Saturday, August 06, 2005

The Genetics of Type 1 Diabetes, by Hsien Hsien Lei

Lei has kindly written this article for the blogathon. She has also written a post on her blog about me, my diabetes related activities and my struggle with diabetes. Lei's blogs include her Genetics and Public Health Blog (where the posts about diabetes are) and her Cotton Pickin' Days personal blog. If you go by her Genetics blog, be sure to check out the article on how humans are genetically similar to pigs!

The Genetics of Type 1 Diabetes
by Hsien Hsein Lei

Type 1 diabetes occurs when the insulin-producing cells of the pancreas are destroyed by the body's own immune system. About 18 regions of the genome, labeled IDDM1 to IDDM18, have been associated with an increase in type 1 diabetes risk.

  • IDDM1 - HLA genes that encode immune response proteins

  • IDDM2 - insulin gene

  • IDDM4 - genes for ZFM1 (zinc finger protein 162), FADD (Fas-associated death protein), and LRP5

  • IDDM5 - SOD2 gene

  • IDDM6 - gene associated with colorectal cancer (DCC), gene that encodes a zinc finger DNA binding domain (ZNF236), and a molecule that opposes apoptosis (bcl-2)

  • IDDM7 - genes for NEUROD1, IGRP

  • IDDM10 - GAD2 gene

  • IDDM11 - genes for ENSA and SEL1L

  • IDDM16 - gene that encodes for immunoglobulin heavy chain

  • IDDM18 - ILB12 gene

  • CTLA4 gene - regulates immune system

  • CD28 gene

  • ICOS gene

Despite these and other candidate genes that have been associated with increased risk of type 1 diabetes, no gene therapy or gene-targeted drugs have been developed thus far. As more genes are discovered and their functions better understood, it will become possible to figure out exactly why some people have type 1 diabetes and to provide them a cure, as well as prevent others from developing it in the first place.

For more detailed information, see The Genetic Landscape of Diabetes, NCBI


Lei said...

I'm glad you were able to use what I wrote for your post! It only touches the surface, but hopefully gives people some hope. :) Now, only 44 posts to go? Go , Candice. GO! ;)

Patty said...

I'm a little slow. :) Does this mean that if you have these 18 regions, there's a greater likelihood you will develop Type 1 but you may not?

Candice said...

Patty, I don't think you have ALL of them. I think you need to ask Lei. I'm sure she will answer.

Lei said...

Good morning! It's just past 8 a.m. Sunday here in Vietnam.

Patty, you're not slow. My blurb just didn't include enough background information! Both type 1 and type 2 diabetes are caused partly by genes and partly by environment. For type 1 diabetes genes I mentioned, if you have one or more of the genes in those 18 chromosomal regions or other genes that have been identified, your risk of type 1 diabetes it theoretically higher. There are so many risk factors for diabetes, both genetic and not, that it's hard to tell exactly who will develop type 1 and who will not. There still needs to be a lot of research before any kind of genetic testing can tell someone their risk of developing diabetes.

Hope this helps. :)

Patty said...

It does help! Thank you for explaining it!