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Biomedical subjects

R L Kirk

Publications and source records attributed to R L Kirk.

At least 19 recordsLinked to original sources
PubMed1992

Genetic affinities of oceanic populations based on RFLP and haplotype analysis of genetic loci on three chromosomes.

Restriction fragment length polymorphisms at the renin and factor 13B loci located at chromosome 1q32-1q42 were studied in 14 ethnic groups in the west Pacific region. The allele frequencies were combined with previously described beta-globin and albumin-vitamin D binding protein haplotype frequencies and used to assess genetic affinities among eight major ethnic-geographic groups in this region. These population groups divide into two clusters with Australian Aborigines, Island Melanesians, and Highland Melanesians forming one cluster and east Asians, Southeast Asians, Micronesians, and Polynesians forming the other. The results indicate that Micronesians and Polynesians are derived from populations in Southeast Asia and that they originated independently of the Melanesian populations.

Beta-Globulins↗
PubMed1990

Albumin--vitamin D-binding protein haplotypes in Asian-Pacific populations.

We have determined the various haplotypic combinations between alleles as well as restriction fragment length polymorphisms of two linked genetic markers, albumin and vitamin D-binding protein or group-specific component, in a number of Asian-Pacific populations. Using the partial maximum likelihood method, we constructed a phylogenetic network from the haplotype frequencies to assess relationships among the populations sampled. No systematic linkage disequilibrium was detected between most of the combinations, suggesting a lack of operation of any selection pressure at the two loci. The phylogenetic analysis confirmed the known interrelationships among various populations in the Asian-Pacific region. The Australian aborigines clustered closely with the non-Austronesian-speaking highlanders from Papua New Guinea, as expected. Similarly, the Austronesian-speaking Polynesians, Micronesians, and the Southeast Asians branched off together as a separate group. The position of the Austronesian-speaking Tolais from New Britain with respect to other populations from the Southwest Pacific was anomalous. The Tolais revealed a strong affinity with the Australian aborigines, which is inexplicable. The populations from China formed a tight cluster with other populations from the Asian-Pacific region. Genetic interrelationships of these populations with the white Australians were remote, which is in accordance with the known affinities of various human racial groups.

Alleles↗
PubMed1990

Evolution of beta-globin haplotypes in human populations.

The beta-globin haplotypes of 852 chromosomes from 12 populations in the Asia-Pacific region are described. These data are combined with those from other populations in an investigation of the affinities of regional human populations. Both partial maximum-likelihood and distance Wagner methods indicate that Africans are the most divergent group, with the remaining populations branching in the following order: Australian Aborigines, Highland Melanesians, Lowland Melanesians, Indonesians and Micronesians, Polynesians, east Asians, Indians, and Europeans. This pattern of relationship is consistent with that indicated by other data. Analysis of the evolution and distribution of haplotype occurrence provides some limited support for an origin of modern humans in Africa. Otherwise, however, it was not useful in further elucidating the evolutionary history of human populations.

Animals↗
PubMed1987

HLA-DR and -DQ DNA genotyping in insulin-dependent diabetes patients in South India.

Restriction fragment length polymorphisms (RFLPs) of the HLA-DR beta, -DQ alpha, -DQ beta, and -DX alpha genes have been examined in South Indian diabetic patients and controls. The DR. DQ linkage arrangements in South Indians were shown to be different for DR2, DR4, and DRw6 from those commonly seen in Europeans, so that localization of the primary disease-promoting gene in IDDM could be attempted. This study clearly implicates at least one DQ beta allele in the pathogenesis of IDDM.

DNA Probes, HLA↗
PubMed1987

Red cell enzyme and serum protein gene markers in Fijians.

A total of 332 persons from three localities in the Fiji Islands have been tested for genetic variation in 24 red cell enzyme systems and 4 serum protein systems. Polymorphic variation was present at 7 red cell enzyme loci and 1 serum protein locus. The remaining systems were invariant except for a single individual with a slow variant at the GOT1 locus and another individual with a D variant at the TF locus. The series from Nandi differed significantly from the Lau Islands for gene frequencies in GPT, ACP and ESD, Koro Island differed from the other localities at the PGD locus and from Nandi for ESD. Genetic distance analysis reveals that Lau Islands cluster with Western Samoa, Koro Island with New Caledonia (Vanuatu), with Nandi being separate.

