Human linkage maps - the same disease (genetic...

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

View Full Document Right Arrow Icon
Human linkage maps The size of the human genome is big enough that it took a long while to discover any evidence of genetic linkage. It was not until the 1950s that the first autosomal linkage groups were discovered. These all involved the polymorphic blood groups. One of the first was between one form of hereditary elliptocytosis (an anaemia caused by malformed erythrocytes) and the rhesus blood group . This study was important in showing that linkage information could prove the existence of more than one form of the same disease, it showed that there were some families in which the disease elliptocytosis was clearly linked to rhesus but that there were others in which it was not. This implies the existence of at least two genes which when mutant could cause
Background image of page 1
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: the same disease (genetic heterogeneity ). relationship to the human genome project It was not until the discovery of extensive inherited variation in DNA sequence which could be traced in families using Southern blotting or by PCR that human linkage studies really took off. It became possible to construct detailed genetic maps of the human genome which have provided a crucial skeleton of genetic landmarks onto which the human genome project is fitting DNA clones which will be sequenced. The detailed genetic map has made it now a matter almost of routine to position a genetic disease gene onto the genome map. This is the first stage in positional cloning , the normal route these days to identifying a disease gene....
View Full 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