Personal Genetics

Time for a ‘sciency’ post. Why now? Well I recently found that we have a hereditary genetic mutation in the family which manifests as the condition called hereditary haemorrhagic telangiectasia (HHT) or Osler-Weber-Rendu syndrome.

Heamaawhat? you may ask yourself.

Its a condition which results in the failure of angiogenesis ( blood vessel formation) in certain blood vessel populations in specific tissues. They lack capillary beds and as a result arteries directly flow into veins [ called arteriovenous malformations ]. This creates a very high pressure environment that causes vessel rupturing. These ruptures can occur throughout the body including the skin, GI tract, lungs, liver and brain. Despite being autosomal dominant sufferers exhibit a range in severity. Also not all tissues develop these symptoms/ manifestations for reasons not totally evident. With regard to its prevalence HHT occurs in 1in 5,000 to 1 in 10,000 people.

The two main forms of HHT are due to mutations in the endoglin (HHT1) or activin like kinase 1 (HHT2) genes. Both of these genes/proteins are components of the TGF Beta signalling network, a pathway critical for endothelial cell (blood vessel cells) function.

After my father was formally diagnosed with HHT and his mutation identified off went our (my brother’s and mine) DNA to the Netherlands to get checked out. Now you would think this would only take a few weeks right? I mean this is something that I could do in my own lab after all. Nope! We only just received the results. A several month process ! Why couldn’t this simple service be performed in NZ?

Anyhow ….. the results? Well I do not carry the mutation but my brother does. Like with all things of this nature it is best that you know now that you have the disorder to allow for precautionary measures to be taken to prevent future deleterious events. So the next thing on the agenda is for my brother to undertake the various scans for these AVMs in various organs and also to get my cousin screened for the mutation. Studying genetics throughout my university career it is quite surreal that I have such an example in my own backyard per se.

My attempt at a pedigree analysis for my father side.

hht

On a similar note, this area of personal genetic testing is hotting-up with many companies now offering testing services costing <$400 such as 23andme.com, pathway.com, dnaancestryproject.com and dnadirect.com. They seek to unlock the mystery of ancestries and provide information about your health specifically your susceptibility to various ailments and diseases. Much debate has been raised surrounding the unbalance between the informative capacity of the results and what is promised/claimed through advertising.

Likewise we have also seen the cost of sequencing dramatically decline with recent reports claiming that whole genome sequencing now only costs $50,000. With advances like this being made more frequently, such personal testing services will soon become the norm.

While in San Francisco recently I saw my first blimp. Guess what was being advertised on the side of it? www.23andme.com.

CIMG1418

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Graeme @ graemefielder.com

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One response to “Personal Genetics

  1. Glad to hear that your brother is in the process of being evaluated for necessary precautions and treatments. Now that the family’s gene is identified, everyone else should be tested, and the cost is greatly reduced once the gene is known.

    I have been searching blogs to find people interested in HHT. Our family has been greatly impacted by this little-known disease, and after years of feeling helpless and hopeless, we’ve seen drastic improvement thanks to the work of the HHT Foundation and the health-care professionals at the HHT Centers of Excellence worldwide. My husband has gone from a hemoglobin of 6.4 to well over 16! He is able to walk and jog, feels optimistic and almost never has a nosebleed after months of projectile bleeding, blood transfusions, iron infusions and multiple procedures all due to HHT. For information about the latest advances in HHT, go to the Foundation’s web site: http://www.hht.org

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