Search PubMed⌕ Search

Biomedical subjects

D F Roberts

Publications and source records attributed to D F Roberts.

At least 73 records · Page 4Linked to original sources
PubMed1986

Who are the Orcadians?

Gene frequencies from a sample of Orkney islanders relating to red cell blood groups, red cell isoenzymes, serum proteins and HLA types indicate that the Orcadians are situated at the extreme of the European range in many systems. Genetic distance and principal components analyses of gene frequency and relationship matrices suggest that the closest Orcadian affinities are with the North Sea populations rather than with Atlantic. Though their genepool has been modified to some extent by immigrant genes, it is suggested that the Orcadians represent the remains of a relict population, in the same way as, but different from, those of the Gaelic fringe.

Blood Group Antigens↗
PubMed1985

Accuracy of detection of the retinoblastoma gene by esterase D linkage.

The gene for hereditary retinoblastoma (Rb), an autosomal dominant trait localized to the long arm of chromosome 13, is linked to the locus for the enzyme esterase D (EsD). We analyzed a three-generation family that demonstrates cosegregation of alleles at the EsD locus and the Rb locus. This kindred yields a logarithm of the odds ratio (LOD) score of 2.46 at a recombination fraction (0) of 0.0. When combined with five other recently reported families, the resulting maximum score was 11.08 at 0 = 0.0. This combined LOD score and the lack of demonstrable crossovers in more than 65 individuals indicate that predictions of the Rb gene carrier state based on EsD genotyping are at least 90% accurate.

Carboxylesterase↗
PubMed1985

Determinants of plasma alpha 1-acid glycoprotein (AAG) concentrations in health.

The concentration of alpha 1-acid glycoprotein (AAG) was measured in plasma from 200 healthy subjects belonging to 78 family units. The AAG concentration varied markedly between individuals (mean 0.77, range 0.36-1.46 g 1(-1]. When the genetic contribution to the variability was assessed, the only significant correlation observed was that between husband and wife and this was weak. We conclude that in addition to the known effects of age and gender, environmental (rather than genetic) factors largely determine the variance of AAG concentrations.

Adolescent↗
PubMed1985

HLA antigens in Hirschsprung's disease.

In 55 children with Hirschsprung's disease, 64 of their normal siblings and 120 other members of their families, HLA-A, B and C types were examined. The statistical significance of the raised incidence of A1, B14, B37 and Bw35 in the patients disappeared after correction for multiple testing. The levels of homozygosity were very similar in patients and normal controls. The results indicate no direct association of the disease with HLA type.

Child↗
PubMed1984

Cytogenetic studies in spontaneous abortuses.

In a series of 450 products of conception received for cytogenetic analysis, tissue culture was attempted on 309, and karyotypes were established using banding techniques in 154 singleton specimens. Abnormalities of karyotype were identified in 19%; of these abnormalities, 48% were autosomal trisomies. Gestational age was decreased in the abnormal specimens, and their developmental age was retarded by comparison with their gestational age. Factors contributing to the relatively low incidence of abnormality are examined. The major factor appears to be the clinical interest of collaborating staff, leading to selection, either intentional or unintentional, of particular phenotypes and hence a non-random series. A negative relationship is suggested between frequency of monosomy X and autosomal trisomy, both being associated with maternal age.

Abortion, Spontaneous↗
PubMed1984

Multiple sclerosis, HLA, and lymphocyte surface markers.

The frequencies of lymphocytes of different types in the blood of 96 multiple sclerosis patients in different phases of the disease were examined by rosetting, in relation to the HLA antigens present. In the total series of patients, there is a significant deficit of A2, and this is also suggested in the active and progressive cases, but there is no evidence of association of particular HLA haplotypes with the different phases of the disease. There was little variation among the patient categories in the frequency of T cells of different types, but patients in relapse showed a higher proportion of cells showing surface IgG. In general, there is little association of cell surface markers with HLA type, but when B8 is present there appear to be fewer E and EAC rosettes in patients in exacerbation, fewer E and IgG surface markers in remission, and more of the IgG markers in progression.

Antigens, Surface↗
PubMed1984

Serogenetic investigations of two populations of Iran.

Frequencies of 10 polymorphic systems were investigated in two ethnic groups (Turkoman and Bandari) living near the northern and southern borders of Iran, respectively. A further 6 blood group and enzyme systems were also investigated in Bandari alone and 4 in Turkoman alone. 4 out of 10 commonly studied systems (ABO, Rh, AP and Tf) showed significant frequency differences between these populations. Wright's FIS indicates moderate isolation of these groups, and the gene frequency differences are therefore interpreted as indicating the differing origins of these populations.

