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L Hallé

Publications and source records attributed to L Hallé.

12 recordsLinked to original sources
PubMed1998

HLA-DR gene frequencies in a Zaïrean population with particular reference to rheumatic diseases.

Epidemiological studies have shown that rheumatic diseases such as rheumatoid arthritis and systemic lupus erythematosus are uncommon in black Africans, and in this population the prevalence and the clinical features of these rheumatic diseases are variable. Environmental and genetic factors have been pointed out to explain this variability. In the present study, HLA-DR genes have been determined in a Zaïrean population in order to compare our results with those found elsewhere in other black populations of the same Bantu origin. Our results show that the frequency of HLA-DR1 is higher than in Nigerians, Zimbabweans and Xhosas, the decrease in Xhosas being statistically significant (p < 0.006). The HLA-DR3 frequency is higher in Zaïreans than in Nigerians but not significantly, while it is lower than in Xhosas (p < 0.003) and in Zimbabweans (not significant). The HLA-DR4 frequency is higher in Zaïreans than in Nigerians but it is lower than in Xhosas and Zimbabweans; the differences are not statistically significant. The HLA-DR8 frequency is lower in Zaïreans than in Nigerians while it is higher than in Xhosas (p < 0.002) and in Zimbabweans (not significant). These data suggest that genetic factors partly explain the clinical and epidemiological variability of rheumatic diseases in black Africans.

Adult↗
PubMed1998

[Platelet alloantigenic systems].

Platelet-specific alloantigen systems are located on glycoproteins expressed at the surface of platelet membrane. These di-allelic systems are due to an amino acid substitution. An official nomenclature was adopted in 1990 by the Working Party on Platelet Serology ICST/ISBT which defined the following rules: (1) platelet-specific antigen systems are called HPA for "Human Platelet Antigens"; (2) they are numbered chronologically according to the date of publication; (3) the most frequent allele is designated by the letter a and the less frequent by the letter b (i.e., HPA-1a 1b). Since the introduction of molecular biology techniques, the nomenclature has become insufficiently precise and an adjustment will probably be required in a near future.

Antigens, Human Platelet↗
PubMed1996

HLA phenotype polymorphism in the Lebanese population.

The HLA-A, -B, -DR and DQ phenotypes have been defined in a panel of 217 Lebanese. These subjects were all unrelated, belonged to different religious communities and originated from the various provinces of Lebanon. All the broad class I specificities tested, except splits A25(10), B54(22) and B56(22), were present in this panel. When HLA-A and -B antigen frequencies were compared with data on the Caucasoids, Negroids and Orientals, several similarities in antigen frequencies could be found between some frequencies observed in the Lebanese and those observed in the Negroids and/or Orientals. There were no frequencies equivalent to those particular to the Caucasoids. In addition, two groups of class I antigens could be distinguished: a first group (A32, B14, B18, B35, B38, B39, B41 and B50) showing higher frequencies, and a second group (A31, B27, B60 and B62) showing lower frequencies than those observed in the Caucasoids, Negroids and Orientals. However, when analysed separately, several mediterranean ethnic groups, notably the Greeks and Italians, have a frequency profile equivalent to that of the Lebanese, with the exception of the B41 specificity, which is particularly high in the Lebanese (14.2%). The data concerning the class II antigens are the most interesting. All the specificities were present in the panel. The HLA-DR5 is the highest frequency of DR antigens in the present panel (58.9%) and nearly all DR5 positive individuals are DR11. The DR11 allele accounts for 33.1% of the total DR gene frequency. The highest DQ antigen frequency is that of DQ3 (76.4%), the majority of which is DQ7 (66.4%). We observed a high DR11-DQ7 haplotype frequency (29.4%) with a significant delta value for linkage disequilibrium. There is no linkage disequilibrium between B41 and DR11. The commonly observed linkage disequilibrium between the DQ5 allele, and the DR1, DR2, DR10 and DR14 alleles are not significant in this Lebanese panel.

Adolescent↗
PubMed1989

Y chromosome DNA polymorphisms in two African populations.

Y chromosome-specific DNA polymorphisms were detected using probe p49f after restriction with TaqI enzyme on samples coming from two African populations: Bantus and Pygmies. All the main TaqI alleles at five Y loci already found in Caucasians are also found in these two populations; 12 of the 16 Caucasian haplotypes were found in these two African populations, and two new haplotypes are Pygmy specific. A proposed phylogeny of the various haplotypes that was derived by using the parsimony criterion established that haplotypes XIII and XVIII, respectively the most frequent one and only one present in Pygmies, are probably ancestral.

Alleles↗
PubMed1987

[Absence of linkage between Alzheimer's disease and a polymorphic probe of the long arm of chromosome 21].

The hypothesis of an eventual linkage between Alzheimer's disease (AD), a presenile dementia, and the genomic probe GMG 21 S3, located on the long arm of chromosome 21, has been investigated in a large family originating from Calabria, in which AD is transmitted as an autosomal dominant mendelian trait. Analysis of the Bgl II restriction polymorphism, after molecular hybridization with the probe, of DNAs coming from 28 subjects of a pedigree, from which 10 individuals are affected, allowed to demonstrate that there wasn't any linkage between AD and the marker studied.

Alzheimer Disease↗
PubMed1987

[Polymorphism of p49 Y-specific probe in Papuas Baruyas of Papua New Guinea].

Taq I polymorphism revealed after molecular hybridization with the Y-specific p49 probe was studied in male Papuas, Baruya tribe, living in the Wonenara valley. All individuals screened were identical at the variable loci A, C, F and I, and fixed for the specific allele Db. The deduced haplotype, number 17 (A2, C0, Db, F1, I1) is Baruya-specific.

Alleles↗
PubMed1986

[Absence of linkage between Alzheimer's disease and the HLA system].

The study of a family in which multiple cases of Alzheimer's disease occurred in several generations offers the opportunity to test the genetic transmission of this disease. The HLA grouping of the members of a pedigree containing 10 affected members allowed to demonstrate that the disease is not due to a single dominant gene linked to the major histocompatibility complex. Although a more complex involvement of the major histocompatibility complex cannot be totally ruled out it is obvious that a strong linkage does not exist between Alzheimer's disease and HLA.

Alzheimer Disease↗
PubMed1981

HLA-A and B antigens in AKA pygmies.

HLA-A and B antigens were studied in 543 AKA pygmies. The present analysis showed two characteristics of this pygmoid group: the absence of HLA-A1, A11, B8 and Bw38 and the high frequency of Aw30, B17, B27, B37, B40 and Bw39. The strongest gametic associations were found with the haplotypes Aw30, B37 and A3, B5.

Black People↗