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Biomedical subjects

E Bois

Publications and source records attributed to E Bois.

At least 37 records · Page 2Linked to original sources

Studies on an isolated West Indies population: I. Analysis of HLA genotypes.

The transmission of HLA genes was studied in an isolated population of French origin on the lesser Antilles islands in the West Indies. The study of 74 unrelated individuals, 44 of whom were genotyped, was carried out for the alleles of HLA loci: A, B, C and Bf (proactivator factor of properdin). As a result of the founder effect and the inbreeding process, the HLA haplotypes were noted to be less polymorphic than in a French continental population. Two haplotypes: A2, Cw5, B12, BfS and A3, C-, B14, BfF represent 24% of the observed haplotypes, and only 2% of the reference haplotypes in France. No significant excess or deficit of homozygotes was observed at the A and B loci.

Deafness↗

[Spina-bifida and anencephaly. Geographic distribution, correlation with HLA system (author's transl)].

Geographical variation in the incidence of an Anencephaly and Spina-Bifida is well documented. The highest rates for these malformations were found in Ireland, Wales, Scotland and in Western regions of England. These rates decrease progressively towards eastern Europe. In France the highest rates were found in some regions of Brittany. The geographical correlations between the mortality rates of Spina-Bifida and incidence of Spina-Bifida and Anencephaly and the HLA antigen frequencies are studied. There is a positive correlation with A1 and B8 and a negative one with B5 and BW35. The role of the HLA system in these associations is discussed.

Anencephaly↗

Spina bifida and anencephaly. Geographic correlation with the HLA system.

The geographical correlation between the incidence of spina bifida and anencephaly and the HLA and ABO antigen frequencies are studied. There is a positive correlation between these malformations and A1 and B8, and a negative correlation with B5 and Bw35. The role of the HLA system itself, or of a human T-like locus, is discussed. This study provides evidence of a possible genetic background of susceptibility to these malformations.

ABO Blood-Group System↗

[Incidence of cystic fibrosis in Brittany (author's transl)].

Incidence of cystic fibrosis has been estimated in three adjacent geographic areas of Brittany: North Finistere, South Finistere and Morbihan. This incidence is respectively 6.0 x 10(-4), 4.8 x 10(-4), 2.9 x 10(-4) in these three areas. A significant difference between North Finistere and Morbihan was found. Without proofs in favor of natural selection, genetic drift seems to be a possible explanation of this variation. Moreover, as in other studies, a genetic heterogeneity of the disease was not shown.

Cystic Fibrosis↗

A genetic study of two French Guiana Amerindian populations. II. Rare electrophoretic variants.

Two Amerindian populations of French Guiana were investigated for plasma proteins and red-cell enzymes. In the Wayampi tribe, rare variants were identified in 4 systems. The corresponding alleles are designated AK1 3 Wayampi, PGM1 (4/10) Wayampi, PGM2 6 Wayampi, and TfD. In the Emerillon tribe, a variant allele of PGM2, designated PGM2 6 Emerillon, was identified. For three of the systems, PGM1, PGM2, Tf, similar isozymes have been described in other Amerindian populations. These findings suggest that the corresponding alleles may have the same origin.

Adenylate Kinase↗

[Rare electrophoretic variants of the proteins adenylate kinase 1, phosphoglucomutase 1 and 2, and transferrin (AK1, PGM1, PGM2, Tf) in two populations of French Guiana].

Two small populations of inner French Guiana were investigated for red cell enzymes and serum proteins. Rare variants were found in four systems (AK1, PGM1, PGM2, Tf). Similarities between some of these variants and those found in other Amerindian populations indicate that these genetic markers may be valuable in studies of Amerindians. A mutation rate has been estimated from the results.

Adenylate Kinase↗

Cluster of cystic fibrosis cases in a limited area of Brittany (France).

Cystic fibrosis in the northern sector of the French "département" of Finistère is 1:1787 live births. Within this sector a concentration of the disease was found in a small area. The minimal frequency in this area, from 1946 to 1972, was calculated as 1 per 377 live births, the gene frequency being 0.0515. Genealogic analysis, going back to the beginning of the 18th century, showed a relationship between 8 of the 10 families to which the patients belonged. The origin of the deleterious genes may be explained by a least five primary ancestral couples living in the 18th century. Random drift is the most probable explanation for the concentration of cystic fibrosis in this region.

