Single Nucleotide Polymorphisms involved in Haemophilia

A single point substitution of the "C" at position 6460 of the clotting factor IX gene for a "T" causes haemophilia . This is because this mutation is a nonsynonymous substitution, which means the alteration of the nucleotide affects the encoded amino acid at that position. The "C" lies in the codon "CGA", which encodes for an amino acid arginine (Arg). Changing this sequence to "TGA" alters the meaning of the codon to a terminator in the protein coding sequence. In this case, an individual with this sequence will not make any clotting factor IX. This means that the blood clotting process fails which can cause haemophilia.

other e.g. of SNP=>Coronary Heart Disease and Debrisoquine Metabolism