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

Amp-FLPs are simple and rapid tools for genetic characterization of both individuals and populations. This paper presents allele frequencies of four Amp-FLPs (ApoBII, MCT118, YNZ22, and COL2A1) based on the analysis of more than 100 unrelated Caucasoid Slovaks. The proportion of heterozygotes observed and expected, and the probability that two individuals taken at random from the population would be identical in a given polymorphism (PI), was determined for each Amp-FLP.

A sample of 140 Chuetas (descendants of Majorcan Jews) were typed for the GC, A2HS, ORM, ITI and HP serum proteins. Studies on ORM and ITI markers have not yet been reported in other Jewish populations. The allele frequencies obtained were: GC*1 = 0.610; A2HS*1 = 0.787; ORM*F1 = 0.339; ORM*S = 0.497; ITI*1 = 0.581; ITI*2 = 0.414; HP*2FS = 0.625; HP*1S = 0.230; HP*1F = 0.135. Some rare variants were found in polymorphic frequencies (ORM*S1 = 0.043; ORMS*S2 = 0.096; A2HS*10 = 0.015). These results have been compared with those found in other Jewish and non-Jewish European populations. The relatively high frequency of the HP*2FS allele and the presence of ORM*S1 and ORM*S2 variants in Chuetas show the Jewish origin of this population. The frequencies of GC and A2HS in Chuetas are similar to those found in other surrounding non-Jewish populations. ITI results are similar to those found in the two European populations studied. HP frequencies suggest a Spanish admixture.

The data presented here are on population structure and genetic markers (ABO, RH, MN, HP) in two series of so-called Slovak Romany subethnic groups from a single region (Gemer) in the Southeastern part of Slovakia. The results demonstrate that favourable conditions have existed for population genetic mechanisms operating in isolated populations, namely genetic drift and inbreeding. In addition, an attempt was made to compare the observed data with those available for other Romany populations and for Slovaks.

A random sample of 503 individuals from five endogamous groups of Sri Lanka was studied for the genetic polymorphism of the group specific component (GC) and transferrin (TF) using isoelectric focusing. Both systems showed statistically significant heterogeneity among the five main populations of the island. The GC allele frequencies of Malays are significantly different from those of the other four populations (Sinhalese, Tamils, Moors and Burghers). However, the TF system shows less variation, since only the Moors show a significant heterogeneity compared to Tamils and Burghers. The frequencies found in the present study are very different from those reported for the populations of the Indian mainland.

The distribution of the alpha 1-antitrypsin (Pi) phenotypes and subtypes was investigated in a population sample of 1060 unrelated individuals from Serbia (Yugoslavia). The allele frequencies estimates were: Pi*M1: 0.702; Pi*M2: 0.183; Pi*M3: 0.088; Pi*Z: 0.013, Pi*S: 0.007; Pi*P: 0.004; Pi*F: 0.003. The observed phenotype frequencies differed very significantly from those expected assuming H.W. equilibrium (chi 2 = 49.51, p < 0.0005). The deviation from equilibrium involved the three Pi*M subtypes: an excess of Pi*M1, Pi*M2 and Pi*M3 homozygotes was found, with the corresponding decreased number of M1M2 and M1M3 heterozygotes. The possible significance of this finding is discussed.

Rhesus phenotypes are presented for a total of 2,052 individuals belonging to three sympatric populations of New Caledonia: Kanaks (Melanesians), Wallisians (Polynesians) and Europeans born in New Caledonia. The maximum-likelihood gene frequency estimations reveal a significant deviation from Hardy-Weinberg equilibrium for the Kanak and Wallisian samples. As suggested on statistical grounds, this disequilibrium can be attributed to antigene mistypings, frequently encountered for this system. This hypothesis leads to new estimations of Rhesus haplotype frequencies for the two samples. They reveal a high degree of genetic similarity (89.6%) between Kanaks and Wallisians, with little or no evidence of admixture with Europeans from New Caledonia. The latter are genetically close to southern Europeans in having a very high R1 frequency.

Rhesus haplotype frequencies computed for 804 and 546 Wallisians from New Caledonia are compared to the data collected for 13 Oceanian samples belonging to the same Austronesian linguistic family. Genetic distances are computed between the 15 populations and used for a principal coordinate analysis. Kanaks are genetically close to Fidjians, while the Wallisian sample share a high genetic similarity with the Tonga islanders. The results obtained for the whole area including the Wallis homeland for the Wallisian sample indicate a tight relationship between geographical and genetic differentiations in the Pacific, supported by a high correlation coefficient between the two distance matrices. However, the observed patterns are better explained by the history of migrations reconstructed from archaeological and linguistic data than by a pure isolation-by-distance model.

The population of East Slovakia was studied for the following red cell isoenzymes: acid phosphatase (ACP), phosphoglucomutase (PGM), adenosine deaminase (ADA) and esterase D (ESD). The gene frequencies observed were as follows: ACP1*A = 0.3330, ACP1*B = 0.6143, ACP1*C = 0.0527, PGM1*2 = 0.2673, ADA*2 = 0.0721, ESD*2 = 0.1061. No significant differences were found between East Slovakia gene frequencies in this study and those of Herzog [1992] on inhabitants of Prague and those of Bambúchová [1985] on the Bratislava population.

The genetic polymorphism of the human Properdin Factor B (BF) in five populations of the Iberian Peninsula (Galicia, Castilla-Leon, Castilla-La Mancha, Extremadura and Western Andalusia) was analysed by means of Isoelectric Focusing in polyacrylamide gels followed by Immunofixation-Silver Staining. Statistical analysis of heterogeneity showed significant differences in the distribution of BF allele frequencies among the Iberian populations so far examined. The high allele frequencies obtained for BF*F and BF*F1 give support to the allelocline distribution hypothesis in the European continent (regression analysis between allele frequency and latitude: r = -0.6237 and r+ -0.8058, for BF*F1 and BF*F respectively).

The results of a collaborative study involving about one third of the total DMD and BMD cases living in the Italian territory are reported. The analysis of the breakpoint frequency by intron revealed significant differences among regional groups of DMD patients (for introns 2, 11 and 50 in Sardinia and for introns 9 and 45 in northeastern Italy), whereas no regional differences were observed among regional groups of BMD patients. These differences involve the same Italian regions which previous studies, performed by different markers, identified as "genetically differentiated". The data support the possibility of a differential distribution among populations of some intronic sequences, facilitating the origin of deletion breakpoints within the dystrophin gene.