What makes a mutation dominant

What makes a mutation dominant - What makes a mutation...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
What makes a mutation dominant? Haploinsufficiency. In this case, the amount of product from one gene is not enough to do a complete job. Perhaps the enzyme produced is responsible for a rate limiting step in a reaction pathway. Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant vascular dysplasia leading to telangiectases and arteriovenous malformations of skin, mucosa, and viscera. Death by uncontrollable bleeding occasionally occurs. It is caused by mutation in the gene ENG , which codes for the protein endoglin, a transforming growth factor- beta (TGF-beta) binding protein. Perhaps the TGF-beta is unable to exert sufficient effect on cells when only half the normal amount of receptor is present. Dominant negative effect. The product of the defective gene interferes with the action of the normal allele. This is usually because the protein forms a multimer to be active. One defective component inserted into the multimer can destroy the activity of the whole
Background image of page 1
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 11/22/2011 for the course CHEMISTRY CHM1025 taught by Professor Laurachoudry during the Fall '10 term at Broward College.

Ask a homework question - tutors are online