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PubMed1991

[Investigation of C4 haplotypes in Han nationality of Hubei Province in China].

C4 haplotypes of 93 unrelated families of Han nationality in Hubei Province were determined by means of a method established in our laboratory based on the techniques recommended in the 4th International Workshop for the Genetics of Complement and the method of Carboxypeptidase B developed by Zhang in Australia. 310 C4 haplotypes were analysed. The haplotype frequency of A3B1 (0.4194) was found to be the highest in Han nationality of Hubei in China. The others are as follows: A3B2: 0.1161, A2B1 and A4B2: both 0.0903, AQOB1: 0.0645, A3BQO: 0.0548, AQOBQO: 0.0322, A2B2: 0.0256, A4B1: 0.0161, A2B92: 0.0129. Some kinds of rare haplotypes were also discovered. Significant positive-linkage disequilibrium parameters (delta) were found in haplotypes of A4B2, AQOBQO and A2B92, while the significant negative delta was observed in that of A4B1 and AQOB2. Our data were compared with those of Japanese, Caucasian in USA and Germany, Negroids in South Africa are discussed in the paper. The differences among them.

Asian People↗

PubMed1990

Beta-thalassemia genes in French-Canadians: haplotype and mutation analysis of Portneuf chromosomes.

beta-Thalassemia minor occurs at approximately 1% frequency in French-Canadians--in families residing in Portneuf County (population approximately 40,000) of Quebec province. We found eight different RFLP haplotypes at the beta-globin gene cluster in 37 normal persons and in 12 beta-thalassemia heterozygotes from six families. beta-Thalassemia genes in these families associated with two haplotypes only: Mediterranean I and Mediterranean II. There were two different beta-thalassemia mutations segregating in the Portneuf population: an RNA processing mutation (beta(+)IVS-1,nt110) on haplotype I (five families) and a point mutation leading to chain termination (beta(0) nonsense codon 39) on haplotype II (one family). The distribution of 5' haplotypes on normal beta A Portneuf chromosomes compared with other European populations was most similar to that in British subjects (data for French subjects have not yet been reported). Genealogical reconstructions traced the ancestry of carrier couples to settlers emigrating from several different regions of France to New France in the 17th century. These findings indicate genetic diversity of a greater degree among French-Canadians than recognized heretofore.

DNA Mutational Analysis↗

PubMedDate not supplied

Extended HLA haplotypes in multiplex families with insulin dependent diabetes mellitus in Tunisian population: HLA serological typing and RFLP analysis.

Haplotypes including HLA A, B, C, DR, and DQ were compared in a study population comprising 18 Tunisian multiplex families with diabetic children. Eighty haplotypes found in IDDM patients were compared with 148 haplotypes present in healthy family members. RFLP analysis showed that two DR subtypes were significantly more common in the diabetic haplotypes (DR4-DQw8: 82 per cent in IDDM members compared to 0 per cent in healthy members, p less than 0.001 and DR-Dw25: 56 per cent in IDDM patients compared to 16.7 per cent in healthy members, p less than 0.001) and these were in most cases found in haplotype combinations with HLA A2 B44 DR4 DRw53 and HLA A 24 B18 DR3 genes, respectively.

Diabetes Mellitus, Type 1↗

PubMed1990

The genetics of psoriasis. Haplotype sharing in siblings with the disease.

The purpose of this study was to determine whether the inheritance of psoriasis is HLA linked. We studied 12 families with at least two siblings with psoriasis. We used a sib pair analysis comparing the HLA haplotypes in affected siblings of these families. Haplotype sharing was analyzed in 15 sib pairs; expected frequencies of haplotype sharing were estimated as 25% for HLA identity and 50% for haplotype identity. All sib pairs shared at least one haplotype and 13 of the 15 were HLA identical, compared with the expected frequency of four. These results suggest that at least one, and probably more, HLA-linked genes are implicated in the development of psoriasis.

Disease Susceptibility↗

PubMed1987

Fetal hemoglobin levels and beta (s) globin haplotypes in an Indian populations with sickle cell disease.

