Genetic structure of southwestern Corsica (France).

The distribution of nine red cell enzymes (ACP, ADA, AK, DIA, ESD, GLO1, PGM1, PGD, and SOD) and seven plasma proteins (C3, GC, HP, ORM, PI, PLG, and TF) was analyzed in a sample of 274 unrelated individuals from the southwestern area of Corsica (France), specifically from Ajaccio and nearby villages. The aim of the research was to study the genetic structure of Corsica and to add further to our knowledge about microgeographic variability of polymorphisms in Corsica. The analysis, carried out by genetic distances and R-matrix through 39 alleles of 13 genetic markers, reveals a certain degree of differentiation within Corsica. The results show a genetic heterogeneity between Corsica and other European and Mediterranean populations, although the genetic differences appear to be smaller between Corsicans and Sardinians than among Corsicans and other compiled populations. Am. J. Hum. Biol. 10:567-577, 1998. © 1998 Wiley-Liss, Inc.

HLA phenotype and haplotype frequencies in Sardinia (Italy).

The gene and haplotype frequencies of the HLA-A, B, Cw, DR and DQ loci were determined in two Sardinian samples from the Nuoro (N = 252) and Sassari (N = 153) districts. Our data were compared with those reported for other Italian, European and Mediterranean populations and previously studied Sardinian samples. The results showed that the two samples differ from other Italian and European populations in the frequencies of many alleles and haplotypes. For example in the A2, B18, Cw5 and DR3 allele frequencies and the A1-B8, A2-B17, A3-B7, A30-B18, A2-Cw7, A30-Cw5, A30-DR3, A32-DR2, Cw5-DR3 and Cw7-DR4 haplotype frequencies. In common with the Mediterranean populations, Sardinians, too, have a limited number of haplotypes with significant linkage disequilibrium. The results revealed, therefore, significant genetic differentiation between Sardinians and other European and Mediterranean populations, confirming the genetic peculiarity of the Sardinians.

Efficacy of specific bioelectrical impedance vector analysis (BIVA) for assessing body composition in the elderly.

OBJECTIVES: This study aimed to ascertain the efficacy of bioelectrical impedance vector analysis (BIVA) in assessing body composition in the elderly by comparing findings with the results of dual-energy X-ray absorptiometry (DXA), and to test an analytical variant of the method (specific BIVA). DESIGN: Cross-sectional study. PARTICIPANTS: The sample comprised 207 free-living elderly individuals (75 men and 132 women) aged 65 to 93 years. MEASUREMENTS: Anthropometric and bioelectrical measurements were taken according to standard criteria. BIVA was applied using the 'classic' procedure and correcting bioelectrical values for body geometry to obtain an estimate of the whole-body impedivity. DXA was used as a reference body composition assessment method. BIVA (classic and specific values) and DXA findings were compared using Student's t and Hotelling's T2 tests, and Pearson's correlation coefficient. RESULTS: In both sexes, BIVA distinguished between individuals with different amounts of fat and fat-free mass (lean mass including bone mineral content), according to DXA, but not between those with different proportions of fat mass (FM%). Specific bioelectrical values detected changes in body composition. CONCLUSION: BIVA should be used with caution for evaluating body composition in the elderly. Specific bioelectrical values proved effective, showing promise as a methodological variant of BIVA, suitable for identifying age-related changes in body fatness.

Nutritional and psycho-functional status in elderly patients with Alzheimer's disease.

