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

HLA class II gene frequencies were analysed in a panel of 101 unrelated individuals with Piedmontese ancestors living in Piedmont (north western Italy). A class II genomic typing was performed using the XI Histocompatibility Workshop protocol based on locus specific amplification by Polymerase chain Reaction (PCR) of class II gene second exon and hybridization with sequence specific oligonucleotides (SSO). Compared to other HLA typing techniques, this protocol defines more class II subtypes and analyses HLA-DP gene polymorphisms. The frequencies of alleles at DRB1, DRB3, DRB4, DRB5, DQA1, DQB1, DPA1, DPB1 loci are reported. Linkage disequilibrium analysis between DPA1-DPB1 and DRB1-DPB1 alleles is also reported.

The beta s cluster haplotypes were determined for 74 Brazilian patients with sickle cell anemia from three cities separated by 1,400 to 2,300 km. The cities are representative of the regions which have the largest Black populations of the country. All 138 chromosomes with typical haplotypes had one of the three most common African haplotypes. No example of the Asian or of the Cameroon haplotypes was found. The Bantu haplotype predominates in all three regions (54.8 to 73.1%), followed by the Benin haplotype (25.4 to 45.2%) and a small number of cases with the Senegal haplotype (0 to 6.9%). The mean prevalence of the Bantu haplotype of 65.9% agrees closely with historical data which indicate that 70% of the African slaves brought to Brazil originated from regions of Bantu populations.

Mitochondrial DNA (mtDNA) variation was investigated in a group of 185 unrelated individuals (64 Czechoslovaks, 99 Northern and 28 Central Italians) using total blood DNA and the six restriction enzymes HpaI, BamHI, HaeII, MspI, AvaII and HincII. Among the 25 patterns (morphs) found, two morphs for HaeII, one for MspI and one for AvaII were new and each was represented by a single individual from Northern Italy. They account for four of the five new types encountered in this survey, being the fifth type characterized by the presence of the very rare morph HaeII-13. The populations analysed confirm the Caucasoid characteristics of certain polymorphisms. A review of the European data available so far is reported.

Baseline data from Turkey is presented on phenotype and gene frequency distributions of three red cell enzyme systems (ESD, PGM1, PG1) and two blood groups (ABO, Rh). Examination of the distributions of these gene frequencies among the four geographic regions of Turkey showed that except for ESD, the Turkish population is genetically homogeneous. The gene frequencies observed in Turkey are compared with those in some countries in Europe and Asia.

The genetic polymorphism of alpha-2-HS-glycoprotein (AHSG) was studied in the population of Cabo Verde (West Africa), using isoelectric focusing in polyacrylamide gels followed by immunofixation-silver stain. AHSG frequencies are reported for the first time in a subsaharan African population. In addition to the common variants, AHSG 1 and AHSG 2, five AHSG variants were observed, including a new variant, tentatively designated AHSG 32. The allele frequencies were, AHSG*1: 0.7289, AHSG*2: 0.2111, AHSG*10: 0.0276, AHSG*3: 0.0162, AHSG*11: 0.0081, AHSG*22: 0.0065, AHSG*32:0.0016.

We have studied 506 Amerindians from three French Guiana groups: 194 Wayampi, living in Trois-Sauts, and 100 living in the Camopi area; 47 Emerillon also living in the Camopi area and 165 Wayana living on the Litani and Maroni rivers. All samples were tested for G1M (1,2,3,17), G3M (5,6,10,11,13,14,15,16,21,24,28) and KM(1) by the classical method of hemaglutination inhibition. The phenotype and haplotype distributions are presented and have been subjected to factorial analysis of correspondence. Two common GM haplotypes are GM1,17:21,28 and GM1,2,17;21,28 but with an important variation in frequency. A rare haplotype, GM1,17;21R,28, probably the result of a genetic anomaly, is frequent in the Emerillon (17%). These populations show no evidence of Negroid or Caucasian admixtures.

We analysed a sample of 55 unrelated individuals from Trino Vercellese, a village in northern Italy. It represents the only European sample which is unmixed in a comparative study of eight populations from four continents [Bowcock et al 1991a; Lin et al 1994]. RFLP analysis was performed on 32 DNA markers, for a total of 37 independent alleles. Genetic variability between populations was measured by the FST statistics (average FST is 0.138). Average heterozygosity was calculated for each marker and for each population. Genetic distances were evaluated between pairs of populations. Phylogenetic trees were reconstructed and principal component analysis performed.

We describe two new polymorphic sites identified by DdeI digestion of human mitochondrial D-Loop DNA. Their frequencies were estimated on a random group of 54 unrelated blood donors, born and descending from female ancestors of the Province of Reggio Emilia (Central Emilia, Northern Italy). These newly detected polymorphisms were generated by A to G transitions at positions 16300 and 16482 of mt-DNA. They were found at a 5% frequency in our sample whereas the remaining 95% of the sample exhibited a Cambridge sequence restriction pattern.

We studied Gc, Hp, C3 and Bf serum protein polymorphisms in the population of the Middle Sangro Valley, an area in the Abruzzo Apennine mountains on the border with the Molise region, which has maintained a highly isolated character. The gene frequency estimates obtained for the total sample of the Middle Sangro Valley were: [table: see text] The analysis of these data reveals internal heterogeneity in the population of the Middle Sangro Valley probably due to geographical and socio-cultural differences which may have give rise to local micro-evolutionary phenomena.

Data are presented on ABO, Rhesus, MNSs, P, Duffy, Kell and Kidd blood group polymorphisms in the Dzhava district, located on the southern slopes of the Main Caucasian Mountain Range. The gene frequencies, compared with those in other Osetian populations and neighbouring ethnic groups of the Caucasus, show general similarity. An exception to the general pattern is presented only by the P blood group system, where the frequencies of the alleles are significantly different form those observed in the neighbouring populations.