Burmese Head Defect causes severe facial defects when two copies of the variant are present, and affected cats require humane euthanasia shortly after birth.

Acute Intermittent Porphyria (AIP) is caused by faulty enzyme activity and results in brownish discoloration of the teeth and urine in affected cats.

Acute Intermittent Porphyria (AIP) is caused by faulty enzyme activity and results in brownish discoloration of the teeth and urine in affected cats.

Acute Intermittent Porphyria (AIP) is caused by faulty enzyme activity and results in brownish discoloration of the teeth and urine in affected cats.

Acute Intermittent Porphyria (AIP) is caused by faulty enzyme activity and results in brownish discoloration of the teeth and urine in affected cats.

Acute Intermittent Porphyria (AIP) is caused by faulty enzyme activity and results in brownish discoloration of the teeth and urine in affected cats.

Autoimmune Lymphoproliferative Syndrome is a disease of the immune system which can cause the lymph nodes to become severely enlarged.

Chediak-Higashi Syndrome (CHS) is a metabolic disorder that causes partial albinism, prolonged bleeding, sensitivity to light and cataracts to develop at a young age.

Congenital Adrenal Hyperplasia is an endocrine disorder which leads to aggression, abnormalities of the genitalia, and excessive drinking and urination.

Congenital Erythropoietic Porphyria (CEP) is caused by faulty enzyme activity and results in brownish discoloration of the teeth and urine in affected cats.

Congenital Myasthenic Syndrome (CMS) is a condition that causes muscle weakness and fatigue.

Cystinuria is a condition that predisposes cats to form cystine crystals and stones within the urinary tract, which can then cause irritation and blockage.

Cystinuria is a condition that predisposes cats to form cystine crystals and stones within the urinary tract, which can then cause irritation and blockage.

Cystinuria is a condition that predisposes cats to form cystine crystals and stones within the urinary tract, which can then cause irritation and blockage.

Cystinuria is a condition that predisposes cats to form cystine crystals and stones within the urinary tract, which can then cause irritation and blockage.

Dihydropyrimidinase Deficiency is a condition that causes tiredness, weakness, vomiting, and high levels of ammonia in the blood.

The Earfold and Osteochondrodysplasia variant results in the breed defining folded ears of Scottish Fold cats and is associated with skeletal malformations and arthritis.

Factor XII Deficiency, also known as Hageman trait, is an asymptomatic blood factor deficiency. While it does not cause an abnormal tendency to bleed, it can be observed as prolonged blood clotting times during certain laboratory screening tests.

Factor XII Deficiency, also known as Hageman trait, is an asymptomatic blood factor deficiency. While it does not cause an abnormal tendency to bleed, it can be observed as prolonged blood clotting times during certain laboratory screening tests.

Familial Episodic Hypokalemic Polymyopathy causes episodes of muscle weakness and pain.

Glutaric Aciduria Type II causes loss of appetite, vomiting and seizures in young cats.

Glycogen Storage Disease results in low blood sugar levels leaving kittens and young cats weak. The condition leads to muscle wasting, seizures and cardiac failure.

GM1 Gangliosidosis causes muscle tremors, uncoordinated movements, and blindness.

GM2 Gangliosidosis causes muscle tremors, uncoordinated movements, difficulty eating, and blindness.

GM2 Gangliosidosis Type II causes muscle tremors, uncoordinated movements, difficulty eating, and blindness.

GM2 Gangliosidosis Type II causes muscle tremors, uncoordinated movements, difficulty eating, and blindness.

GM2 Gangliosidosis Type II causes muscle tremors, uncoordinated movements, difficulty eating, and blindness.

Hemophilia B, or Factor IX Deficiency, is a blood clotting disorder that can result in tiredness, decreased appetite, fever, lameness, and prolonged bleeding times after injury, trauma or surgery.

Hemophilia B, or Factor IX Deficiency, is a blood clotting disorder that can result in tiredness, decreased appetite, fever, lameness, and prolonged bleeding times after injury, trauma or surgery.

Hyperoxaluria Type II is a kidney disorder leading to severe weakness and kidney failure in young cats.

Hypertrophic Cardiomyopathy (Discovered in the Maine Coon) is a disorder in which the heart muscle wall increases in thickness, eventually leading to heart failure.

Hypertrophic Cardiomyopathy (Discovered in the Ragdoll) is a disorder where the heart muscle wall increases in thickness, eventually leading to heart failure.

Hypotrichosis is a disorder of the immune system causing kittens to be born hairless and to develop serious infections.

Lipoprotein Lipase Deficiency is a metabolic disorder that causes decreased body mass and reduced growth rates in affected kittens and can cause stillbirths in affected queens.

MDR1 Medication Sensitivity is a disorder caused by a defect to a drug pumping protein that plays an important role in limiting drug absorption and distribution (particularly to the brain). Cats with the MDR1 variant may have severe adverse reactions to some commonly used medications.

Mucopolysaccharidosis Type I is a disorder causing failure to thrive, facial and other skeletal abnormalities, tremors, and clouding of the eyes.

Mucopolysaccharidosis Type VI is a rare disorder causing dwarfism, degenerative joint disease, and clouding of the eyes.

Mucopolysaccharidosis Type VII is a disorder causing weakness, growth retardation, facial and other skeletal abnormalities, and clouding of the eyes.

Mucopolysaccharidosis Type VII is a disorder causing weakness, growth retardation, facial and other skeletal abnormalities, and clouding of the eyes.