To further explore the cause for variation in hemoglobin F (Hb F) levels in sickle cell disease, the beta globin restriction-fragment length polymorphism haplotypes were determined in a total of 303 (126 SS, 141 AS, 17 S beta(0), 7 A beta, (0) and 12 AA) Indians from the state of Orissa. The beta(s) globin gene was found to be linked almost exclusively to a beta(S) haplotype ( -++-), which is also common in Saudi Arabian patients from the Eastern Province (referred to as the Asian beta(s) haplotype). By contrast, the majority of beta A and beta(0) thalassemia globin genes are linked to haplotypes common in all European and Asian populations (+-----[+/-]; --++-++). Family studies showed that there is a genetic factor elevating Hb F levels dominantly in homozygotes (SS). This factor appears to be related to the Asian beta(s) globin haplotype, and a mechanism for its action is discussed. There is also a high prevalence of an independent Swiss type hereditary persistence of fetal hemoglobin (HPFH) determinant active in both the sickle cell trait and in sickle cell disease.

Adolescent↗

PubMed1988

Defective E beta expression in three mouse H-2 haplotypes results from aberrant RNA splicing.

The molecular basis for the defective expression of the mouse class II E beta genes in the H-2w17, H-2q, and H-2f haplotypes has been examined. The results of nuclear run-on transcription and S1 nuclease digestion assays demonstrate that E beta transcription is normal in these haplotypes. Northern blot analyses reveal reduced amounts of E beta RNA of both normal and aberrant size in the w17 and q haplotypes; an even more reduced level of E beta RNA of normal size was detected in the f haplotype. In the preceding study, we reported that the only defect detected in the E beta w17 gene is a single nucleotide insertion in the 5' RNA splice site of the first intervening sequence. S1 nuclease analysis of E beta w17 RNA indicates that splicing at this site is aberrant. One major cryptic RNA splice site is used, leading to reduced amounts of aberrantly processed RNA. Limited use of the mutated splice site and of a second cryptic site also is detected. In all three cases, stop codons in the resulting RNA would prevent their translation. The molecular defect in E beta q appears identical to that of E beta w17. In the f haplotype, even more reduced levels of E beta RNA of both normal and aberrant sizes are found. We thus show that in the three defective E beta alleles, two distinct defects are responsible for the absence of E beta protein synthesis; both of these defects affect RNA processing.

Animals↗

PubMed1989

Molecular analysis of the HLA class II genes in two DRw6-related haplotypes, DRw13 DQw1 and DRw14 DQw3.

We have compared the sequence polymorphism of HLA class II genes of two distinct DRw6 haplotypes. cDNA libraries were constructed from two lymphoblastoid cell lines: CB6B (10w9060) which types as DRw13 DQw1, and AMALA (10w9064) which types as DRw14 DQw3. Multiple sequence differences were found at the DR beta I, DQ alpha, and DQ beta loci when these two haplotypes were compared. The DR beta I allele found in the DRw14 DQw3 haplotype appears to have diverged primarily as a result of a gene conversion event with a DR1 allele acting as donor. In contrast, the DRw13 DQw1 haplotype appears to have arisen by means of a recombination event between the DR and DQ subregions. Thus, multiple genetic mechanisms, including point mutation, gene conversion, and recombination, have generated diversity among DRw6 haplotypes.

Amino Acid Sequence↗

PubMed1989

Typing of MHC haplotypes in OS chicken by means of RFLP analysis.

For the analysis of the genetic background of autoimmune thyroiditis we used the Obese strain (OS) chicken model which develops a SAT. Practically all animals from this strain show severe lymphoid infiltration of the thyroid gland and circulating autoantibodies against thyroglobulin (Tg-AAb) within a few weeks after hatching. Of the 3 MHC haplotypes (B5, B13, B15) present in the OS, B13 was mostly associated with severe thyroid infiltration. Haplotypes B5 and B15 were associated both with severe, as well as with mild infiltration. To clarify these controversial results published by different groups and to further assess the role of the MHC in the development of SAT, we selected by appropriate breeding sublines with high and low levels of Tg-AAb. With the help of serological methods and GvH assays we were not able to find additional differences in the MHC antigens of that line. Therefore, for further characterization of these haplotypes, RFLP analysis was applied in the present study. Southern blots were done with restriction enzyme digests of erythrocyte DNA hybridized with a chicken cDNA probe (code-p234) for MHC class II antigens. The Southern blots with BamH-I digests showed at least 5 bands, four of which were polymorphic. Four RFLP patterns emerged, two of which were observed within chickens with the B15 haplotype. The confirmation of this RFLP heterogeneity within serologically identical haplotypes requires additional analysis.

