TaqI digestion of PCR product increases the informativity of St14 VNTR for the diagnosis of hemophilia A.
Recently, a pair of PCR primers have been described that make it possible to amplify a highly polymorphic VNTR locus DX552 (St14). PCR products range in size from approximately 650 to 3000 bp. Ninety X chromosomes from unrelated Caucasian subjects were investigated. Digestion of the PCR products with TaqI revealed the presence of a polymorphic TaqI restriction site within the product 200 bp from the end. This restriction site is present on 60% and absent on 40% of all alleles, but the absence is confined solely to the alleles 1690 bp (39%) and 2100 bp (1%). Thus, there is a strong allelic association between the most frequent 1690 bp allele and the absence of the TaqI restriction site. Determination of this polymorphisms within the St14 VNTR region increases the expected heterozygosity at the DXS52 locus from 72% to 80%. This increases the fraction of hemophilia A families where this marker is informative for indirect prenatal diagnosis and carrier identification.
Saksova
L
L
Institute of Molecular Physiology and Genetics, SAS, Bratislava, Slovakia.
Gecz
J
J
Kadasi
L
L
Ferak
V
V
D001483:Base Sequence; D002874:Chromosome Mapping; D004259:DNA-Directed DNA Polymerase; D006467:Hemophilia A / Q000175:diagnosis*; D006801:Humans; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D019914:Taq Polymerase; D014960:X Chromosome
D019914:Taq Polymerase; D004259:DNA-Directed DNA Polymerase