Appendix

Parentage/Genetic Marker Report

This DNA-based parentage test uses microsatellite marker analysis to compare the DNA profile of an offspring to the profiles of possible parents.

Horse Embryo Pre-Implantation Genetic Diagnosis

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.

Immune-Mediated Myositis (IMM/MYH1)

Immune-mediated myositis (IMM) is an autoimmune muscle disease that can result in severe atrophy and extreme muscle loss. The genetic susceptibility to this condition is found in quarter horses and quarter horse-related breeds.

Hereditary Equine Regional Dermal Asthenia (HERDA)

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.

Tobiano

Tobiano is a white spotting pattern characterized by white on the body that crosses the topline.

Roan Zygosity Test

Roan is a white patterning coat color trait characterized by intermixed white and colored hairs in the body while the head, lower legs, mane, and tail remain colored.

Red Factor

The extension gene, or red factor, determines whether a horse will have a chestnut base coat color or a black or bay base coat color.

Gray

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.

Dominant White Mutations – W5, W10, W20, and W22

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.