| Contents |
|---|
| Incontinentia Pigmenti |
| Summary |
| Understanding the Results |
| Disease Name and Genes |
| Inheritance |
Incontinentia Pigmenti
Summary
Incontinentia pigmenti (IP) is an inherited skin disorder that causes skin lesions soon after birth that develop into warty areas with hair loss. Wooley hair may grow back in these areas. Affected horses have streaks of light and dark coat color from birth. In addition, there are abnormalities of tooth, hoof, and eye development. Only affected mares have been observed; affected males die before birth.
The condition resembles Ectodermal Dysplasia (ED) in humans. Ectodermal Dysplasia is a collective term for a genetically distinct group of inherited disorders affecting ectodermal structures (skin, nails, and teeth).
Date of Last Update: 08/02/2016
Results
Understanding the Results
Results of the genetic test for Incontinentia Pigmenti (IP) are presented as shown below.
| Incontinentia Pigmenti (IP) | ||
|---|---|---|
| n/n | Clear | This mare tested negative for IP. |
| n/IP | Affected | Both the normal and mutant alleles are present. This mare is positive for the IP mutation and will show symptoms. |
Disease Name and Genes
Incontinentia Pigmenti (IP) is caused by a C to T substitution in the X-chromosomal IKBKG gene that changes an Arginine (R) codon in position 62 to a termination codon (IKBKG-R62X).
Inheritance
Incontinentia Pigmenti (IP) is caused by a dominant variant of the X-chromosomal IKBKG gene (GBE1-T34X). The recessive wild-type allele is abbreviated as n, with the dominant variant abbreviated as IP. Males inheriting the variant (IP/Y) die as embryos.
If a mare with the disorder (n/IP) is crossed to a normal stallion (n/Y), each conception has a 25% chance of being a normal filly (n/n), a 25% chance of being an affected filly (n/IP), a 25% chance of being a normal colt (n/Y), and a 25% chance of being an inviable male embryo (IP/Y).