Mucopolysaccharidosis Type VI Modifier causes a mild degenerative joint disease, but only if one copy of Mucopolysaccharidosis Type VI is also present.

Myotonia Congenita is a condition that results in stiff movement and delayed relaxation of muscles after exercise.

Polycystic Kidney Disease (PKD) is the most common inherited disease in cats. The disease causes the formation of fluid-filled cysts in the kidneys that can lead to kidney failure.

Progressive Retinal Atrophy (Discovered in the Abyssinian) is a disorder that causes degeneration of the light sensing retina at the back of the eye, resulting in vision loss.

Progressive Retinal Atrophy (Discovered in the Bengal) is a disorder that causes degeneration of the light sensing retina at the back of the eye, resulting in vision loss.

Progressive Retinal Atrophy (Discovered in the Persian) is a disorder that causes degeneration of the light sensing retina at the back of the eye, resulting in vision loss.

Pyruvate Kinase (PK) Deficiency is a disorder that causes anemia due to the breakdown of red blood cells.

Sphingomyelinosis causes progressive incoordination and tremors, enlargement of the spleen and liver, and changes in the lungs.

Sphingomyelinosis causes progressive incoordination and tremors, enlargement of the spleen and liver, and changes in the lungs.

Vitamin D-Dependent Rickets results in skeletal abnormalities caused by low blood calcium levels.

Amber (Discovered in the Norwegian Forest Cat)

The Amber variant results in a rare golden coat color called amber which was first discovered in Norwegian Forest Cats.

Dilution

The Dilution variant causes a lightening of coat color pigments. Black pigment is diluted to blue, chocolate to lilac, cinnamon to fawn and red to cream.

Polydactyly (Variant 2)

Polydactyly (Variant 2) may result in extra toes on all four feet.

Albinism (Discovered in Oriental breeds)

The Albino (Discovered in Oriental breeds) variant results in white fur, a pink nose, and pale blue eyes.

Charcoal (Discovered in the Bengal)

The Charcoal pattern presents as a dark face mask with a darkly shaded stripe on the back known as a dorsal stripe or "cape."

Chocolate

The Chocolate variant results in medium to dark brown or chocolate colored hair instead of black hair.

Cinnamon

The Cinnamon variant results in light brown or cinnamon colored hair instead of black or brown hair.

Colorpoint (Discovered in the Burmese)

The Colorpoint (Discovered in the Burmese) variant causes temperature-sensitive pigment production at the extremities or "points" (face, ears, feet and tail).

Colorpoint (Discovered in the Siamese)

The Colorpoint (Discovered in the Siamese) variant causes temperature-sensitive pigment production at the extremities or "points" (face, ears, feet and tail).

Glitter

The Glitter variant results in a softened hair texture and gives an iridescent sheen to the coat.

Hairlessness (Discovered in the Sphynx)

The Hairlessness (Discovered in the Sphynx) variant causes a cat to have little or no hair.

Long Hair (Discovered in many breeds)

The Long Hair (Discovered in many breeds) variant is one of four variants known to cause long hair in cats.

Long Hair (Discovered in the Norwegian Forest Cat)

The Long Hair (Discovered in the Norwegian Forest Cat) variant is one of four variants known to cause long hair in cats.

Long Hair (Discovered in the Ragdoll)

The Long Hair (Discovered in the Ragdoll) variant is one of four variants known to cause long hair in cats.

Long Hair (Discovered in the Ragdoll and Maine Coon)

The Long Hair (Discovered in the Ragdoll and Maine Coon) variant is one of four variants known to cause long hair in cats.

Lykoi Coat (Variant 1)

Lykoi Coat (Variant 1) is one of the variants known to result in the sparse coat of the Lykoi cat.

Lykoi Coat (Variant 2)

Lykoi Coat (Variant 2) is one of the variants known to result in the sparse coat of the Lykoi cat.

Mocha (Discovered in the Burmese)

The Mocha variant reduces dark pigment levels resulting in a lighter colored coat, aqua eyes, and a pink nose and paw pads.

Partial and Full White

The Partial and Full White variants can result in a partial white (bicolor) or full white appearance, depending on the length of variant inherited.

Polydactyly (Variant 1)

Polydactyly (Variant 1) may result in extra toes on either the front or all four feet.

Polydactyly (Variant 3)

Polydactyly (Variant 3) may result in extra toes on all four feet.

Rexing (Discovered in the Cornish Rex and German Rex)

The Rexing (Discovered in the Cornish Rex and German Rex) variant is one of the variants that results in a curly coat in cats.

Rexing (Discovered in the Devon Rex)

The Rexing (Discovered in the Devon Rex) variant is one of the variants that results in a curly coat in cats.

Russet (Discovered in the Burmese)

The Russet variant results in a gradual color change from brown tabby to red as the cat ages.

Short Tail (Variant 1)

Short Tail (Variant 1) is associated with a naturally short "bobbed" tail and was first discovered in Manx cats.

Short Tail (Variant 2)

Short Tail (Variant 2) is associated with a naturally short "bobbed" tail and was first discovered in Manx cats.

Short Tail (Variant 3)

Short Tail (Variant 3) results in a shortened tail with kinks or angles and was first discovered in Japanese Bobtail cats.

Solid Color

The Solid Color variant results in solid coloring of the hair shaft and is also known as Non-agouti.