Animals↗

PubMed1989

[Genetic analysis of complementation of t-haplotypes in mice].

Complementation for viability of the compounds tx/ty in complete lethal haplotypes t6, t12, tw5, tw12, tw18, tw73, twPa-1 belonging to the seven basic complementation groups was studied. In the overwhelming majority of crosses a lack of tx/ty offspring was revealed but there is also evidence of non-complete complementation of the tx/ty haplotypes, except for T/tw73XT/tw12, T/tw18XT/t12, T/tw73XT/tw18 crosses in which the level of complementation for viability exceeds 100%. The maternal effect for compound variability was significantly revealed in 9 out of the 19 matings. In addition, reciprocal matings of heterozygotes T/txXT/ty were tested for fertility. In two cases, the maternal effect was also revealed for this character. Comparison of data on viability of the compounds and the fertility of the original strains gives grounds to believe that the tx/ty haplotypes are not completely recessive and partially manifest themselves in the heterozygotes, decreasing fertility in a number of matings. In some cases, these t-haplotypes yield an effect, close to negative complementation, which may be associated with the interaction of the proteins of t-haplotypes.

Animals↗

PubMed1987

Possible association of specific HLA haplotype in a pedigree with familial polyposis coli.

HLA-A, -B, -C, and -DR typing was performed in a pedigree with familial polyposis coli (FPC). Three living members with FPC and one member without obvious FPC had the same HLA haplotype; A24(9)-B51-X-DRw8 (X indicates undetected HLA-C locus). It was genetically deduced that a deceased member with FPC also had this haplotype. No other members had this haplotype. No association was found between FPC and other HLA haplotypes. Thus an association between the specific HLA haplotype and FPC was suspected in this family.

Adenomatous Polyposis Coli↗

PubMed1988

[Haplotypes associated with the cystic fibrosis gene (CF)].

The linkage relationships between the cystic fibrosis locus and six marker loci allowed us to build 122 haplotypes bearing the CF gene and to compare them to the 122 normal haplotypes. We obtained 13 different marker haplotypes associated with the CF chromosomes and 22 with the normals in our population. To examine the possibility of a correlation between the clinical and the genetical polymorphism of the disease haplotype analysis was carried out taking in account age at diagnosis, severity of the disease and a particular clinical subgroup such as meconium ileus or pancreatic sufficiency. The results showed that a particular haplotype (121) is predominant in the severe form of the disease. This may have implication in diagnosis and prognosis of the disease.

Chromosomes, Human, Pair 7↗

PubMed1986

Implantation of cultured thymic fragments in congenitally athymic nude rats: ignorance of thymic epithelial haplotype in generation of alloreactivity.

