Gene geography : a computerized bulletin on human gene frequencies最新文献

This study was conducted on the Saudi population from different regions of Saudi Arabia to determine the frequency of sickle cell gene (Hb S). The results revealed that Hb S was present in most of the regions though at significantly variable frequencies. The highest frequency (0.149) was found in Al-Qateef, an eastern province of Saudi Arabia, and the lowest (0.001) were found in the central region. In some areas a close correlation was evident between malaria endemicity and Hb S gene frequency although a low frequency was encountered in some malaria endemic regions.

Three-hundred and thirty placental samples from two caste populations of Andhra Pradesh, South India, were screened by electrophoresis for the variants of acid phosphatase and for the phenotypes of alkaline phosphatase. Only the six common phenotypes of alkaline phosphatase were detected; no variants of acid phosphatase were found.

This paper reports PCR-based genotype distribution and allele frequencies of the locus HumFES/FPS (human c-fes/fps proto oncogene). For this study 300 unrelated Caucasoids of German ancestry living in Düsseldorf were analyzed. Seven of the eight alleles previously described and fourteen of the corresponding thirty-six diploid genotypes were detected. The proportions of heterozygotes and homozygotes observed and expected and the parameters of forensic interest, e.g. the mean paternity exclusion chance, were calculated. No deviations from the Hardy-Weinberg equilibrium were observed. A preliminary German data base (3,238 individuals) was created by using the weighted arithmetical mean which included data from Düsseldorf.

Genotype and allele frequencies at seven Variable Number of Tandem Repeats (VNTR) loci currently used for forensic purposes have been estimated in a population sample from Calabria (south Italy). DNA target regions relevant to four microsatellites (THO.1; REN.4; D12S67; DYS19) and three minisatellites (D1S80; 3'APOB; TPO.10) were amplified by Polymerase Chain Reaction (PCR) and analysed by electrophoresis and ethidium bromide or silver staining. For all loci, the observed genotypes were found to be in agreement with those expected by the Hardy-Weinberg equilibrium. Data on allele frequencies were in line with those found in sample groups from northern or central Italy, tested for some of the above polymorphisms.

PI phenotypes were determined by isolelectric focusing in a Venezuelan mixed population (the center point of the geographical area investigated being Apartaderos, State of Mérida, Venezuela). Six alleles were found, four normal and two risk-predisposing with the following frequencies: PI*M1 (80.5%), PI*M2 (7.0%), PI*M3 (6.2%), an anodic allele here referred to as PI*"AN' (0.2%), PI*S (5.0%) and PI*Z (0.9%). The latter, unlike the others, was found only in 10% of the area considered, where it had a polymorphic frequency of 2.1%, reflecting a probable geographic isolation and/or a cultural influence in mating choice. In this population the alleles predisposing to risk are most probably of Caucasoid origin ("Spanish' genes). The PI*Z and PI*S frequencies may be attributed to random genetic drift characterized by an important founder phenomenon and to population admixture (Amerindian and Spanish), respectively. The PI*S allele may be considered a very good marker for the Caucasoid contribution to the overall mixed population of Venezuela.

The population of 26 Albanian districts were analysed for AB0, MN and Rhesus blood group systems. The dendrogram based on genetic distances showed a closer relationship between districts with a higher population density and a higher gene flow. It was shown that, of all Balkan populations, the most closely related were those from Slavic areas and that the Albanian population was the most distinct.

PGP electrophoretic polymorphism was studied in a sample of 548 blood donors from the province of Bologna, Italy. Haemolysates were typed by thin starch-gel electrophoresis, a modification of Barker and Hopkinson's method [1978]. The distribution of PGP phenotypes and gene frequencies in Italy varies considerably. The pattern observed in the Bologna sample agrees with the data from northern Italian regions and comparisons show that PGP*2 and PGP*3 gene frequencies tend to decrease along a north-south cline. Sardinia shows a peculiar distribution of gene frequencies where the PGP*2 allele is very low and the PGP*3 allele is absent. The world PGP gene frequencies appear to be distributed along a north-south cline.

Of the three major Afrikaner founder mutations, responsible for more than 95% of Familial Hypercholesterolemia cases among South African Afrikaners, one mutation called V408M or FHAfrikaner-2 was identified in the Netherlands. Subsequent analysis of a group of Canadian patients of Dutch origin with Familial Hypercholesterolemia revealed the presence of this mutation in western Canada. The founder of the Canadian family, suffering from Familial Hypercholesterolemia caused by V408M, was traced back to Andijk, a small village in the northwestern part of the Netherlands, a region from where the first settlers to South Africa departed in the 17th and 18th century. Further genealogical investigation demonstrated that the mutation must have been introduced in the Netherlands by an individual from northern Germany. Haplotype analysis resulted in the identification of the common haplotypes TaqI-, StuI+, AvaII+, NcoI+ in Canadian as well as Dutch patients with V408M. The results of this study further support the hypothesis that Dutch settlers introduced this Afrikaner founder mutation in the Afrikaner population in South Africa. After a recombinational event in the mutated gene, the mutation was also introduced in western Canada.

The allelic frequencies of 14 polymorphic loci were obtained for the Paisa community (Antioquia, Colombia) and compared with those of Caucasoids, Negroids and Amerindians as an approach to better understand its ancestral origin. Data pertaining to Caucasoids included Basques, Spaniards and Jews, historically assumed to be the ancestors of Paisas. These comparisons suggested that the Paisa community is a Caucasoid group with very low Amerindian or Negroid contributions. Spaniards or Basques and, to a lesser extent, Sephardims seem to have been their most probable ancestors.

This paper presents allele frequencies of two short tandem repeats (CD4 and F13A1) in three anthropologically defined populations: Sardinians (Italy), Corsicans (France) and Piaroa Indians (Venezuela). The comparison shows some relevant differences both in number and distribution of the CD4 and F13A1 alleles.