Five mutations in the androgen receptor gene, located on the X chromosome, are known to result in androgen insensitivity. Androgen insensitivity syndrome causes male horses to be sterile and appear phenotypically female.
Congenital stationary night blindness (CSNB) is an inherited condition in which affected individuals are unable to see in low light or dark conditions. This test detects a causal variant specific to Tennessee Walking Horses.
Distichiasis is a condition in which the eyelashes grow from an abnormal position on the edges of the eyelids. These misplaced lashes can contact the cornea (clear ‘window’ of the front of the eye), leading to irritation and corneal ulcers, which can impact vision.
Dominant white is a variable white spotting pattern caused by many different mutations in the KIT gene. The VGL tests for the four most common mutations known as W5, W10, W20, and W22. Homozygosity for W5, W10, or W22 is thought to be non-viable.
Dun is a coat color dilution characterized by lightening of the coat, with the head, lower legs, mane, and tail undiluted. Oftentimes, dun is also characterized by "primitive markings" such as a dark dorsal stripe, barring of the legs, shoulder stripes, and "cobwebbing" on the forehead.
Equine familial isolated hypoparathyroidism (EFIH), previously called idiopathic hypocalcemia, is an invariably fatal condition that causes involuntary contraction of muscles and seizures due to low blood calcium concentrations in Thoroughbred foals.
The gray gene causes progressive depigmentation of the hair, often resulting in a color that is almost completely white by 6-8 years of age. The individual gray test will determine the number of copies of the gray allele (zygosity). The coat color panel tests detect presence or absence of the gray allele.
Hereditary equine regional dermal asthenia (HERDA) is an inherited skin condition primarily found in Quarter Horses that is characterized by hyperextensible skin, scarring, and severe lesions along the back of affected horses.
Pre-implantation genetic diagnosis (PGD) is a procedure used to screen embryos recovered after uterine flush to determine sex and genetic traits through DNA testing prior to implantation in the uterus.
Junctional epidermolysis bullosa (JEB) is an inherited disease that causes moderate to severe blistering of the skin and mouth epithelia, sloughing of hooves in newborn foals, and skin lesions that develop as the foal ages. This test detects a causal variant specific to Belgians and related breeds.
Lavender foal syndrome (LFS) is an inherited lethal coat color dilution found primarily in Arabian horses that is characterized by a dilute lavender, pale pink, or silver coat accompanied by severe neurological abnormalities.
Leopard complex or appaloosa spotting is a white pattern in horses characterized by a variable amounts of white in the coat with or without pigmented leopard spots. Horses homozygous for this variant have an ocular condition known as congenital stationary night blindness.
Malignant hyperthermia (MH) is an inherited disease in which affected horses can be triggered by halogenated anesthetics, succinylcholine, stress, or excitement, which can induce a hyper-metabolic state characterized by symptoms including muscle contracture, elevated temperature, and an irregular heart rhythm.
Multiple congenital ocular anomalies (MCOA) is an inherited eye disorder that is associated with the silver dilution and is characterized by ocular cysts, enlargement of the cornea, abnormally formed iris/retina, and additional abnormalities.
Myosin-heavy chain myopathy (MYHM) is a muscle disease in Quarter Horses and related breeds that results in two distinct clinical disease presentations, immune-mediated myositis (IMM) and non-exertional rhabdomyolysis. Both presentations involve muscle loss or damage and are linked to the same genetic variant.
Naked foal syndrome (NFS) is an inherited disorder found in the Akhal-Teke breed and is characterized by hairlessness, abnormal teeth development, digestive disorders, persistent diarrhea, and laminitis-like problems.
Occipitoatlantoaxial malformation (OAAM), an inherited developmental condition primarily found in Arabian horses, causes abnormal development of the vertebrae and results in compression of the upper cervical cord with subsequent neurological damage.
Type 1 Polysaccharide Storage Myopathy is a glycogen storage disease that results in the accumulation of abnormal complex sugars in muscle cells, which can lead to muscle pain, weakness, and reluctance to move.
Severe combined immunodeficiency (SCID), an inherited condition primarily affecting Arabians, is characterized by an underdeveloped immune system that results in foals with elevated temperatures, respiratory stress, and diarrhea.
The silver dilution dilutes black/brown pigment to lighten the manes and tails of black and bay horses to a flaxen or silver gray. The silver dilution is also associated with an inherited ocular syndrome known as Multiple Congenital Ocular Anomalies (MCOA).
Skeletal atavism, an inherited bone development disorder found in Miniature Horses and Shetland Ponies, is characterized by severe angle anomalies and deformation of the front knee and hock. Affected horses typically display short legs, clubfootedness, and impaired movement.
Splashed white is a variable white spotting pattern characterized by a broad blaze, extended white markings on the legs, variable white spotting on the belly, and often blue eyes. Six mutations in two different genes have been shown to cause the splashed white pattern.
SynchroGait® is a diagnostic DNA test for a genetic variant (A) that has a major impact on the gait and coordination of horses. The discovery by researchers in Sweden showed that the mutation “facilitates lateral gaits, ambling and pace, and inhibits the transition from trot or pace to gallop”. The gait A variant has been identified as a major genetic factor for performance in trotting horses and ability to perform the additional “flying pace” in Icelandic horses.