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J Bertranpetit

Publications and source records attributed to J Bertranpetit.

88 records · Page 5Linked to original sources
PubMed1993

Microsatellite haplotypes for cystic fibrosis: mutation frameworks and evolutionary tracers.

Highly informative intragenic microsatellite markers within the cystic fibrosis (CF) transmembrane conductance regulator (CFTR) gene allow the analysis of associations between specific mutations and haplotypes. We have analysed 440 Spanish CF families carrying 22 different CF mutations and have established haplotypes in 1,036 chromosomes for microsatellites IVS8CA, IVS17BTA and IVS17BCA. No new alleles were detected at the three CFTR microsatellites, in more than 3,000 meiosis analysed (estimated mutation rate of less than 3.3 x 10(-4)). The evolution of 16 haplotypes associated with the most common CF mutation, delta F508, and the low mutation rate at these microsatellite loci suggest that delta F508 originated within the 23-31-13 haplotype at least 53,000 years ago, very early in the history of the European population. The number of haplotype changes seen for two other common mutations, G542X (haplotype 23-33-13) and N1303K (23-31-13), suggests that they originated at least 35,000 years ago. Microsatellite allele variability associated with delta F508, G542X and N1303K demonstrates that slippage and mispairing is the main mechanism generating microsatellite alleles. In spite of the haplotype variability detected for these 3 common mutations, the association between haplotype and mutations is very strong. Mutations 1609delCA, 3667del4, delta I507 and G551D are all associated with haplotype 16-7-17, which has a frequency of 14.5% in normal chromosomes. 5 haplotypes bearing specific CF mutations were not found in normal chromosomes. Haplotype 16-46-13 is strongly associated with CF mutations E92K and 3601-111G-->C. About 23% of CF chromosomes with unknown mutations show significant linkage disequilibrium for microsatellite haplotypes.(ABSTRACT TRUNCATED AT 250 WORDS)

Base Sequence↗
PubMed1992

Complement genetic markers in schizophrenia: C3, BF and C6 polymorphisms.

Polymorphic variants of C3, BF and C6 complement factors have been investigated in schizophrenic patients subdivided according to the existence or not of a family history of both schizophrenia and other psychiatric disorders. To analyze the contingency tables, besides the usual methods, log-linear models have been fitted. Significant associations have been found in the C3 system, with a decrease of C3*F in patients (contradicting previous findings), and in the BF system, with a decrease of FS phenotype among patients (confirming some previous results). No association has been found for the C6 polymorphism (in accordance to previous results). Therefore, the present findings only partially confirm previous results and do not clarify the relationship between complement genetic markers and schizophrenia, stressing some statistical difficulties.

Alleles↗
PubMed1991

A genetic reconstruction of the history of the population of the Iberian Peninsula.

The genetic patterns detectable in human populations of the Iberian Peninsula are shown by means of 'synthetic genetic maps', i.e. geographic maps of the highest principal components (PC) of gene frequencies. This method of analysis separates independent patterns of the genetic landscape, which hopefully represents different, major evolutionary events of the past. Among these are clines established by ancient important migrations, and local differentiations of populations due to barriers responsible for relative isolation. Only events of some magnitude from a demographic point of view, involving populations having initially definite genetic differences are detectable by the method. For this to be true, the genetic consequences of these events must not have been entirely smoothed out by later, prolonged genetic exchange between neighbours; but simulations have shown that long clines produced by major migrations can be rather stable in time. The first synthetic map, corresponding to the first PC, shows that the major difference in the Iberian Peninsula is that between people originally of Basque and non-Basque descent. The recession in time of the boundaries of the Basque-speaking area seems correlated with the progressive genetic dilution of the Basque genotype in modern populations, as we move away from the centre of the Basque area. Clearly there must have been a close relationship in the progressive loss of the Basque language and increasing genetic admixture with neighbours. Most probably, Basques represent descendants of Paleolithic and/or Mesolithic populations and non-Basques later arrivals, beginning with the Neolithic. The second synthetic map is correlated with early Neolithic infiltrations from the eastern edge of the Pyrenees. It has been shown by archaeologists that, in some areas, early Neolithics lived side by side at overlapping dates with well developed Mesolithics. The demographic impact of Neolithic farmers versus Mesolithics, and therefore their genetic influence was thus less important in the Iberian Peninsula than in Central Europe. The third synthetic map shows a correlation with the linguistic and historical duality between the Atlantic and Mediterranean fringes, which developed in the first millennium B.C. and was probably determined, to some extent, by infiltrations through the Pyrenees of the Urnfield cultural elements as well as by several other later events.

Biological Evolution↗
PubMed1990

Genetic markers in schizophrenia: ACP1, ESD, TF and GC polymorphisms.

