Sabino is a general description for a group of similar white spotting patterns. The sabino pattern is described as irregular spotting usually on the legs, belly and face, often with roaning around the edges of the white markings. A mutation has been discovered that produces one type of sabino pattern, it has been named Sabino1 as it is not present in all sabino-patterned horses. More mutations will probably exist that account for other sabino patterns. The Coat Colour Sabino 1 test (P785) tests for the genetic status of the KIT gene. This gene has two variants (alleles). The allele SB1 is semi-dominant. One copy of the SB1 allele results in horses with broken Sabino markings and possibly only a small amount of white. Two copies of the SB1 allele result in at least 90% white, also referred to as Sabino-white. The allele N is recessive and does not have an effect on the basic colour.
The Coat Colour Sabino 1 test encloses the following results, in this scheme the results of the Coat Colour Sabino 1 test are shown in combination with the possible results for the tests that determine the basic Coat Colour (Coat Colour Chestnut and Coat Colour Agouti test):
|
Result Sabino 1 |
Result Chestnut + Agouti |
Coat Colour |
Description |
|---|---|---|---|
|
N/N |
e/e + A/A, A/a or a/a
|
Chestnut, Sorrel
|
Not Sabino 1. The basic colour chestnut/sorrel is not modified unless modified by other colour modifying genes. It can only pass on allele N to its offspring. |
|
N/N |
E/E or E/e + A/A or A/a |
Bay, Brown |
Not Sabino 1. The basic colour bay/brown is not modified unless modified by other colour modifying genes. It can only pass on allele N to its offspring. |
|
N/N |
E/E or E/e + a/a |
Black |
Not Sabino 1. The basic colour is not black modified unless modified by other colour modifying genes. It can only pass on allele N to its offspring. |
|
N/SB1 |
e/e + A/A, A/a or a/a
|
Chestnut/sorrel sabino |
Sabino 1 pattern. One copy of the SB1 allele. Horse typically may have 2 or more white legs, blaze, spots or roaning in the midsection and jagged margins around white areas unless modified by other colour modifying genes. It can pass on either allele N or SB1 to its offspring. |
|
N/SB1 |
E/E or E/e + A/A or A/a |
Brown/bay sabino |
Sabino 1 pattern. One copy of the SB1 allele. Horse typically may have 2 or more white legs, blaze, spots or roaning in the midsection and jagged margins around white areas unless modified by other colour modifying genes. It can pass on either allele N or SB1 to its offspring. |
|
N/SB1 |
E/E or E/e + a/a |
Black sabino |
Sabino 1 pattern. One copy of the SB1 allele. Horse typically may have 2 or more white legs, blaze, spots or roaning in the midsection and jagged margins around white areas unless modified by other colour modifying genes. It can pass on either allele N or SB1 to its offspring. |
|
SB1/SB1 |
e/e + A/A, A/a or a/a
|
Chestnut/sorrel sabino |
Sabino 1 pattern. Two copies of the SB1 allele. Horse is complete or nearly complete white unless modified by other colour modifying genes. It can only pass on allele SB1 to its offspring. |
|
SB1/SB1 |
E/E or E/e + A/A or A/a |
Brown/bay sabino |
Sabino 1 pattern. Two copies of the SB1 allele. Horse is complete or nearly complete white unless modified by other colour modifying genes. It can only pass on allele SB1 to its offspring. |
|
SB1/SB1 |
E/E or E/e + a/a |
Black sabino |
Sabino 1 pattern. Two copies of the SB1 allele. Horse is complete or nearly complete white unless modified by other colour modifying genes. It can only pass on allele SB1 to its offspring. |