Blood Group Antigens↗
PubMed1983

Genetic epidemiology.

From the papers in this symposium, an attempt is made to establish the scope and aim of genetic epidemiology. Specifically, its objective is seen as the elucidation of the role of genetic factors in the etiology of a disease whose distribution is related to individual genetic constitution and population genetic structure. A study of multiple sclerosis in the Orkney Islands provides an example.

Environment↗
PubMed1983

HLA antigen frequency in the Koya tribe of Andhra Pradesh, India.

The frequencies of HLA-A, -B, and -C antigens were studied in a tribal population of Koya from Andhra Pradesh in southern India. No other well-defined tribal population has been studied with which the present results may be compared. However, the HLA profile of Koya showed distinct differences from the general HLA distribution in India in the frequency of a large number of antigens both at the A and B loci. This study indicates the distinctiveness of this tribal population and suggests the potential importance of the study of HLA frequencies in tribal groups of India.

Demography↗
PubMed1983

The associations of HLA and other genetic markers with glomerulonephritis.

One hundred and seventy-nine patients with various forms of glomerulonephritis confirmed histologically were tested for HLA A and B antigens: Thirty-four with membranous glomerulonephritis were also typed for DR antigens. One hundred and forty-one of these patients were further tested for blood group, red cell enzyme, and plasma protein systems. The minimal-change and the mesangio-capillary glomerulonephritis showed a significant association with B8 and Bw44 antigens respectively, whereas the membranous nephritis in addition to B8 was also found to be associated with DR3 antigen. Previously described associations with Henoch-Schönlein and Berger's nephritis were not proved. A large group with nonspecific proliferative glomerulonephritis did not show any association with HLA. Among the other single-gene characters studied, a significant association was found with Bf (Factor B or C3 proactivator) and adenosine deaminase, both markers thought to be involved in the immune response. The close association of the markers located on chromosome 6 and glomerulonephritis indicates that there may be an immunological component in the aetiology of the disease. The significance of the various associations found is discussed.

Blood Group Antigens↗
PubMed1983

Some genetic implications of isoelectric focusing of human red cell phosphoglucomutase (PGM1) and serum protein group specific component (Gc): genetic diversity in the populations of Himachal Pradesh, India.

For the study of group specific component (Gc) and phosphoglucomutase (PGM1) polymorphism, isoelectric focusing was performed on eleven tribal and non-tribal populations of Himachal Pradesh, India. They were chosen to illustrate interregional and intraregional variations. The subtype frequencies of these two systems showed clear differences in the genetic constitution of these populations of Himachal at both levels. There is a large increase in the mean heterozygosity (H) for each system by isoelectric focusing over that shown by electrophoresis. Discriminant and distance analyses both suggest that the subtype frequencies provide greater potential for the study of genetic diversity among populations. The data on these additional alleles found by isoelectric focusing are examined for some of their genetic and anthropological implications.

Carrier Proteins↗
PubMed1983

Reflections on muscular dystrophy in a Sudanese kindred.

An extended kindred in the Sudan, where a severe muscular dystrophy has been interpreted as of autosomal recessive inheritance, has been further analysed. The within-sibship ratio, the autosomal and X-linked inbreeding coefficients, and the creatine kinase levels suggest a possible alternative interpretation: X-linked muscular dystrophy with failure of clinical expression in some males.

Adolescent↗
PubMed1983

Genetic analysis of multiple sclerosis in Shetland.

In a family study of all patients with multiple sclerosis in Shetland the number of inbred patients, although high for Britain and higher than in Orkney, is not higher than the number among controls, and the inbreeding coefficients suggest that there is no recessive involvement of rare genes in the aetiology. The kinship coefficients show close interweaving of ancestries of patients and controls and eliminate from the aetiology any involvement of recently introduced single genes dominant or codominant in effect. Family histories show that single locus inheritance is unlikely. Any genetic involvement is likely to be polygenic, but on a multifactorial hypothesis the estimates of heritability are very low. The findings suggest that the genetic contribution to the aetiology of the disease in Shetland is slight.

Consanguinity↗
PubMed1983

Genetic studies in Poland.

Blood specimens were studied from 213 persons aged 3-51 years, in Olkusz, a town between Krakow and Katowice in south Poland. The data show general similarity in blood groups and red cell enzymes to those from other central European populations, but in several systems there are suggestions that Polish frequencies are somewhat peripheral, for example phosphoglucomutase, acid phosphatase, esterase D, while in others where clines exist the results fit well into those expected from the geographical position of the sample.

Adolescent↗