C.M. Lostao

Fluctuating dermatoglyphic asymmetry: genetic and prenatal influences

Genetic and environmental prenatal factors influencing the fluctuating asymmetry of the a-b interdigital ridge count are examined. From the results obtained we can conclude that fluctuating asymmetry of the a-b interdigital ridge count is poorly influenced by genetic factors. We suggest that fluctuating asymmetry of dermatoglyphics provides a good measure of developmental stability in humans, especially for males. The results also indicate that random environmental factors, acting before the 19th week of embryonic development, could be related to the differential timing of maturation of the sexes.

Distribution of Cepaea nemoralis according to climatic regions in Spain

121 Populations of Cepaea nemoralis were sampled in Spain. In an area which extends from the coast of the Bay of Biscay to 182 km inland, following the meridian 3° west of Greenwich, and which has a width of approximately 40 km. In this study, we analysed the relationships between the populations and some selective agents, such as predation by Turdus ericetorum and climatic factors. These latter are represented by indirect parameters, such as altitude and distance from the sea, and direct parameters such as rainfall or temperatures. Visual selection is unimportant in the sampled populations. It was observed that our area of study is subdivided into 3 zones: Zone 1. Transitional and Zone 2, which have very different phenotype frequencies. What is more, these Zones correspond to very different climatic regions. Zone 1 is located in the climatic region known as “Green Iberia”. The most frequent phenotypes of Cepaea nemoralis are the pale ones. Zone 2 is located in “Brown Iberia”, and the most frequent phenotypes are the dark ones. Therefore we believe that in the populations sampled, one or more climatic factors are operating, and presumably causing the subdivision of these populations into Zones 1 and 2.

The FMR1 CGG repeat and linked microsatellite markers in two Basque valleys

Fragile X syndrome is associated with an unstable CGG repeat sequence in the 5′ untranslated region of the first exon of the FMR1 gene. The present study involved the evaluation of factors implicated in CGG repeat stability in a normal sample from two Basque valleys (Markina and Arratia), to discover whether the Basque population shows allelic diversity and to identify factors involved, by using the data in conjunction with previous findings. The study was based on a sample of 204 and 58 X chromosomes from the Markina and Arratia valleys, respectively. The CGG repeat, the AGG interspersion and two flanking microsatellite markers, FRAXAC1 and DXS548, were examined. In the Markina valley, gray zone alleles (⩾35 CGG repeats) were associated with anchoring AGGs, with the longest 3′ pure CGG repeats of the valley (=15), with the 5′ instability structure 9+n and with one principal fragile X FRAXAC1–DXS548 haplotype 42–50. In the Arratia valley, gray zone alleles (⩾35 CGG repeats) showed the highest frequency among the Basque samples analyzed, and were associated with anchoring AGGs, with the longest 3′ pure repeats (⩾20), with the 5′ instability structure 9+n and with one ‘normal’ FRAXAC1–DXS548 haplotype 38–40 (these data from Arratia suggest the existence of a ‘protective’ haplotype). The results showed, on the one hand, differences between Markina and Arratia in factors implicated in CGG repeat instability and, on the other hand, a great similarity between the general Basque sample from Biscay and the Markina valley.

Dermatoglyphic variation in Spanish Basque populations

The present study involves the evaluation of digital dermatoglyphic traits of 2185 unrelated individuals (1152 females and 1033 males) from 17 natural valleys of the four Basque provinces (Vizcaya, Guipúzcoa, Navarra, and Alava) in the Spanish Basque Country. Univariate intervalley and between-sex comparisons were carried out by means of chi-square contingency analysis for pattern types and by means of one-way analysis of variance for ridge counts. Multivariate intervalley comparison was carried out by means of correspondence analysis for pattern types and by principal component analysis for ridge counts. The results of this study are notable for the following findings: (1) in general, all variables are significantly heterogeneous among valley populations; (2) there was a greater differentiation among the valley populations than between sexes in one valley population; (3) affinities among the intervalley populations depend on the variables considered; (4) the valley populations from Vizcaya resemble those from the Pyrenees; (5) based on interprovince comparisons, the Vizcaya and Navarra samples are the closest; (6) in general, the valley samples from Alava are the worst clustered; (7) the universality of dermatoglyphic component structure fits better in males.

