Patent ID: 8163480

Claim:
A method of detecting a mutation in a tandem repeat segment of a gene in a human genomic nucleic acid sample comprising a nucleic acid segment and a marker sequence, wherein said mutation is characterized by a change in the number of repeats compared to the number of repeats in the wild type allele, said method comprising a) fragmenting the nucleic acid sample into fragments, wherein said tandem repeat segment is associated with a marker sequence in at least one of said fragments; b) separating said fragments from a) into liquid fractions according to size under conditions in which the fragment(s) containing the tandem repeat segment will be located in said liquid fractions according to the number of repeats in the tandem repeat segment; c) subjecting said fragments from said one or more liquid fractions of b) to a second fragmentation such that all or a portion of the segment is cleaved from said marker sequence; d) identifying the segment by amplifying and detecting the marker sequence within said one or more liquid fractions from c), wherein the number of repeats in the tandem repeat segment is determined by the liquid fraction in which it is identified in b), and e) comparing the number of repeats in the tandem repeat segment determined in d) to the number in the corresponding wild type allele, wherein a number of repeats differing from the number in the wild type allele is indicative of a mutation.