You are a geneticist and through careful analysis of a large

You are a geneticist and through careful analysis of a large family with migraine headaches have determined that the disorder is linked to a previously cloned gene, X, which lies on chromosome 14. You set out to identify the polymorphism in gene X that confers susceptibility to migraine. You isolate DNA from a family member who suffers from migraine, amplify the DNA using gene-specific primers and polymerase chain reaction, and clone it into a plasmid. You then sequence the gene and, indeed, find a single nucleotide polymorphism that causes a missense mutation within one of the exons. Can you conclude that it is responsible for conferring susceptibility to migraine?

Solution

Missense mutation is a point mutation in which a single nucleotide change results in a codon that codes for a different amino acid. When DNA(exon, which is coding region) is isolated and sequenced shows missense mutation,means first it codes for protein which does not cause migraine but due to mutation it codes different amino acid(I.e. different protein ).
Missense mutations gene X of chromosome 14 cause migraine. Mutant proteins cDNAs were quantified and characterized, in an attempt to determine which aspect of enzyme function was affected by specific mutation.