GeneChat

Huntington's Disease

I have Homozygous on the HTT genes;
rs362272 - AA
rs362273 - GG
rs362331 - CC
rs363092 - AA
rs6855981 - AA

How can you tell if there is a chance you can develop the disease? I have a lot of symptom and my grandfather on my moms side died early of many of the issues listed as being caused by the disease. He died in 1987 so long before there was ever genetic testing to find out what was wrong with him.

None of these variants will cause Huntington’s. The HTT gene contains a region where the letters the letters CAG are repeated multiple times. This is called a trinucleotide repeat. Most people will have between 10 and 35 repeats. People who develop Huntington’s have 36 or more repeats. A different type of DNA test is needed to test for this condition.

Huntington’s Disease is not known to skip generations. If your mother does not have it, you will not either. There are a number of genetic conditions along the DNA strand that Huntington’s is on, such as Parkinson’s, Multiple Sclerosis etc. Your grandfather may have had something like that. Genetic testing for HD was finalized in about 1985 so, if he hadn’t had the DNA test, it would have only been if your grandfather had an autopsy that HD would have been identified. There are Huntington Disease Family groups around the world. You might try contacting one of them if you are still concerned.

@austex One can develop Huntington’s if neither parent has it. In some instances the trinucleotide repeat expands when it is passed onto the next generation.

The expansion of the trinucleotide repeat is also why a child may have a more severe form of the condition than their parent.