LWO gene

Question
Hi Lisa,
I badly want a black and white frame overo.  There are no black and whites, only red and white in the Missouri Foxtrot breed, therefore I have to breed the black color in.  My question is:  Am I correct in the thinking that ALL overo's do NOT carry the LWO gene?  My stud is red and white and has a copy of the LWO gene.  Can I find a spotted homozygeos for black overo that does not carry the gene or not?  I think it's a common misnomer that ALL overo patterned horses are carriers.  Am I right or wrong?

Answer
Hi Mercedes,
              UC Davis say that there is only one gene that is responsible for producing the lethal white syndrome, and that gene is associated with horses that carry the overo paint gene.

When two white patterned horses carrying the gene (heterozygous arriers) are bred, there is a 25% chance that the foal will be conceived with a copy of the mutation from each parent, making him homozygous for the condition.

They usually happen when an Overo mare is bre to an Overo stallion. Studies do show that frame overos, highly white overos, and frame blend overos do carry the highest chance of throwing a Lethel White foal.

There are though a small percentage of overo-patterned horses that do not carry the gene .

Before you breed, you should have both the mare and stallion checked for  the LWO gene.

I hope this helps.

Lisa