Blood Proteins↗
PubMed1986

Genetic variants of 6-phosphogluconate dehydrogenase in the Indonesian populations.

Blood samples from 2,091 individuals representing 14 Indonesian populations (11 Austronesian and 3 non-Austronesian speakers) have been tested electrophoretically for 6-phosphogluconate dehydrogenase (6-PGD). Two common alleles, PGDA and PGDC are found in all populations studied, and the phenotype distribution agrees well with the Hardy-Weinberg equilibrium. The PGDC gene frequency varies from as low as 3.5% in the Galelarese to 29% in the Asmat. In general, the PGDC allele seems to decrease in frequency towards the west. A low frequency of PGDC in the Galelarese, a non-Austronesian-speaking population, is thought to be the result of admixture of Austronesian genes, which has not led to language change. In addition to the common alleles, a new variant, PGD A-Lombok, is also described.

Alleles↗
PubMed1985

HLA, complement C2, C4, properdin factor B and glyoxalase types in South Indian diabetics.

A series of diabetic patients from 3 centres in South India have been tested for HLA A, HLA B, BF, C2, C4A, C4B and GLO types. For insulin-dependent diabetes mellitus (IDDM) patients there was a significant increase in HLA B8, of BF F and decrease of C4 A6. No significant variation in HLA, BF, C2 or GLO frequencies was found in non-insulin-dependent diabetes mellitus (NIDDM) patients, but there was a significant decrease in C4B 1 and an increase in C4B 2. The HLA and BF association in South Indian IDDM patients is very different from that reported previously in North India.

Adolescent↗
PubMed1985

Genetic and environmental influence in the epidemiology of noninsulin-dependent diabetes mellitus: a global perspective.

Refinement of the classification of diabetes mellitus to include two major categories, insulin dependent (IDDM) and noninsulin-dependent (NIDDM) and the recent attention paid to the standardization of epidemiological techniques have led to much new information on the epidemiology of the disease. Support for the notion of genetic influence in the development of NIDDM has come from twin studies, but the search for specific genetic markers for NIDDM has been largely unproductive to date. There is increasing scepticism as to the utility of the chlorpropamide-alcohol flush as a genetic marker for NIDDM. The large disparity in the frequency of NIDDM between populations provides indirect support for the genetic hypothesis, as do recent studies of the association between NIDDM and ancestral genetic admixture. Obesity has long been considered a causal factor in the aetiology of NIDDM, though the strength and consistency of this relationship is now being questioned. The strength of the association between obesity and NIDDM has been shown to vary depending on the presence or absence of a family history of the disease. There is further preliminary evidence to suggest that association between obesity and NIDDM may vary in strength between populations, and between the sexes. Little evidence has so far emerged for a role of quantitative or qualitative aspects of diet in the aetiology of NIDDM. This may be due, in part, to the imprecision of current techniques for dietary estimation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1983

Investigation of PGM1(3), PGM1(6), and PGM1(7) variants by isoelectric focusing. Evidence for new subtypes of the PGM1(3) and PGM1(7) alleles.

A total of 345 haemolysates previously phenotyped by starch gel electrophoresis and known to contain the products of the PGM1(3), PGM1(6), and PGM1(7) alleles have been analyzed by thin layer polyacrylamide gel isoelectric focussing in the pH range 5-7. Two common subtypes, 3+ and 3-, of the PGM1(3) allele have been found in a number of Pacific populations. A single form of the PGM1(7) allele was observed in the Western Caroline Islands. In contrast, one of two Indian PGM1(7) variants focussed to a different position when compared with the form found at polymorphic frequency in the Western Caroline Islands. Only one type of the PGM1(6) allele was detected during the present investigation.