OBJECTIVES: Analysis of variations of nutritional status in relation to psycho-functional conditions in elderly patients with mild to moderate Alzheimer's disease (AD) by means of bioelectrical impedance vector analysis (BIVA). DESIGN: Cross-sectional study. SETTING: Alzheimer Center, SS. Trinità Hospital, Cagliari (Italy). PARTICIPANTS: 83 free-living patients (29 men, 54 women) with mild-moderate Alzheimer's disease, aged 66 to 96 years, and 91 age-matched controls (37 men and 54 women). MEASUREMENTS: Nutritional status was evaluated by anthropometry (weight, height, waist and upper arm circumferences, triceps skinfold; body mass index, BMI; arm muscle area, AMA); Mini Nutritional Assessment, MNA®; bioelectrical impedance vector analysis, BIVA. Psycho-functional status was assessed by the Mini Mental State Examination (MMSE), Geriatric Depression Scale (GDS), Activities of Daily Living (ADL), and Instrumental Activities of Daily Living (IADL). RESULTS: Compared to the control groups, patients with Alzheimer's disease had a worse psycho-functional and nutritional status. BIVA detected lower body cell mass in Alzheimer's patients with respect to controls (men: T²= 23.4; women: T²=27.3; p<0.01), as well as in the female patients with lower levels of IADL and MMSE (respectively, T²= 8.0; T²=7.4; p<0.05). In patients with AD, a worse psycho-functional status was associated with obesity. CONCLUSION: The psycho-functional decline of patients with AD is related to body composition variations, with a relative increase of fat mass with respect to the muscle component. The BIVA technique distinguished patients from controls and patients with different levels of cognitive decline. Therefore, it is a suitable tool for the screening and monitoring of nutritional status in Alzheimer's disease.

Variations of somatotype in elderly Sardinians.

Somatotyping is an effective technique for the study of anthropometric variations and body composition in elderly subjects, even though it has not often been used in this field. The present study was conducted on a sample of 280 healthy Sardinians (134 men and 146 women) of age 60-89 years, subdivided into three age classes (60-69 years; 70-79 years; and 80-89 years). Somatotypes were computed according to Carter and Heath (Somatotyping-Development and Applications. Cambridge, England: Cambridge University Press; 1990). The results show a dominance of the endo- and mesomorphic components in the elderly subjects, with less development of ectomorphy than in younger individuals. In a comparison with other populations, our sample shows strong development of endomorphy and especially of mesomorphy, while ectomorphy values are generally low. Age-related variations are significant in both sexes and consist in a progressive reduction of the endomorphic component, particularly in the 80-89-year class (endomorphy in the three age classes: 6.4, 6.1, and 5.3 in men; 8.1, 7.8, and 6.8 in women). The mesomorphic component is characterized by stability (age variations: 6.4, 6.4, and 5.9 in men; 6.3, 6.4, and 6.3 in women) and the ectomorphic component by a slight increase (age variations: 0.5, 0.6, and 0.8 in men; 0.4, 0.3, and 0.5 in women). Sex differences are significant and especially large for the endomorphic component, with generally higher values in women. The sexual dimorphism tends to decrease with age. The results are discussed with regard to the biology of aging, with emphasis on the potential application of somatotype to studies of the elderly population.

Distribution of some erythrocytary enzymes in the Piaroa Indians of Venezuela.

Eight enzyme gene markers were studied in a sample of Piaroa Indians of Venezuela. ADA, DIA, PGD and AK markers seemed to be non-polymorphic whereas the following markers were found to be polymorphic: ACP1, where the only common electrophoretic alleles present were ACP1*A and ACP1*B (.955); ESD (ESD*1 = .781); PGM1 (PGM1*1 = .736) for which the subtypes (PGM1*1S = .546; PGM1*1F = .190; PGM1*2S = .140; PGM1*2F = .124) were also tested, and GLO1 (GLO1*1 = .347). Some showed a certain heterogeneity in distribution within the Piaroa population. The Piaroa Indians turned out to be different from other ethnic groups living in the same territory.

Windsurfer somatotypes.

On the basis of data gathered during a series of Pre-Olympic Trials and the World Championships, both held at Cagliari (Italy) in 1983 and 1986, respectively, the somatotypes of athletes practicing windsurfing were studied. The sample is composed of 79 male athletes: 22 Sardinians, 31 mainland Italians, and 26 Europeans. The Heath-Carter anthropometric method (1967) was used to somatotype the individuals under study. Both the total sample as well as the three subsamples are characterized by almost identical average values of the three components. A subsample of athletes was formed, who had obtained important performances in their carriers (victories in World, European and Italian championships, participation in the Olympic Games etc.). In this group of top athletes it was seen that the best results in windsurfing are obtained when there is an even development of the three components (2.57-2.68-2.97) or a slight ectomorphic predominance.

Distribution of PGM1 and GC subtypes in the four Sardinian provinces.