Cystic Fibrosis↗

Histocompatibility antigens in two American Indian tribes of French Guiana.

Two South American Indian populations were typed for HLA antigens. In each, the individuals typed were related and their genealogies were known. Determination of their genotypes was done; there seemed to be neither excess nor deficiency in homozygotes. The antigens observed, A2, A9, Aw19.2 (Aw30-Aw31), A28 for the first locus and B5, Bw15, Bw35, Bw40 for the second locus are in accordance with those previously described for other South American Indians. The two populations belong to the same primary linguistic family Tupi-Guarani and they live in the same geographic area, but there was no intertribal marriage until recently. Genetic drift can explain the differences observed.

French Guiana↗

Inbreeding in recessive diseases.

The consanguinity of parents (born in France) of individuals who have a recessive disease has been studied. The frequency of first cousin marriages is less than 0.2% in the general French population. Among the parents of affected individuals the following frequencies of first cousin matings were observed: cystic fibrosis: 1.4% cystinosis: 7.1% nephronophtisis: 5.6% spinal muscular atrophy: 4.5% albinism: 5.0% achromatopsia: 12.5% (Albinism and spinal muscular atrophy are heterogeneous conditions). The increase in the frequency of first cousin marriage relative to that of the general population is much greater, as expected, in cystinosis, which is a rare disease, than in cystic fibrosis, which is the most frequent recessive disorder in France. Inbreeding in cystinosis and cystic fibrosis was also studied by computing the distance between parental birth places. This distance is smaller in cystinosis than in cystic fibrosis.

Albinism↗

Infantile cystinosis in France: genetics, incidence, geographic distribution.

A national distribution of 66 French patients, from 49 sibships, has been studied. Segregation analysis, using the maximum likelihood method, was found to agree with the theoretical values expected in recessive autosomal inheritance. The birthplaces of these patients show an unequal geographic distribution of cystinosis, the incidence being higher in Western France. Compared with the total number of live births during the period 1959 to 1972, the minimum incidence of the condition in the province of Brittany is 1 per 25 909, and the gene frequency 0.0062. In the rest of France, the minimum incidence is 1 per 326,440 and the gene frequency 0.0018. Application of Dahlberg's formula gives a similar result. The mean inbreeding coefficient is 530 X 10(-5), a figure 23 times higher than the mean coefficient of France. An indirect test of inbreeding, the distance between parental birthplaces, was studied, first using the French administrative boundaries, second by using kilometers. This distance was constantly smaller for the parents of patients than for the parents of controls. Analysis of two erythrocyte polymorphisms (ABO and Rh) showed a large excess of group A patients when compared with overall French data. These findings are difficult to interpret on genetic grounds. The genetic reasons for the unequal geographic distribution of cystinosis in France are discussed.

ABO Blood-Group System↗

Congenital urinary tract malformations: epidemiologic and genetic aspects.

436 index patients with major congenital urinary tract malformations, 385 with upper and 51 with lower urinary tract anomalies, were studied. A significant male sex predominance was noted in each group. No apparent correlation was found between parental age, birth order, birth weight and incidence of these malformations. The association with abnormalities outside the urinary tract was more frequent in the upper urinary tract group. In this group, the mean consanguinity index was 283-10(-5) and, among those patients where a family study was made, 16.6% had positive family histories. The incidence of urinary tract malformations was 4.0% for the first degree relatives, and 1.1% for second degree relatives (grandparents only). In this group, the concordance rate was 50% in four monozygotic, and 0% (nil) in three dizygotic, twin pairs. The findings, in agreement with studies of other congenital malformations, suggest at least in part, a multifactorial etiology, particularly in the case of upper urinary tract malformations, depending upon genetic predisposition and environmental factors.

Abnormalities, Multiple↗

Gm and Inv allotypes in French Guiana Indians.

Data from 302 individuals belonging to three populations of French Guiana Indians are reported. All the phenotypes except two can be explained by three haplotypes: Gm1,21, Gm1,2,21 and Gm1,10,11,25. The gene frequencies found in the present study are generally in accordance with those previously described among other South American Indians. For the Inv1,2 gene a high value has been found for the Wayanas and the Oyampis, but a difference appears for the Emerillons who possess a low frequency.

Blood Group Antigens↗