Genetic variants of red-cell acid phosphatase (ACP1), esterase D (ESD), transferrin (TF) and the group-specific component (GC) were investigated in schizophrenic patients with and without a family history of both schizophrenia and other psychiatric disorders. No evident association was found with respect to ACP1, TF and GC systems. A significant difference in the frequency of ESD heterozygotes was found between patients with and without a family history of schizophrenia.

Acid Phosphatase↗
PubMed1990

Quantitative dermatoglyphics in schizophrenia: study of family history subgroups.

Finger and a-b palmar ridge-count dermatoglyphic features were studied in schizophrenics with and without a positive family history of schizophrenia. Associations are reported for low quantitative dermatoglyphic values in schizophrenia. The differences found between the two subgroups of patients support the genetic heterogeneity of schizophrenia and stress the existence of congenital factors when there is no family history, that is, a genetic background.

Dermatoglyphics↗
PubMed1989

Variation in G + C-content and codon choice: differences among synonymous codon groups in vertebrate genes.

The relationship between G + C-content and codon usage in genes of human, mus, rat, bovine and chicken nuclear genomes was investigated. Correlation and lineal regression analyses were carried out on plots that related the frequency of each codon within each synonymous codon group to the G + C-content of the coding sequence as a whole. Under GC pressure, in most of the quartet codon groups there is a preferential choice of the C-ending codon, except in leucine and valine codon groups where the choice of the G-ending codon is preferred. Among ducts, the choice of codons specifying phenylalanine and glutamate shows the strongest dependence on G + C-content. The relationship found between G + C-content and codon usage in these genomes correlate with taxonomic distance.

Animals↗
PubMed1989

Seasonality of birth in schizophrenia. An insufficient stratification of control population?

The seasonality of birth in 142 schizophrenics from Barcelona (Spain) has been studied, showing a pattern similar to that described by other authors, with a maximum in winter. If sample is compared with the local general population there are significant differences, but these disappear when the comparison is made with a control population properly stratified by age, sex, place of birth, place of residence and social status. The same results are obtained using statistical methods suggested by other authors. The seasonality pattern usually obtained in schizophrenia could be due to a selective stratification of the ill population based on variables that might or might not be related to illness.

Adolescent↗
PubMed1988

Demographic parameters and twinning: a study in Catalonia, Spain.

Twinning rates for the years 1975-79 in Catalonia (Spain) are presented. Crude rates are very low: 7.62 per 1,000 maternities, the DZTR and the MZTR being 3.74 and 3.88 respectively. Standardized rates remain very low. Sex ratio among twin couples is also very low (0.49 male vs 0.51 female births). A multiple linear stepwise regression on the twinning rates shows MZ rates to be influenced by birth order and father's age, and the DZ rates by mother's age and birth order.

Adult↗
PubMedDate not supplied

mtDNA analysis of the Galician population: a genetic edge of European variation.

Analysis of mitochondrial DNA (mtDNA) variation has become a useful tool for human population studies. We analysed the first hypervariable region of mitochondrial DNA control region (position 16024-16383) in 92 unrelated individuals from Galicia (Spain), a relatively isolated European population at the westernmost continental edge. Fifty different sequences defined by 56 variable positions were found. The frequency of the reference sequence reaches in Galicians its maximum value in Europe. Moreover, several genetic indexes confirm the low variability of our sample in comparison to data from 11 European and Middle Eastern populations. A parsimony tree of the sequences reveals a high simplicity of the tree, with few and small well defined clusters. These results place Galicians on the genetic edge of the European variation, bringing together all the traits of a cul-de-sac population with a striking similarity to the Basque population. The present results are fully compatible with a population expansion model in Europe during the Upper Paleolithic age. The genetic evidence revealed by the analysis of mtDNA shows the Galician population at the edge of a demographic expansion towards Europe from the Middle East.

Base Sequence↗
PubMedDate not supplied

Human mitochondrial DNA sequence variation in the Moroccan population of the Souss area.

