The team from Bannasch Laboratory were involved in the recent 10th International Equine Genome Mapping Workshop held 10-13 July 2013 at the Biotechnology Centre of Azores from the University of Azores.
The First
International Equine Gene Mapping Workshop sponsored by the Dorothy
Russell Havemeyer Foundation (DRHF) was conducted in 1995 in Lexington,
Kentucky. Since then, a series of horse genome workshops were conducted
by the DRHF every two years (San Diego, California; 1997; Uppsala,
Sweden; 1999; Brisbane, Australia; 2001; Kreuger Park, South Africa;
2003; Newbridge, Ireland; 2005; Tahoe City, California; 2007; Ickworth,
Suffolk, United Kingdom; 2009; Chaska, Minnesota; 2011).
Over
200 scientists from 20 countries around the world have been
participating in these workshops, sharing ideas and resources,
collaborating and creating a common genomics framework.
The Bannasch submission is as follows:
10th Dorothy Russell Havemeyer
Foundation International Equine Genome Mapping Workshop Abstract
A successful genome wide association for Connemara Hoof Wall Separation
Syndrome using the equine Illumina 74K beadchip
Danika Bannasch, Carrie Finno,
Carlynn Stevens, Amy Young, Sheila Ramsay
A syndrome has
been described in Connemara foals characterized by severe separation of the
hoof wall during the first year of life.
Clinical signs of HWSS occur when the weight-bearing borders of the hoof
wall break away from the underlying structure, leaving the pony to bear weight
on the sole of the hoof and unfit for riding.
Initial pedigree research has revealed a likely hereditary component to
the disease with an apparent autosomal recessive mode of inheritance. DNA samples, pedigrees and photographs were
collected from Connemara ponies from around the world. Within a year, 15 affected individuals and
315 controls were sampled. Twelve cases
and 24 controls were genotyped on the Illumina Equine 74K beadchip. Based on our results, 12 affected and 24
unaffected cases provided significant power to identify a strong, genome-wide
significant, candidate region of association (p raw 6.9 X 10-11, p
genome 2.6 X 10-5).
Three additional affected foals and 5 obligate carriers were
subsequently genotyped. A region of
homozygosity of 1.8 Mb was identified in all 15 affected foals consistent with
an autosomal recessive mode of inheritance. Next generation sequence data from
affected ponies and controls across the region will be analyzed for mutations
and the results reported at the meeting.
The take home message from the information in the above abstract is that:
The take home message from the information in the above abstract is that:
- There is NO DOUBT WHATSOEVER that HWSS is genetic in origin.
- There is NO WAY that the above abstract would have been accepted for this workshop if the work being presented was not proven beyond all doubt.
- HWSS is NOT the result of 'mineral imbalance', any other environmental challenge or lack of care of the part of owners of affected ponies.
- HWSS is the result of mating two ponies who carry a genetic mutation.
Denial that the cause of this condition is genetic is not going to make the problem disappear; indeed based on present trends the incidence of HWSS in the Connemara pony population is set to increase.
A population genetics study presently underway, indicates that this is especially so in Ireland; a direct result of overuse of certain stallions both historically and in the present.
A population genetics study presently underway, indicates that this is especially so in Ireland; a direct result of overuse of certain stallions both historically and in the present.
