HHT in Wikipedia

I found even Wikipedia has some articles on it.

see wikipedia (http://en.wikipedia.org/wiki/Hereditary_hemorrhagic_telangiectasia)

This one talks a bit about the genetics of it, and goes through the autosomal dominant part of the genetics.

I wonder if this makes sense to anyone:

• Autosomal dominant gene

• An autosomal dominant gene is one that occurs on an autosomal (non-sex determining) chromosome. As it is dominant, the phenotype it gives will be expressed even if the gene is heterozygous. This contrasts with recessivehomozygous to be expressed.

• The chances of an autosomal dominant disorder being inherited are 50% if one parent is heterozygous for the mutant gene and the other is homozygous for the normal, or 'wild-type', gene. This is because the offspring will always inherit a normal gene from the parent carrying the wild-type genes, and will have a 50% chance of inheriting the mutant gene from the other parent. If the mutant gene is inherited, the offspring will be heterozygous for the mutant gene, and will suffer from the disorder. If the parent with the disorder is homozygous for the gene, the offspring produced from mating with an unaffected parent will always have the disorder. See Mendelian inheritance.
• The term vertical transmission refers to the concept that autosomal dominant disorders are inherited through generations. This is obvious when you examine the pedigree chart of a family for a particular trait. Because males and females are equally affected, they are equally likely to have affected children.
• Although the mutated gene should be present in successive generations in which there are more than one or two offspring, it may appear that a generation is skipped if there is reduced penetrance.

• Autosomal Dominant Pedigree Chart

! I never knew I could paste graphics into a blog - see you learn something new every day!!!

This is an interesting chart from wikipedia - it shows anyone with the "half" a gene has it.




It is also very interesting that they are only just starting to identify the chromosomes that it affects - Four forms have been described.

The wikipedia article in interesting - it quotes a different rate of occurance:-

• Epidemiology

• HHT occurs mainly in whites (1:5,000), more in certain areas of France, but much less in blacks (1 in 1 million). It is found in all continents throughout the world. It is also seen with increased frequency in Mormon families from Utah.

Interesting.........