Acid Phosphatase, Adenosine Deaminase and Esterase D Polymorphisms in the Spanish Basque Population

The 3 red-cell polymorphic systems acid phosphatase (ACP), adenosine deaminase (ADA) and esterase D (ESD) have been studied in a random sample of 1,112 individuals from the Basque country: The allelic frequencies obtained were ACP*A = 0.275, ACP*B = 0.718 and ACP*C = 0.007; ADA*2 = 0.021, and, ESD*2 = 0.066. The allelic frequencies have been compared with those of other Basque and other European populations. In comparison with Basques, significant differences were detected only for ACP, whereas as regards other Europeans significant differences were obtained with practically all the populations compared for the 3 genetic systems studied. The low values of the less frequent alleles, especially that for the ACP*C allele which is the lowest reported in Europe, are noteworthy.

Chromosomal Fragility in a Behavioral Disorder

Numerous studies have shown there is consistent evidence implicating genetic factors in the etiology of autism. In some cases chromosomal abnormalities have been identified. One type of these abnormalities is gaps and breaks nonrandomly located in chromosomes, denominated fragile sites (FS). We cytogenetically analyzed a group of autistic individuals and a normal population, and we examined the FS found in both samples with the aim of (1) comparing their FS expression, (2) ascertaining whether any FS could be associated with our autistic sample, and (3) examining if there are differences between individual and pooled-data analyses. Different statistical methods were used to analyse the FS of pooled and individual data. Our results show that there are statistically significant differences in the spontaneous expression of breakages between patients and controls, with a minimal sex difference. Using the method for pooled data, eight autosomal FS have preferential expression in patients and five patients were found to be positive at FS Xq27.3. With the method per-individual analysis, four FS emerged as specific in our autistic sample. Inferences of FS from pooled data were different from those of individual data. The findings suggest that although analysis of pooled data is necessitated by the problem of sparse data, analysis of single individuals is essential to know the significance of FS in autism.

A cline in the acid phosphatase1 distribution in the Iberian Peninsula

Blood samples from autochthonous and unrelated persons were examined for acid phosphatase (ACP1) phenotypes. The subjects were 143 Spanish Basques, 118 people from León and 295 from Castile. The samples were typed using starch gels, with one surface coloured with phenolphthalein diphosphate (Na5 salt) and the other surface revealed with 4-methylumbelliferyl-dihydrogenphosphate. The gene frequencies observed are compared with those obtained by other authors.

Characterization of digital dermatoglyphic features in Salazar Valley: comparison with other Basque valleys

Digital dermatoglyphics of a sample from the Basque Valley of Salazar, situated in the West of the Pyrenees, were analysed. The results showed bimanual differences in both sexes, and also sexual differences for both hands. The comparative study with other Basque valleys showed that, in spite of their supposed common origin, the geographic barriers and the isolation have generated a genetic/dermatoglyphic and linguistic differentiation.

Twin study of digital dermatoglyphic traits: Investigation of heritability

Digital patterns of a sample of monozygotic and dizygotic twins were analyzed to obtain heritability values for the four basic types of patterns: arch, tented arch, loops, and whorls. Loops have been separated according to their orientation radial or ulnar. To carry out this study, we used the Holzinger and Clark indices. The results show highest concordances for monozygotic twins except for ulnar loops of the left hand and radial ones of the right hand. Different values of heritability were found for the right and left hands, with finger I having the highest values.

Some red cell enzymes and haptoglobin gene frequencies in two Basque regions and León

A study was conducted to determine the distribution of phenotypes and gene frequencies of haptoglobin, phosphoglucomutase 1, esterase D, 6-phosphogluconate dehydrogenase and three monomorphic systems SOD, sMDH and NADH DIA I. Results obtained from two Basque regions and León were compared with those from other Spanish populations. Gene frequencies observed in the León sample were similar to those obtained from the other Spanish samples. The Basque samples differed from the other Spanish populations in the gene frequencies of esterase D.