Genetic polymorphism subtypes of PGM1 and GC were studied in four samples of the Sardinian population from the four Provinces of the island. The results show heterogeneity within the Sardinian population. The PGM1 alleles exhibiting the greatest variability were: PGM1*1S and PGM1*1F, with a range of .675-.724 (Nuoro - Sassari) and .072-.107 (Sassari - Nuoro) respectively. The observed GC allele frequency range were: GC*1F = .029-.168 (Cagliari - Sassari); GC*1S = .565-.752 (Sassari - Oristano); GC*2 = .194-.267 (Cagliari - Sassari). Sardinians showed a marked differentiation with respect to other Italian and European populations thus confirming their genetic peculiarity.

Blood groups of the Sardinian population (Italy).

The genetic polymorphism of eight red cell blood group systems was examined in a population sample from Sardinia (Italy). The Sardinian frequencies of most of the examined genes were found out the range of Italian populations. Relationships among Italian and other Mediterranean populations were examined by principal component analysis. This kind of analysis confirms the genetic peculiarity of the Sardinian population.

Gc and C3 polymorphisms in Central Sardinia.

The distribution of phenotypes and gene frequencies of the group-specific component (Gc) and C3 complement were studied in Central Sardinian sample. The gene frequencies were:Gc1 = 0.733; C3F = 0.237.

Dental agenesis in Sardinians.

The authors report on the results of a study on the dental agenesis frequency in a sample of 420 individuals (152 males, 268 females), aged between 8 and 20 years, from Sardinia (Italy). 18.33% of the examined individuals (22 males, 55 females) show congenital absence and/or morphometric reduction of at least one tooth. The frequency of congenital absence of teeth in Sardinians lies in the middle of the range of Caucasoid populations, but the average (mean = 1.7) per individual seems to be the lowest ever reported. In some traits of agenesis Sardinians show great similarity to other isolated populations. This suggests that dental agenesis is probably affected by the same factors (e.g. isolation and inbreeding), which are responsible for the present genetic structure of the Sardinian population.

AcP and EsD polymorphisms in Central Sardinia.

A sample of the population from Central Sardinia was studied with respect to acid phosphatase (AcP) and esterase D (EsD) enzymes. The gene frequencies were: AcPA = 0.322, AcPB = 0.617, AcPC = 0.061 and EsD1 = 0.892. The results were compared with those of other Italian populations.

AK, PGM1 and 6PGD polymorphisms in Central Sardinia.

Adenylate kinase (AK), phosphoglucomutase (PGM1) and 6-phosphogluconate dehydrogenase (6PGD) polymorphisms were investigated in a sample of individuals from Central Sardinia. The gene frequencies were: AK1 = 0.973, PGM1(1) = 0.842 and PGDA = 0.969. The frequencies were compared with those of other Italian populations.

A study of several genetic markers in the Corsican population (France).

The distribution of nine genetic markers was studied in a sample of 170 individuals coming from Corte (Corsica, France). The corresponding gene frequencies were as follows: ACP*A = 0.080, ACP*B = 0.887, ACP*C = 0.033; ESD*1 = 0.854; AK*1 = 0.976; PGD*A = 0.991; DIA*1 = 0.994; GLO1*1 = 0.278; PGM1*1S = 0.694, PGM1*1F = 0.100, PGM1*2S = 0.153, PGM182F = -.053; C3*S = 0.793, C3*F = 0.183, C3*V = 0.024; GC*1S = 0.713, GC*1F = 0.079; GC*2 = 0.207. These findings were discussed in the context of other Mediterranean populations. The results showed a relatively high genetic heterogeneity of Corsicans compared to other populations. The genetic differences appeared to be smaller between Corsicans and Sardinians than among Corsicans and other Mediterraneans.

Genetic data on Alghero population (Sardinia): contrast between biological and cultural evidence.

Data on 20 genetic polymorphisms (61 alleles) in the Algehero population on the northwestern coast of Sardinia are presented and discussed in relation to its linguistic peculiarity inside the island. Since the Aragonese (Spain) conquest of Sardinia in the 13th century, the Catalan language, the same as that spoken in Northeastern Spain and certain districts of Southern France, has been used in Alghero even until today. Analysis for heterogeneity of gene frequency distributions indicates that the genetic information obtained on Alghero is adequate to discriminate Sardinians from other neighbouring populations. Genetic variation between populations measured through genetic distances and principal-component analysis shows that the present-day population of Alghero is much closer genetically to Sardinians than to Catalonians. Our genetic results do not support any interpretation of the linguistic affinities between Alghero and Catalonia at present as indicative of biological kinship.

