Direct molecular haplotyping of multiple polymorphisms within exon 4 of the human catechol-O-methyltransferase gene by liquid chromatography-electrospray ionization time-of-flight mass spectrometry.
The applicability of ion-pair reversed-phase high-performance liquid chromatography hyphenated to electrospray ionization time-of-flight mass spectrometry (ICEMS) for the haplotyping of five SNPs (rs769223, rs4818, rs4986871, rs8192488, rs4680) located within exon 4 of the human catechol-O-methyltransferase (COMT, EC 2.1.1.6) gene is demonstrated. Two differently sized products of polymerase chain reaction--a 71-bp amplicon partially covering the sequence of a 124-bp amplicon--were used to determine unequivocally the allelic states of the single nucleotide polymorphisms linked on both chromosomes. The two amplicons were co-loaded onto the chromatographic column and simultaneously analyzed within a single gradient run. Using the described strategy, 101 individuals representing an Austrian population sample were typed. The obtained haplotype frequencies will serve as reference values in future association studies to examine the impact of the COMT gene on neuropsychiatric disorders. Additionally, two newly discovered polymorphic sites within the sequence of the COMT gene are described (a synonymous C>T mutation at the third position of the amino acid codon 99 in the soluble COMT protein or 149 in the membrane-bound COMT protein; a non-synonymous G>A substitution at the second position of the amino acid codon 95 in the soluble COMT protein or 145 in the membrane-bound-COMT protein).
Oberacher
Herbert
H
Institute of Legal Medicine, Innsbruck Medical University, Muellerstrasse 44, 6020, Innsbruck, Austria, herbert.oberacher@i-med.ac.at.
Pitterl
Florian
F
Niederstätter
Harald
H
Weiss
Elisabeth M
EM
Stadelmann
Edith
E
Marksteiner
Josef
J
Parson
Walther
W
D001483:Base Sequence; D002394:Catechol O-Methyltransferase / Q000235:genetics*; D002853:Chromatography, Liquid / Q000379:methods; D004247:DNA / Q000032:analysis* / Q000235:genetics / Q000302:isolation & purification; D005091:Exons; D005260:Female; D006239:Haplotypes; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D012680:Sensitivity and Specificity; D017422:Sequence Analysis, DNA; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D013997:Time Factors
D004247:DNA; D002394:Catechol O-Methyltransferase