Biomedical subjects
Publications and source records attributed to O Rickards.
Seven erythrocyte polymorphisms, namely AcP, PGM1, PGM2, EsD, GLO I, G-6-PD and Hb, have been typed in 556 unrelated adult male subjects from Bari (South Italy) and its district. The gene frequencies obtained in this sample are compared with the hitherto reported corresponding data from other Italian population samples. The results are critically discussed.
Phenotype and allele frequencies for hemoglobin types (Hb beta), acid phosphatase (AcP), phosphoglucomutase (PGM1 and PGM2), esterase D (EsD), 6-phosphogluconate dehydrogenase (6-PGD), glyoxalase I (GLO), superoxide dismutase (SOD A), and adenylate kinase (AK) as well as for haptoglobins (Hp), group-specific component (Gc), transferrin (Tf), Gm, and Inv groups and albumin, are reported in the Mbugu, Sango, Yakpa, and Baya Mandja ethnic groups in the Basse Kotto district of the Central African Republic. The total sample size amounts to 133 males and 128 females aged from 16 to 60, unrelated and healthy. A new albumin variant (albumin Mbugu) is described and discussed. The average heterozygosity is high in each group because of a high degree of exogamy. the FST average standardized value among the four groups indicates that the genetic differentiation in Basse Kotto is at level of about 2%. This indicates that the four examined groups might be considered genetically homogeneous, in spite of their different ethnic origins. The genetic distances among the four groups show that only the Baya Mandja are less closely related to the other three groups because of their foreign origin.
A rare phenotype at the phosphoglucomutase locus 1 with an electrophoretic mobility similar to that of PGM1 8-1 was found in an Italian family. The study of this variant was performed by isoelectric focusing on polyacrylamide gel. Also the isoelectric point of the PGM81 gene product was determined.
In this paper phenotype and gene frequencies of ten genetic markers (AK, AP, EsD, 6-PGD, PGM1, PGM2, Hb, Alb, Cp and Hp) of the four Albanian communities (Campomarino, Montecilfone, Portocannone and Ururi) living in Molise are reported. The gene frequencies show a high variability. The heterogeneity analysis among these villages could demonstrate significant differences between Campomarino and Montecilfone and between Campomarino and Ururi. It is interesting to note that the demographic analysis has shown the highest rate of immigration and the lowest percentages of endogamy, Albanian surnames and Albanian-speaking individuals in Campomarino. Against that Montecilfone and Ururi are showing opposite values for the same parameters. The genetic data are also indicating some differences between these Albanian communities and the Italian population. A comparison with the present population of Albany is not possible because of the lack of data.
Phenotype and gene frequencies of four blood group polymorphisms (ABO, MNSs, Rhesus, and Duffy) as well as hemoglobin types of four populations of the Republic of Central Africa are reported. All these polymorphisms are in Hardy-Weinberg equilibrium. Regarding the four blood group polymorphisms mentioned above the genetic distances according to NEI have been computed for fifteen populations of the Central-Eastern and Central-Western areas of Africa, including the four own samples. The results of these analyses are discussed.
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Informations on the genetic constitution (AcP, EsD, PGM1, AK, 6-PGD, Hb, Hp, Cp and Gc blood systems) of the Tofinu, a lacustrine population living in the pile-work of the Guinean coast (Southern Benin), are reported. The Tofinu gene frequencies are much as would be expected from the geographical position of this country. The AcP, Hp and Hb beta gene frequencies are compared with those of the other ethnic groups of Southern Benin as the Goun, Fon, Djedje, and Nago, using the contingency chi-square test of homogeneity. On the average, the five groups do not show any significant differences. Thus it results that there seems to be a common genetic origin and that the cultural-linguistic differentiation followed the evolutive biological process for the populations of this country.
BACKGROUND: The present composition of the Ethiopian population is the result of a complex and extensive intermixing of different peoples of North African, Near and Middle Eastern, and south-Saharan origin. The two main groups inhabiting the country are the Amhara, descended from Arabian conquerors, and the Oromo, the most important group among the Cushitic people. With the exception of some surveys on the general Ethiopian populations, little is known about the degree of genetic differentiation between the Amhara and the Oromo. AIM: The study seeks to investigate the genetic structure of these two heterogeneous Ethiopian populations and to characterize their relationships with other African and Mediterranean peoples. SUBJECTS AND METHODS: Amhara and Oromo individuals (n = 171) were analysed for three RFLPs (restriction fragment length polymorphisms) of the COL1A2 gene. To better define the genetic relationship between the two Ethiopian groups, and also between African and non-African peoples, genetic distances among Amhara, Oromo and other populations were estimated using the COL1A2 allele and haplotype frequencies, and the allele frequencies of 16 additional classical markers. RESULTS: chi(2) analysis applied to the COL1A2 allele and haplotype frequencies showed a small but statistically significant degree of heterogeneity between the two Ethiopian populations. Combining the information obtained from the three RFLP markers, a significant level of differentiation (Fst = 0.0147, p = 0.036) was also detected between Amhara and Oromo. The genetic distance analysis showed the separation between African and non-African populations, with the Amhara and Oromo located in an intermediate position. This pattern is consistent with the location of the two Ethiopian groups in other genetic analysis and with cultural data. CONCLUSIONS: The present findings suggest the presence of a differential level of genetic relatedness with south-Saharan peoples in the two Ethiopian groups, which could reflect their different history and seems to indicate the existence of genetic sub-structure within the country.
