Test Detail

Test for the brindle pattern of the horse, characterized by irregular vertical stripes of darker hair and altered texture on the neck, back and croup. It detects the intronic variant in MBTPS2 associated with the trait. Complementary to, not a substitute for, clinical examination.

Applicable breed: Quarter Horse and Warmblood. Frequencies: limited data; few families have been described.

• Irregular vertical stripes of dark hair over the body, more visible on the neck, back and croup.
• Subtle change in hair texture and morphology.
• Phenotype of variable intensity, sometimes more evident in females.

The brindle pattern (BR1) was described in 2016 in a Quarter Horse family; Murgiano and colleagues mapped the locus to the X chromosome and identified an intronic variant in MBTPS2 with an effect on splicing.

• Given the X-linkage, advice differs between carrier males and females.
• Do not select exclusively for the pattern, which has variable expression.
• An affected male transmits the allele to all his daughters.
• Confirm the pattern with the phenotype, since penetrance is incomplete.

Differential diagnosis with roan, chimerism-related spotting and seasonal hair patterns. The variant affects splicing; no clinical consequences beyond hair color and texture have been described.

1. Murgiano 2016, An intronic MBTPS2 variant results in a splicing defect in horses with brindle coat texture (PMID 27449517); OMIA:002021-9796.