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

We estimated the allele frequencies of three variants of serum butyryl-cholinesterase, CHE1*U, CHE1*A and CHE1*F in an urban population of Santiago, Chile, resulting from a mixture of Amerindians with Europeans (mostly Spanish). The CHE1*A frequency was approximately that expected for this population but the incidence of CHE1*F was higher than previous studies would have predicted, probably because in this case more precise techniques were used for its detection. The finding of a CHE1 AK individual suggests that allele CHE1*K is also present at an appreciable frequency in this population.

A random sample of 140 individuals from the population of Valparaíso, Chile, was studied for 2 polymorphic genetic markers. The gene frequency estimates were: ACP*A = 0.246 +/- 0.026 and PGM1*2 = 0.235 +/- 0.025. The comparison of ACP with data obtained from other populations indicates a similarity with Mongoloid groups whereas for PGM1, the comparison with the data obtained shows no significant difference from Caucasoid populations. These results indicate that the Valparaíso population is the result of genetic admixture of various populations.

The distribution of glutathione S-transferase T1 (GSTT1) phenotypes was studied in a total sample of 673 Estonians whose four grandparents were born in Estonia, by an ELISA test able to differentiate between GSTT1 positive and GSTT1 negative phenotypes. 18% of the total sample did not present GSTT1-1 protein in whole blood. GSTT1-1 concentration was assayed in 519 out of the 552 GSTT1 positive subjects (i.e. 82% of the total sample) 49% percent of this subsample made up by 519 subjects was found to have GSTT1-1 in intermediate concentration and 33% in high concentration. The gene frequency of the GSTT1 deleted allele was estimated to be 0.423 as the square root of the frequency of the GSTT1 negative subjects (square root of 0.18 = 0.423) and that of the GSTT1 positive allele as (1-0.423) = 0.577. Statistically significant regional differences were found within the population with the lowest frequency of GSTT1 negative in western Estonia (9.5%) and the highest in the southeastern part of the country (24.5%).

The distribution of four serum complement component polymorphisms (BF, C2, C3 and C4) were examined in two geographically separated populations, one from Tasmania (Australia) and the other from northeast England. The differences in genotypic frequencies between them at all 4 loci are not statistically significant (p > 0.05). When C4 haplotypes were investigated, only one (C4A4-C4B2) exhibited significant linkage disequilibrium (p = 0.0006 after correction, p = 0.01), and this was only observed in Tasmanians. The English population exhibited a larger number of alleles across the four loci used in this study than the Tasmanian, and this may well reflect a bottle-neck effect and the greater relative isolation of the population of the island State of Australia. Overall, the findings confirm the close relationship between immigrants from the British Isles to Tasmania.

Historical studies on the Asiago Plateau have pointed to the peculiarity of its inhabitants in terms of their socio-cultural development marked by long periods of linguistic and cultural isolation. The present research on some serum protein markers (TF, GC and HP) aims to establish whether this isolation may have caused this population to become different from the others in terms of gene frequencies. For this purpose, transferrin (TF), group-specific component (GC) and human haptoglobin (HP) polymorphisms were studied in 435 subjects. GC and HP were found to be within the range of variation known for the Italian Peninsula.

Group specific component (GC), Haptoglobin (HP), Transferrin (TF), Caeruloplasmin (CP) and Albumin (Alb) plasma protein genes were studied in two endogamous Viswa subpopulations, the Viswa Brahmin caste and an artisan community (goldsmiths and carpenters) from Visakhapatnam (Coastal Andhra Pradesh, South India). No significant differences were found between the two subpopulations. The results were also compared with those available for other Andhra populations.

Alpha 2A-adrenergic receptor polymorphisms were investigated in 55 unrelated Caucasian Catalan individuals. Phenotypes were expressed by alpha 2-adrenoreceptor density and affinity determined by radioligand binding. In addition to the two previously described biallelic restriction fragment length polymorphisms (RFLP) (DraI and Bsu36I) [Hoehe et al 1988; Sun et al 1992], a transition was located in the promoter region of the human alpha 2A-adrenergic receptor using a non-radioisotopic single-strand conformational polymorphism (SSCP) analysis. DNA sequence analysis of this region showed that this transition produces the loss of a HhaI site. In our sample, the estimates of the frequency of this allele was 11% and those of DraI alleles were similar to those reported for other Caucasian populations but different from those observed in Afro-Americans. In addition, frequencies of the Bsu36I alleles in the Catalan population differed from those of Japanese and American White populations. A slight linkage disequilibrium between Bsu36I-DraI was found in our population. No association between phenotypes and RFLP genotypes was observed.

Allele and haplotype frequencies were determined for seven blood group genetic markers on a random sample of 366 individuals from two Georgian villages-Saberio and Alisubani. Genetic distance analysis shows that Georgians can be placed between the populations from the Northern Caucasian (West and Central) areas and the trans-Caucasian ethnic groups. An examination of the genetic relationship of Georgians with European and West Asian populations showed that Georgians are approximately equidistant from the groups compared.

The data available on the distribution of variants, phenotype and gene frequencies of different placental isoenzymes, especially for caste populations of Andhra Pradesh, are very scanty. In the present study, phenotype and gene frequency distributions of placental alkaline phosphatase (PLAP) of two caste groups namely, Lambada and Perika of Andhra Pradesh, South India, are reported. All the common phenotypes and the single case of a rare phenotype have been observed in the Lambada group.

A 21 year old woman from Thrace with clinical and laboratory findings of mild hemolysis, was found to be homozygous for haemoglobin O Arab. Blood samples from 15 members of her family and from 42 inhabitants of her village were examined for the presence of Hb O Arab. A high incidence of this variant allele was also detected among the patient's family members as well as in other inhabitants of the village (p = 0.274 +/- 0.049). The possibility that Pomaks, a culturally unique tribe with controversial ethnic origin, may represent one of the original pools for the geographic distribution of the gene in the broader area of the Mediterranean basin is discussed.