Researchers at Cornell University announced plans to conduct a new study focused on Lavender Foal Syndrome/Coat Color Dilution Lethal (LFS/CCDL). The project, led by Dr. Samantha Brooks and in collaboration with Dr. Doug Antczak and Don Miller at the Baker Institute for Animal Health, is funded in part by the Arabian Horse Foundation. The study seeks to locate the genetic marker(s) associated with LFS/CCDL and ultimately develop a diagnostic test to assist owners and breeders in identifying carrier breeding stock. To further develop this research project, assistance from the Arabian horse community is requested.
“This is exciting news for the Arabian horse community,” stated Beth Minnich, who chairs the newly formed Arabian Horse Association Task Force on Genetic Diseases. “Although LFS/CCDL foals are rare, it is a condition that has been of concern to breeders for decades. The Cornell study has made notable progress in a short amount of time, which is very encouraging. We are another step closer to our goal of having a genetic test developed for LFS/CCDL.”
Lavender Foal Syndrome (LFS) or more appropriately, Coat Color Dilution Lethal (CCDL), is a genetic disorder with neurological features thought to be caused by a brain lesion. An affected foal often has a difficult delivery (dystocia), cannot stand at birth and usually has episodes of tetany where the foal rigidly extends its limbs, neck and back.
LFS/CCDL foals are frequently born with a telltale diluted coat color that lightens the coat hairs, giving the foal an unusual appearance that can appear pale lavender, pale pink or even silvery, hence the name “coat color dilution” or “lavender foal.” The eye color has also been described as grayish-brown or having a bluish tint. Not all foals will have the unique coat coloration (although they may be paler than a normal foal) and if the coat color is overlooked or not present, foals may be misdiagnosed as having neonatal maladjustment syndrome (known as “dummy” foals) or some type of spinal cord injury.
Although unable to right itself, a LFS/CCDL foal may have a strong suckle reflex and may be bottle fed. However, these efforts are ultimately futile. Foals with LFS/CCDL, if they do not die, are euthanized (usually within a few days of birth) on humane grounds, as they are incapable of survival.
LFS/CCDL is relatively rare and the mode of inheritance has not yet been determined. However, it has been proposed by researchers to be an autosomal recessive trait (meaning that it is not sex linked and both parents must carry and pass along a copy of the mutated allele for an affected foal to be born; carrier horses are physically normal). There has also been some discussion that multiple genes may be involved. Some researchers have proposed a potential genetic relationship between LFS/CCDL and Juvenile Epilepsy Syndrome. It is important to note that while LFS/CCDL is often associated with Arabian horses of straight Egyptian or heavy Egyptian breeding, it has been reported in other Arabian breeding groups.
Using single nucleotide polymorphism (SNP) technology made available from the completion of the equine genome sequence, a small bank of samples from LFS/CCDL affected foals has been analyzed. The preliminary data from this testing shows some encouraging results. Additional testing needs to be conducted on a large number of horses to narrow down the possible markers.
To complete this work, and develop a test for LFS/CCDL, assistance from the Arabian horse community is needed. Because this process requires a large number of samples, Dr. Brooks is requesting samples from the following groups of horses:
- LFS/CCDL affected foals – special types of blood and tissue samples are needed. We strongly encourage any breeder/owner who has an affected foal born to contact Dr. Brooks for specific details on collecting and sending these samples.
- Family members of affected foals – hair samples from sires and dams of affected foals, along with siblings of affected foals.
- General Arabian horse population – hair samples from registered Arabian horses, regardless of bloodline.
All information, including the identity of submitted horses or participating farms, is kept strictly confidential.
For additional information, and to receive submission kits, please contact: Samantha A. Brooks, PhD
Assistant Professor, Department of Animal Science
Cornell University
129 Morrison Hall
Ithaca, NY 14867
phone: 607-220-6698/607-254-8217
e-mail: equinegenetics@cornell.edu
For additional information on the Arabian Horse Foundation or the LFS/CCDL project, please contact:
Beth Minnich, Chair, AHF Research Advisory Panel; Chair, AHA Task Force on Genetic Diseases – phanilah@aol.com
Larry Kinneer, President, Arabian Horse Foundation – larlv@aol.com