BACKGROUND: EcoRI, MspI and RsaI restriction fragment length polymorphisms (RFLPs) of the COL1A2 (type I collagen) gene are proving to be extremely informative markers for describing human populations; therefore they hold considerable potential for anthropogenetic research. AIM: The objective of this study was to characterize at the DNA level the Colorado Indians from Ecuador, for whom only blood group frequency information is available, and to investigate their relationships with the Cayapa-another Ecuadoran Native American group belonging to the same linguistic affiliation-and other world populations. SUBJECTS AND METHODS: Colorado Indians (n = 80) were analysed for the three anthropologically informative RFLPs of the COL1A2 gene. To better define the genetic relationship between this group and other populations, principal component analysis (PCA) was performed and genetic distances were estimated. Population genetic structure was tested through analysis of molecular variance (AMOVA) by comparing haplotype frequencies. RESULTS: COL1A2 allele and haplotype frequencies showed a certain degree of heterogeneity between the two Chibchan populations of Ecuador. The AMOVA test detected a significant level of differentiation (Fst = 0.034, p = 0.0049) between Colorado and Cayapa Indians. PC and genetic distance analyses showed a clear-cut separation between African and non-African populations; within the latter, the two Native American groups were differentiated from each other. CONCLUSIONS: The present findings suggest the presence of a low level of genetic relatedness between the Colorado and the Cayapa, despite their supposed common ethnogenesis. This confirms what has been inferred from other genetic data about the high degree of heterogeneity among Native Americans, even within the same linguistic branch, thus supporting the existence of genetic sub-structure within the central and southern American populations.
This paper reports AcP frequencies in the Mbugu and Sango of Central Africa. Among 39 sub-Saharan populations, correlations between Pr allele frequencies and latitude, humidity and altitude indicate that AcP frequencies are significantly correlated with humidity, temperature and altitude. The first-order correlations (constant humidity) diminish by approximately 70% relative to the zero-order correlation.
On a sample of the population of mixed African ancestry living in Bluefields, Nicaragua, the pattern of migration and the distribution of red cell and serum genetic markers have been studied. It is concluded that, in spite of a considerable level of internal and external migration, a distinctive genetic structure is maintained by the population. Moreover, a strongly negative assortative mating can be observed between people inhabiting the western and eastern areas of Nicaragua. It is estimated that most, if not all, of the genetic pool of the population is accounted for by a process of admixture between African and Indian peoples.
The Cayapa Indians are a population of 3600 individuals living in Ecuador, along the Cayapas River and its tributaries. They are thought to have migrated from the Andes, north of Quito, and settled in the Cayapas area five centuries ago as a consequence of Inca expansion and of the Spanish conquest. In order to study the genetic structure of the Cayapa and their relationships with other native American peoples, and to enquire on the possibility of admixture from nearby Black communities, we have investigated a sample of 139 individuals for seven plasma genetic markers (F13A, F13B, ORM1, AHSG, C6, C7 and APOC2) by isoelectric focusing and immunoblotting. The following gene frequencies have been found: F13A*1 = 0.824, F13A*2 = 0.176; F13B*1 = 0.126, F13B*3 = 0.874; ORM1*1 = 0.554, ORM1*2 = 0.446; AHSG*1 = 0.275, AHSG*2 = 0.725; C6*A = 0.131, C6*B = 0.814, C6*A21 = 0.055; C7*1 = 1.000; APOC2*1 = 1.000. The findings confirm, whenever the comparison was possible, quite a good resemblance of the Cayapa with other Native American populations.
Serum samples of 864 unrelated healthy male and female individuals belonging to nine provinces of Sicily were types for Glm (1,2,3,17), G3m (5,10,11,13,14,15,16,21), and KM (1). With the exception of the Trapani sample these samples are characterized by the presence of five GM haplotypes: GM*1,17;21,26; GM*1,2,17;21,26; GM*1,3;5,10,11,13,14,26; GM*3;5,10,13,14,26; and GM*1,17;10,11,13,15,16. The interpopulation variability in the distribution of these haplotypes is considerable, which is especially due to haplotypes GM*1,3;5,10,11,13,14,26, and GM*3;5,10,13,14,26. However, no clear-cut clustering of the samples according to historical or geographical facts could be shown. Comparisons with other Italian populations reveal the considerable genetic difference of the Sicilians, which is in particular caused by the presence of the haplotypes GM*1,3;5,10,11,13,14,26, and GM*1,17;10,11,13,15,16. These haplotypes are quite uncommon in Europeans and may reflect gene flow from the Middle East. The KM phenotype and allele frequencies also show a considerable interpopulation variability among the nine Sicilian samples, but as for GM no distinction between eastern and western provinces of Sicily is present.
Esterase D (ESD), glyoxalase 1 (GLO1), phosphogluconate dehydrogenase (PGD) and phosphoglucomutase 1 and 2 (PGM1 and PGM2) systems have been studied in the Salerno province (Campania, Southern Italy). The mean weighted frequencies for the Campania region were calculated. These frequencies show a general similarity to those reported for the other Italian regions.
Haptoglobin (HP), transferrin (TF), group-specific component (GC) and alpha-1-antitrypsin (PI) polymorphisms have been studied in Sardinia and the following gene frequencies have been found: HP*1 = 0.389, TF*C1 = 0.754, TF*C2 = 0.213, TF*C3 = 0.032, GC*1F = 0.193, GC*1S = 0.546, GC*2 = 0.260, PI*M1 = 0.607, PI*M2 = 0.221, PI*M3 = 0.126, PI*S = 0.040 and PI*Z = 0.006. These findings confirm the genetic uniqueness of Sardinians compared to the other Italian populations.