C3 polymorphism and NADH diaphorase types in Sardinia (Italy).

C3 and DIA1 types were studied in Sardinians from four provinces. C3 showed a heterogeneous distribution in the four subsamples and C3*F gene varied between 0.235 (Province of Sassari) and 0.154 (Province of Oristano). No rare types were found in Sardinia in contrast to mainland Italy. There are significant differences compared with some Italian populations on the mainland. DIA1*2 allele varies between 0.0026 (Province of Cagliari) and 0.0157 (Province of Nuoro). Also DIA1 showed a heterogenous distribution.

Serum protein markers in the Piaroa Indians of Amazonia (Venezuela).

A sample of 121 Piaroa Indians from the Federal Amazonia Territory (Venezuela) was studied for the following serum protein polymorphisms: haptoglobin (HP), group-specific component subtypes (GC), orosomucoid (ORM), third component of complement (C3), transferrin C subtypes (TF) and alpha 1-antitrypsin subtypes (PI). The gene frequencies in the whole sample were: HP1 = 0.821; GC1S = 0.698; GC1F = 0.058; GC2 = 0.244; ORMS = 0.434; C3S = 0.699; C3F = 0.289; C3var = 0.012; TFC1 = 0.955; PIM1 = 0.467; PIM2 = 0.004; PIM3 = 0.529. The studied Piaroa sample came from three different communities: Gavilan, Paria and Alto Carinagua. The distribution of GC, C3 and HP polymorphisms was heterogeneous within the three groups. All the examined serum protein markers were polymorphic, in contrast to some enzymatic markers (ADA, DIA, 6PGD, AK) previously studied, which were shown to be monomorphic in the Piaroa. The results were compared with data from other populations living in the same territory.

Study on the variability of seven genetic serum protein markers in Corsica (France).

By this investigation we want to contribute to our knowledge on the genetic characteristics of the Corsican population. The distribution of seven genetic serum protein markers (PI, TF, GC, ORM, HP, C3, PLG) was analyzed in a sample of 291 individuals coming from the central and northern areas of Corsica, i.e. from Corte and Bastia. The two samples do not show significant differences in the distribution of the genetic markers under study. The comparisons with other Mediterranean populations confirm the results of previous investigations on genetic red cell enzyme markers (Vona et al. 1995), i.e. a relatively high genetic heterogeneity of Corsicans compared with other Mediterranean populations.

Genetics, geography, and culture: the population of S. Pietro Island (Sardinia, Italy).

An interesting aspect of the island of Sardinia (Italy) is the wide range of genetic variability within the island itself. The variability is widened by the presence of some populations of different ethnic origin who speak a language other than Sardinian. This work deals with the study of the genetic structure of the Carloforte population which inhabits the tiny island of S. Pietro 4 km off the southwest coast of Sardinia. S. Pietro was first populated in 1738 by emigrants coming from the island of Tabarka (Tunisia) who spoke an archaic form of the Ligurian dialect. Data on genetic polymorphisms in the Carloforte population are presented and discussed in relation to some Sardinian and Italian populations. Data on demographic and matrimonial structure are also presented. The genetic analyses show the Carloforte population as being clearly separated from both Sardinians and continental Italians. The isolation of Carloforte, highlighted by language diversity, endogamy, and consanguinity levels and marriage area, supports the idea of genetic diversity linked to cultural peculiarity.

Genetic analysis of Sardinia: I. data on 12 polymorphisms in 21 linguistic domains.

(1) The microgeographic structure of Sardinia, well documented from a historical and linguistic point of view, further supported by archaeological evidence, can also be dissected at the genetic level: gene frequencies show heterogeneities which are statistically significant. (2) Dendrogram analyses performed with different methods lead to the same result: even if gene frequencies cluster linguistically defined geographic domains in agreement with historical and archaeological evidence, no phylogenetic tree can be inferred, very likely because the assumptions which allow a phylogenetic tree to be a valid model of evolution (mainly constant evolutionary rates and independence between branches) do not apply to the genetic history of Sardinia. (3) Evidence of a qualitative association between distribution of genes and distribution of languages or dialects seems to emerge also at the microgeographic level of our analysis. More linguistic and genetic data are planned to be considered.