Leopard Complex Spotting (LP) and Congenital Stationary Night Blindness (CSNB1)
Code: P311
Short description
Leopard Complex Spotting (LP), also known as Coat Colour Appaloosa pattern or Appaloosa spotting, refers to the leopard-like coat pattern distinctive to the Appaloosa breed, characterized by a white coat flecked with small, dark spots.
General information
Leopard Complex Spotting (LP), also known as Coat Colour Appaloosa pattern or Appaloosa spotting, refers to the leopard-like coat pattern distinctive to the Appaloosa breed, characterized by a white coat flecked with small, dark spots. This trait is caused by an autosomal incompletely dominant mutation in the Transient Receptor Potential Cation Channel, Subfamily M, Member 1 (TRPM1) gene. The resulting phenotype varies depending on whether the horse is homozygous or heterozygous. Horses that are homozygous have typically little to no leopard spots, while heterozygous horses display pigmented spots within the white-patterned areas of their coat. The extent of white in leopard complex-patterned horses is influenced by other genes, including PATN1, for which testing is also available. Breeds most commonly associated with this gene include the American Miniature Horse, Appaloosa, Australian Spotted Pony, British Spotted Pony, Knabstrupper, Miniature Horse, Noriker, Pony of the Americas, Falabella and Thoroughbred.
Horses homozygous for the mutation are also affected by Congenital Stationary Night Blindness 1 (CSNB1), a condition that causes an inability to see in low-light conditions.
Specifications
| Breeds | American Miniature Horse, Appaloosa, Australian Spotted Pony, British Spotted Pony, Falabella, Knabstrupper, Miniature Horse, Noriker, Pony of the Americas, Thoroughbred |
|---|---|
| Gene | TRPM1 |
| Chromosome | 1 |
| Organ | Sensory organs |
| Specimen | Hair, Blood EDTA, Blood Heparin, Semen, Tissue |
| Mode of Inheritance | Autosomal Incomplete Dominant |
| Also known as | LP; CSNB |
Clinical features
LP spotting tends to be symmetrical, with the greatest concentration of spots centred on the hips. It also can include white sclera, striped hooves and mottled pink skin around the eyes, muzzle, anus and genitalia. Horses homozygous for the mutation and affected by CSNB are born unable to see in low-light conditions, which can lead to nervousness, confusion, and difficulties during training. Affected horses may also exhibit strabismus (crossed or misaligned eyes) and nystagmus (abnormal or involuntary eye movements). While CSNB is present from birth and does not progress over time, recent research indicates that horses homozygous for the mutation have an increased risk of developing Equine Recurrent Uveitis (ERU). ERU, also known as moon blindness, is a progressive condition and the leading cause of blindness in horses.
References
Pubmed ID: 24167615
Year published: 2013
Omia ID: 1341
Omia variant ID:
Turnaround information
- 20 working days