Genome Technique Identifies Diabetes Gene

There is a
letter published online at Nature, ahead of the
print version, that describes a technique of analyzing an entire genome
to find genes that may be associated with disease.



The newly-identified gene, in this case, is linked to Type 1 href="http://www.merck.com/mmhe/sec13/ch165/ch165a.html">Diabetes
Mellitus (T1D).  That is the type that usually
starts in childhood and always requires treatment with insulin.



The study was done by research teams in Canada and the USA.
 The gene they found is on the short arm of chromosome
(16p13).  There are two versions of the gene, Hakonarson said.
People with one version experience a 50% in risk for type 1 diabetes,
while those with the other do not have elevated risk.   href="http://en.wikipedia.org/wiki/Pfam">Pfam
prediction indicates that this gene probably encodes a protein with a
calcium-dependent lectin-binding
domain structure.  The study involved children of European
descent; it is not known how widespread the gene may be globally.

href="http://www.nature.com.proxy.lib.umich.edu/nature/journal/vaop/ncurrent/abs/nature06010.html">

href="http://www.nature.com.proxy.lib.umich.edu/nature/journal/vaop/ncurrent/abs/nature06010.html">A
genome-wide association study identifies KIAA0350 as a type 1 diabetes
gene

Nature advance online publication 15 July 2007

doi:10.1038/nature06010

Type
1 diabetes (T1D) in children results from autoimmune destruction of
pancreatic beta cells, leading to insufficient production of insulin. A
number of genetic determinants of T1D have already been established
through candidate gene studies, primarily within the major
histocompatibility complex but also within other loci. To identify new
genetic factors that increase the risk of T1D, we performed a
genome-wide association study in a large paediatric cohort of European
descent. In addition to confirming previously identified loci, we found
that T1D was significantly associated with variation within a 233-kb
linkage disequilibrium block on chromosome 16p13. This region contains
KIAA0350, the gene product of which is predicted to be a sugar-binding,
C-type lectin. Three common non-coding variants of the gene (rs2903692,
rs725613 and rs17673553) in strong linkage disequilibrium reached
genome-wide significance for association with T1D. A subsequent
transmission disequilibrium test replication study in an independent
cohort confirmed the association. These results indicate that KIAA0350
might be involved in the pathogenesis of T1D and demonstrate the
utility of the genome-wide association approach in the identification
of previously unsuspected genetic determinants of complex traits.

Clearly they do not know what the gene does, but they propose this
hypothesis:

Studies
are underway to characterize the functional role of KIAA0350. In light
of the crucial role of the MHC genetic repertoire in antigen
presentation involving sugar groups, such as lectin, we hypothesize
that a genetic variant in the binding site for such a molecule on the
activating cytotoxic T-cell could elicit an autoimmune response that
results in the destruction of the islet cells of the pancreas, as seen
in T1D.

News wires are humming about this:

href="http://www.lse.co.uk/ShowStory.asp?story=UR1639712M&news_headline=scientists_identify_childhood_diabetes_gene">Scientists
Identify Childhood Diabetes Gene

Life Style Extra, UK

A gene that causes diabetes in children has been identified by
scientists - boosting the chances of preventing the condition in the
future. ...



href="http://www.canada.com/topics/news/story.html?id=a37366d6-d1a6-489e-97dc-e90eb3c67895&k=94695">Key
gene identified in type 1 diabetes

Canada.com, Canada

WASHINGTON - Scientists have pinpointed an important gene involved in
increasing a child’s risk for type 1 diabetes, a discovery
they said may lead to a way to prevent the development of the disease...

I read the whole thing and did not see anything to suggest that the
authors expect to be able to prevent diabetes.  Perhaps that
speculation was offered in a press release or an interview.
 In the actual publication, their emphasis is on the utility
of the method they used to find the suspect gene.