If left untreated, such conditions may lead to death in less than 72 hours.

(FXII) also known as Hageman deficiency, is the most common blood factor deficiency in cats. Factor XII deficiency does not present itself as a bleeding tendency but is considered to have an effect on blood clot stability and the maintenance of pregnancy. Affected queens can have significantly higher stillbirth rates of kittens than carriers or genetically normal cats. Factor XII deficiency has been reported in the Domestic Shorthair, Domestic Longhair, Himalayan, and Siamese. A causative mutation has been found for Domestic Shorthair cats. The inheritance pattern is autosomal recessive.

(HCM) is a type of heart disease that results in thickening or “hypertrophy” of the heart muscle. HCM is the most common type of heart disease in cats and can be inherited or result from other predisposing health disorders. Mutations that predispose to HCM are reported for Ragdolls and Maine Coon cats.

(MPS) is a group of lysosomal storage disorders in which a mutation causes the decreased function of a specific enzyme required to break down glycosaminoglycan’s (GAGs). The GAGs collect in cells, blood and connective tissues and cause abnormalities in appearance and function of body systems. Affected cats may have flat, broad faces, large heads, small ears, thick skin over the dorsal neck, wide cervical vertebrae and hip subluxation as well as other manifestations of the disease. Clinical signs of the disease are usually visible within the first few months of life.

(PKD) is an autosomal dominant inherited condition in cats is characterized by the development of fluid-filled sacs (cysts) in the kidneys. The cysts increase in number and size over time and overwhelm the ability of the kidneys to function properly resulting in renal failure. Cysts may be present at birth in affected cats, but disease may not be clinically evident until later, typically before 7 years of age.

(CEP290) this mutation can lead to “late onset” blindness. Cats homozygous for this mutation are born without evidence of clinical disease or detectable abnormalities in the eye during a clinical exam, the disease develops slowly over time. Lesions in the fundus can be observed by full-field flash electroretinography (ERG) as early as 8 months, and are visible via opthalmoscopic exam around 1.5-2 years. Loss of vision occurs slowly and typically the end stage of the disease is reached by 4-7 years of age. The (CRX) mutation causes an “early-onset” disease with clinical signs evident by 4-5 weeks of age. Visual impairment is usually evident within the first 4 months of life. Inheritance of this disorder is autosomal dominant and the breeding of two carriers is likely to result in non-viable offspring.

(PK deficiency) is a recessive inherited disease which was initially discovered in Abyssinian and Somali breeds, but can also affect random bred domestic shorthair cats. PK deficiency is caused by a mutation in the PKLR gene which encodes the pyruvate kinase enzyme. Without this enzyme, erythrocytes (red blood cells) break down easily in circulation resulting in an abnormally low level of these cells (hemolytic anemia). Clinical signs include severe lethargy, weight loss, jaundice, and abdominal enlargement.

(SMA) is a recessively inherited genetic disorder in Maine Coon cats caused by a mutation in the LIX1 gene. The disorder results in the loss of neurons (nerve cells) that affect muscles in the limbs. The result is weakness and instability in posture and gait. By about 5 months of age muscle atrophy, or shrinking of the muscles in the legs is evident. Although physically debilitated, cats can survive into adulthood.