Anthropological features of the CFTR gene: Its variability in an African population.
BACKGROUND
The CFTR gene (Cystic Fibrosis conductance Transmembrane Regulator) is the gene responsible for Cystic Fibrosis, the most common severe autosomal recessive disease in Europeans. It has been extensively explored in several European and European-derived populations, but poorly studied in the other major human groups.


OBJECTIVE
To characterize the variability of the CFTR gene in an African population.


METHODS
Using DGGE, all 27 exons (4443 bp) and 2184 bp of the flanking intronic regions of the CFTR gene were studied in a random sample of 45 Mossì from Burkina Faso (Western sub-Saharan Africa).


RESULTS
Sixteen variable sites were found: 13 SNPs (one in the promoter region, four non-synonymous and five synonymous in the exons and three in the introns) and three intronic STRs. Only the promoter site ( - 94 G/T), slightly polymorphic in the present survey, was not variable in different European populations. Comparison between Western Africans, Eastern Africans, Europeans and Eastern Asians showed that alleles at two intronic STRs (T(n) and (TG)(m) in intron 8), four exonic (M470V, 2694 T/G, 4002 A/G and 4521 G/A) and one intronic (875+40 A/G) SNPs have very different frequencies among at least two major human groups. Moreover, the overall degree of non-synonymous variability in Mossì is much lower than that in Europeans. A possible interpretation of this finding is proposed.


CONCLUSIONS
The CFTR gene has been since long hypothesized to have undergone selection in Europeans. The present study by comparing Africans and Europeans for the overall variability of the gene supports this hypothesis.
Maria Ciminelli
Bianca
B
Department of Biology, University of Roma-Tor Vergata, Italy. bianca.ciminelli@uniroma2.it
Bombieri
Cristina
C
Ciccacci
Cinzia
C
Belpinati
Francesca
F
Pompei
Fiorenza
F
Maselli
Roberta
R
Simporé
Jacques
J
Pignatti
Pier Franco
PF
Modiano
Guido
G
D000483:Alleles; D044383:Black People / Q000235:genetics*; D002050:Burkina Faso; D003550:Cystic Fibrosis / Q000453:epidemiology / Q000208:ethnology; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000235:genetics*; D005060:Europe / Q000453:epidemiology; D005091:Exons / Q000235:genetics; D005787:Gene Frequency; D006801:Humans; D007438:Introns / Q000235:genetics; D009154:Mutation; D020641:Polymorphism, Single Nucleotide; D011401:Promoter Regions, Genetic
D019005:Cystic Fibrosis Transmembrane Conductance Regulator