We studied the development of thymus-dependent immunity in congenitally athymic nude rats after implantation of cultured thymic fragments (CTF), particularly the development of in vitro alloreactivity in allogeneic combinations. CTF of DA (RT1a), PVG (RT1c), and RP (RT1p(u,1] origin were implanted in nude rats of WAG (RT1u) origin. In analysis 14 to 18 wk later, all recipients exhibited thymus-dependent immunocompetence assessed by (immuno)-histology of lymphoid organs and responsiveness to in vitro concanavalin A stimulation and in vivo ovalbumin immunization. Control nude animals were unresponsive. Also, in vitro alloreactivity was observed, measured by mixed lymphocyte reaction and cell-mediated lympholysis. The alloresponse to the allogeneic CTF donor haplotype was as to a third party, but that to the recipient was negative. The CTF before implantation were devoid of lymphoid elements and revealed epithelial-like cells as the major component. Cells in CTF showed expression of RT1 class I and class II antigens. CTF at autopsy had the architecture of a normal thymus. In immunohistochemistry using haplotype-specific antibodies, lymphocytes showed RT1u class I expression as in the normal WAG thymus. In the cortex-like area of CTF, stromal cells revealed class I and class II haplotype expression of the donor thymus, but in the medulla-like area, class II haplotype expression was that of the recipient WAG rat. These data indicate that after implantation in nude rats, CTF become populated not only with lymphoid elements, but also with stromal components from the recipient. In induction of thymus-dependent immunity, these acceptor-derived stromal (dendritic) cells may be involved in generation of allospecificity; class I and class II haplotype expression by the donor cortex (epithelial) compartment is ignored in this process.

Animals↗

PubMed1994

Founder mitochondrial haplotypes in Amerindian populations.

It had been proposed that the colonization of the New World took place by three successive migrations from northeastern Asia. The first one gave rise to Amerindians (Paleo-Indians), the second and third ones to Nadene and Aleut-Eskimo, respectively. Variation in mtDNA has been used to infer the demographic structure of the Amerindian ancestors. The study of RFLP all along the mtDNA and the analysis of nucleotide substitutions in the D-loop region of the mitochondrial genome apparently indicate that most or all full-blooded Amerindians cluster in one of four different mitochondrial haplotypes that are considered to represent the founder maternal lineages of Paleo-Indians. We have studied the mtDNA diversity in 109 Amerindians belonging to 3 different tribes, and we have reanalyzed the published data on 482 individuals from 18 other tribes. Our study confirms the existence of four major Amerindian haplotypes. However, we also found evidence supporting the existence of several other potential founder haplotypes or haplotype subsets in addition to the four ancestral lineages reported. Confirmation of a relatively high number of founder haplotypes would indicate that early migration into America was not accompanied by a severe genetic bottleneck.

Americas↗

PubMed1995

Variants of HLA-DR2/DR51 group haplotypes and susceptibility to tuberculoid leprosy and pulmonary tuberculosis in Asian Indians.

This study reports our observations on the correlation between HLA-DR2 subtypes and their DR-DQ haplotypes in patients with tuberculoid (TT) leprosy and pulmonary tuberculosis (PTB). DRB1*1501 was significantly increased in patients with PTB (90%) as compared to controls (p < 0.05); whereas the prevalence of DRB1*1502 was significantly increased in patients with TT leprosy (p < 0.05), suggesting allele-specific binding of the pathogen to form disease-causing motifs to the T-cell receptor. Among DR2-DQ haplotypes, the deviation was noted in the distribution of unique and common haplotypes in patients with TT leprosy and PTB. A significant decrease of haplotype DRB1*1501-DRB5*0101-DQA1*0102-DQB1*0502 in TT leprosy and a significant increase of DRB1*1501-DRB5*0101-DQA1*0103-DQB1*0601 in PTB patients were observed. The occurrence of specific DR2 subtypes and their haplotypes in the two disease groups suggests their involvement in disease pathogenesis.

Adult↗

PubMed1995

[HLA haplotypes in families of children with congenital adrenal hyperplasia].

The haplotypes of class I HLA system were determined in a group of 32 children with congenital adrenal hyperplasia and classic form of 21-hydroxylase deficiency. The haplotype frequencies were analyzed and compared to those of the control population. Haplotypes containing the HLA-B-47 antigen were significantly more frequent among the families of patients than among the control population. Among the patients, haplotypes HLA A3-B47-Cw6 and HLA A3-B47-Cwx constituted 50% of all the observed haplotypes with the HLA-B47 antigen. It is stressed that the frequency of homozygotic systems for antigens determined by locus HLA-A (33.34%) and for antigens with locus HLA-B (22.23) were much higher in the affected children.

Adrenal Hyperplasia, Congenital↗

PubMed1995

[Genetic and molecular analysis of new recombinant t-haplotypes t(M8) and t(M9)].

