Implications of a common polymorphism in intron 12 of the dystrophin gene for deletion detection by multiplex PCR.
The multiplex polymerase chain reaction (PCR) is a reliable and efficient method for detecting dystrophin gene deletions in about 65% of patients with Duchenne or Becker muscular dystrophy (DMD or BMD). The 9-plex PCR assay, which simultaneously amplifies the muscle-specific promoter and exons 3, 6, 13, 43, 47, 50, 52 and 60, is one of the multiplex PCR assays used routinely to test for DMD and BMD deletions. In this study, we describe a previously unrecognized A to G base variation in intron 12 (nt -110 from exon 13) of the dystrophin gene. This variant, located within the annealing site of the exon 13 forward primer, prevented amplification of exon 13 in the 9-plex PCR assay. Present in 56% (25 of 45) of normal Caucasian alleles and 23% (3 of 13) of normal black American alleles, it is likely encountered frequently during dystrophin deletion analysis by multiplex PCR, and may complicate test result interpretation. Therefore, we suggest two modifications for the multiplex PCR detection of dystrophin gene deletion.
Chen
B
B
Molecular Diagnosis Laboratory, Arkansas Children's Hospital, 800 Marshall Street, Little Rock, AR 72202, USA. bchen@exchange.uams.edu
North
P E
PE
Parham
D M
DM
D000483:Alleles; D001483:Base Sequence; D044383:Black People / Q000235:genetics; D016189:Dystrophin / Q000235:genetics*; D005091:Exons; D005787:Gene Frequency; D014644:Genetic Variation; D006801:Humans; D007438:Introns; D008297:Male; D018482:Muscle, Skeletal / Q000378:metabolism; D009136:Muscular Dystrophies / Q000235:genetics*; D017354:Point Mutation; D016133:Polymerase Chain Reaction / Q000379:methods; D011110:Polymorphism, Genetic; D011401:Promoter Regions, Genetic; D012016:Reference Values; D017384:Sequence Deletion; D014481:United States; D044465:White People / Q000235:genetics; D001741:Black or African American
D016189:Dystrophin