title: Frequencies of promoter pentanucleotide (TTTTA)n of CYP11A gene in European and North African populations.
abstract: The present work attempts to determine the distribution of CYP11A (TTTTA)n genotype and allele frequencies in 10 European and North African populations. This polymorphism has been associated with hyperandrogenism by several association studies. To our knowledge, this is the first study investigating the ethnic variation of this polymorphism. DNA was extracted from 868 whole-blood samples with the standard phenol-chloroform technique, and PCR reactions were carried out using fluorescent primers as described previously. PCR products were analyzed by an ABI 3,730 DNA Analyzer. A total of six alleles were identified, ranging from 220 bp (4 repeats [4R]) to 250 bp (10R). The most frequent allelic fragment size in all populations was 4R, with frequencies ranging from 47.9% (Sicily) to 62.8% (Tuscany and Germany). Allelic frequencies showed high heterogeneity between analyzed populations. We detected a significant gradient for alleles 4R and 8R. In this study, we report the allele frequency distribution of CYP11A (TTTTA)n showing a north-south geographic gradient. This result could be useful for epidemiological studies about hyperandrogenism.
authors.affiliation: Department of Experimental Biology, University of Cagliari, Cagliari, Italy.
authors.forename: Ignazio
authors.initials: I
authors.lastname: Piras
authors.forename: Alessandra
authors.initials: A
authors.lastname: Falchi
authors.forename: Pedro
authors.initials: P
authors.lastname: Moral
authors.forename: Alessandra
authors.initials: A
authors.lastname: Melis
authors.forename: Laurianne
authors.initials: L
authors.lastname: Giovannoni
authors.forename: Giorgio
authors.initials: G
authors.lastname: Paoli
authors.forename: Carla
authors.initials: C
authors.lastname: Calò
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Vona
authors.forename: Laurent
authors.initials: L
authors.lastname: Varesi
mesh_terms: D000352:Africa, Northern; D000483:Alleles; D001483:Base Sequence; D002786:Cholesterol Side-Chain Cleavage Enzyme / Q000235:genetics*; D017931:DNA Primers / Q000235:genetics; D005060:Europe; D005260:Female; D005787:Gene Frequency; D006801:Humans; D017588:Hyperandrogenism / Q000201:enzymology / Q000235:genetics; D008297:Male; D018895:Microsatellite Repeats; D011110:Polymorphism, Genetic; D011401:Promoter Regions, Genetic
chemical_list: D017931:DNA Primers; D002786:Cholesterol Side-Chain Cleavage Enzyme