The results of genetic and molecular analysis of new recombinant mouse haplotypes tM8 and tM9, derived from tw12 and t12, are described. Data on viability and fertility of tM/tM homozygotes are presented, as well as that on t-chromosome transmission ratio distortion (TRD) in the progeny of heterozygous males. Blot-hybridization analysis was performed using four t-specific probes: Tu48, Tu66, Tu119, and Tu122. Comparison of data obtained in the study with that on the structure of the initial haplotypes suggests that both recombinant haplotypes resulted from unequal crossing-over. In the case of tM9 haplotype, the crossing-over site was probably located in the region of distal t complex inversion, and tM8 haplotype resulted from two crossing-over events in the medial part of t complex.

Animals↗

PubMed1995

Induction of tolerance to renal allografts across single-haplotype MHC disparities in miniature swine.

We have previously demonstrated that a 12-day course of cyclosporine A (CsA) leads to the induction of tolerance to renal allografts in 100% of recipients selectively mismatched at class I for both haplotypes, and in 71% of recipients selectively mismatched at class II for both haplotypes, but in 0% of recipients mismatched for two haplotypes at both class I and class II. We have postulated that the mechanism by which tolerance is induced may therefore require matching for either class I or class II antigens. One might predict from this hypothesis that tolerance would also be induced in donor-recipient combinations sharing one full haplotype (e.g., AC-->AD), which mimics the clinically relevant transplant combination of parent to offspring. We have therefore investigated the effects of the CsA regimen on renal transplants in this combination. Without immunosuppression, such kidney allografts were uniformly rejected (n = 12; 10.6 +/- 2.4 days). In contrast, a course of CsA (10-13 mg/kg/day) during the first 12 postoperative days induced long-term acceptance of the allograft in 67% (4/6) of recipients. Some acceptor animals also showed specific unresponsiveness to donor antigens as measured by in vitro assays and by failure to develop anti-donor antibodies. Tolerance was confirmed in four of these animals by failure to reject a second transplant SLA-matched to the first kidney donor without additional immunosuppression. These results suggest the feasibility of inducing specific tolerance across a single-haplotype mismatch in the majority of the cases, which could have clinical implications for living-related transplants.

Animals↗

PubMed1994

Analysis of HLA class II haplotypes in the Cayapa Indians of Ecuador: a novel DRB1 allele reveals evidence for convergent evolution and balancing selection at position 86.

PCR amplification, oligonucleotide probe typing, and sequencing were used to analyze the HLA class II loci (DRB1, DQA1, DQB1, and DPB1) of an isolated South Amerindian tribe. Here we report HLA class II variation, including the identification of a new DRB1 allele, several novel DR/DQ haplotypes, and an unusual distribution of DPB1 alleles, among the Cayapa Indians (N = 100) of Ecuador. A general reduction of HLA class II allelic variation in the Cayapa is consistent with a population bottle-neck during the colonization of the Americas. The new Cayapa DRB1 allele, DRB1*08042, which arose by a G-->T point mutation in the parental DRB1*0802, contains a novel Val codon (GTT) at position 86. The generation of DRB1*08042 (Val-86) from DRB1*0802 (Gly-86) in the Cayapa, by a different mechanism than the (GT-->TG) change in the creation of DRB1*08041 (Val-86) from DRB1*0802 in Africa, implicates selection in the convergent evolution of position 86 DR beta variants. The DRB1*08042 allele has not been found in > 1,800 Amerindian haplotypes and thus presumably arose after the Cayapa separated from other South American Amerindians. Selection pressure for increased haplotype diversity can be inferred in the generation and maintenance of three new DRB1*08042 haplotypes and several novel DR/DQ haplotypes in this population. The DPB1 allelic distribution in the Cayapa is also extraordinary, with two alleles, DPB1*1401, a very rare allele in North American Amerindian populations, and DPB1*0402, the most common Amerindian DPB1 allele, constituting 89% of the Cayapa DPB1.(ABSTRACT TRUNCATED AT 250 WORDS)

Alleles↗