BACKGROUND: Various populations have contributed to the present-day gene pool of Morocco, including the autochthonous Berber population, Phoenicians, Sephardic Jews, Bedouin Arabs and sub-Saharan Africans. OBJECTIVE: The primary objective of the study was to complete a genetic description of the Berber-speaking population in the Souss region of southern Morocco, based on mitochondrial DNA (mtDNA) sequence analysis. SUBJECTS AND METHODS: The first hypervariable segment of the mtDNA control region was sequenced in a sample of 50 individuals from the Souss Valley, and the results compared with the extensive body of data available on mtDNA sequence variation in Europe and sub-Saharan Africa. RESULTS: Thirty-four different sequences were found: an estimated 68% of the sequences occurred throughout Europe, West Asia and North Africa, 26% originated in sub-Saharan Africa, and 6% belonged to the North African specific haplogroup U6. The Souss Valley mtDNA sequences indicated the presence of two populations which expanded at different times: the West Eurasian sequences in the Souss sample had a smaller average number of pairwise differences than pairs of sub-Saharan sequences. CONCLUSION: Detailed knowledge of the possible geographic origin of each sequence facilitated an interpretation of both internal diversity parameters and between-population relationships. The sub-Saharan admixture in the Souss Valley matched the south-north cline of sub-Saharan influence in North Africa, also evident in the genetic distances of North African populations to Europeans and sub-Saharan Africans.

Africa South of the Sahara↗
PubMedDate not supplied

Cerdanya: mountain valley, genetic highway.

In this paper the records of 7844 marriages in the parishes of French and Spanish sectors of the Cerdanya Valley have been analysed. The Cerdanya is an eastern Pyrenean valley, today divided by the Franco-Spanish border, but once united within Catalonia. The results have been reported on the one hand on a small scale using local place names, and on the other hand on a wider scale across France and Spain, because interest lies both in the geographic range from which some marital partners have come and in the relative proportions of brides and grooms from the French and Spanish parts of Cerdanya and from adjacent districts. Both mountains and the Franco-Spanish border are shown to have reduced the likelihood of marriage. Inaccessible mountain barriers appear to have been a greater obstacle to marital movement than the border. Adjacent districts and local provinces have provided a greater proportion of brides and grooms than more distant ones, but thereafter frequencies from the further regions do not decrease with greater distance. More marital partners have moved from Spain to France than vice-versa, and mobility of grooms exceeded mobility of brides. Results are relevant to genetics and the current European interest in nationality and ethnicity.

Emigration and Immigration↗
PubMedDate not supplied

Population history of Corsica: a linguistic and genetic analysis.

Genetic and linguistic differentiations within Corsica were analysed and compared; the genetic relationships of Corsica to other Mediterranean populations were also studied. Lexical distances between 49 Corsican localities were computed from a standard word list; trees built from these distances were compared with average linkage and neighbour-joining trees of genetic distances. Our lexical distance results confirmed the north/south dialectal subdivision of Corsican speeches described by linguists. No clear results were achieved with genetic distances because of the low number of loci for which data were available. Nevertheless, a tight northern cluster clearly emerged. When compared to other Mediterranean populations, Corsica showed a certain degree of differentiation, although not so marked as that of Sardinia. Corsica presented genetic affinities with Campania, Sicily, Liguria, Provence and Latium, while distances with Tuscany and Sardinia were larger. These results can be interpreted as a reflection of the prehistoric isolation of Corsica and the relative contribution to the island gene pool of prehistoric and historic invaders and immigrants from several populations.

Blood Group Antigens↗
PubMedDate not supplied

Haptoglobin phenotypes and gene frequencies in bipolar disorder: an association study in family-history subgroups.

Several studies have shown that major depression is accompanied by significantly increased plasma levels of positive acute-phase proteins such as haptoglobin (Hp). A significant higher frequency of the HP*1 allele has recently been detected in patients with unipolar major depression. Pursuing the hypothesis that certain unipolar and bipolar disorders may be genetically related, this study analyzed Hp genotype and allele frequencies in bipolar patients, taking into account their family history of major affective disorders. An increase of HP*1 allele frequency was found in the subgroup of patients with family history of exclusively unipolar disorder (70% in patients vs. 38% in controls, chi2 = 8.34, p = 0.004). The relative risk for the HP*1 carriers in this subgroup was 3.8 (chi2 = 7.29, p = 0.007). These results suggest a genetic and etiological heterogeneity in the bipolar disorder.

Alleles↗
PubMedDate not supplied

Allele frequencies for 20 microsatellites in a worldwide population survey.

20 microsatellite polymorphisms: HUMHPRT, HUMD3S1358, HUMTH01, HUMACPP, HUMVWF, HUMD16S310, HUMD4S243, HUMTPO, HUMFES/FPS, HUMF13A1, HUMDHFRP2, HUMD11S2010, HUMD13S767, HUMD9S926, HUMD2S1328, HUMD14S306, HUMD18S848, HUMD5S818, HUMD7S820 and HUMFGA were analyzed in a worldwide survey covering five continents and allele frequencies are given. There is a high heterogeneity in allele frequencies among continents. A neighbor-joining tree based on Fst distance shows a pattern of differentiation that may reflect the role of drift in the development of genetic differences among humans. The variation found between continents confirms the usefulness of tetranucleotide microsatellites in human genetic variation studies.

Alleles↗