Alleles↗
PubMed1979

Hereditary angioedema: lack of close linkage with markers on chromosome 6, with data on other markers.

Members of two Australian families with type A Hereditary Angioedema (HAE), having affected individuals in three generations, were typed for a large number of genetic marker systems in a search for close linkage with the locus controlling C1 inhibitor (C1 inh). The evidence from both families indicated lack of close linkage with HLA or with the loci for Bf and GLO on chromosome 6. Very close linkage was also excluded between the locus for C1 inh and the loci for 6PGD, PGM1 and MNSs. The other markers were not informative, but data on all systems showing variation are reported. The publication of similar data for other kindreds will help to determine lod scores for the probability of linkage between the C1 inh locus and loci controlling common protein polymorphisms. Linkage studies of this kind could establish whether the loci controlling type A and B HAE are identical or separate.

Adult↗
PubMed1979

A true hermaphrodite dispermic chimera with 46,XX and 46,XY karyotypes.

A 16-year-old male with hypospadias and gynaecomastia had a rudimentary uterus with a right Fallopian tube and ovary; the left gonad was a functioning testis. Cytogenetic studies showed cells with 46,XX and 46,XY sex chromosomes in cultured blood, skin and gonadal tissues. Cells with the 46,XX constitution predominated in all tissues. Extensive investigations failed to demonstrate blood cell and serum chimerism, but there was little genetic variation of these characters between family members. Cytogenetic studies demonstrated that the father had contributed different marker chromosomes to the 46,XY and 46,XX cell lines of the propositus, whereas the mother had contributed the same two informative markers to both cell lines. The patient was a chimera with two diploid cell lines of different sex that had developed from the products of two separate acts of syngamy. Dispermy was demonstrated, and, whereas there was no evidence of different maternal contributions to the chimeric cell lines, uncertainty remains that these were identical.

Adolescent↗
PubMed1979

Strong linkage disequilibrium between HLA-Dw2 and and BfS in multiple sclerosis and in the normal population.

An increased frequency of the S allele of Properdin factor B (BfS) was found amongst 162 patients with multiple sclerosis (MS) compared with 470 normal controls. This increase was shown to be due to a strong linkage disequilibrium (LD) between BfS and HLA-Dw2 in 77 patients typed for both systems (delta = 3.84%, P = .0002). The same LD was demonstrated amongst 100 normal controls (delta = 2.24%, P = .0049) and 31 patients with idiopathic demyelination of the peripheral nervous system (IDPN). A total of 70 haplotypes with HLA-Dw2 were encountered (40 MS, seven IDPN and 23 normal controls) and all contained BfS. In the MS patient group, a much weaker association was noted between BfS and HLA-B7 suggesting either that the Bf locus is musch closer to the HLA-D than the HLA-B locus or (and) that HLA-D and Bf products selectively interact (perhaps on the surface of B lymphocytes) with evolutionary advantage or disadvantage resulting from certain allelic combinations. Strong associations between BfS1 and HLA-Bw21 (P = .0000) and BfF1 and HLA-B18 (P = .0001), both previously reported, were confirmed in the current study. No increase in the frequency of a glyoxalase (GLO) allele was found amongst the MS patients and no LD was encountered between HLA-Dw2 and a GLO allele. The possibility that the HLA-Dw2, BfS disequilibrium has resulted from a selective advantage conferred on the general community but at the expense of increasing susceptibility to MS should be considered.

Chromosome Mapping↗
PubMed1979

Genetic susceptibility to diabetes mellitus: the distribution of properdin factor B (Bf) and glyoxalase (GLO) phenotypes.

The distribution of phenotypes controlled by two loci on chromosome 6 has been studied in a series of 239 patients with type 1 (insulin-dependent) and 297 patients with type 2 (non-insulin-dependent) diabetes mellitus. At the properdin factor B (Bf) locus there is a significant increase in the frequency of the BfSu and BfF1 alleles for type 1 patients, and the combined inc;rease in frequency of BfS1 and BfF1 in those patients is highly significant. The relative risk for F1 is 6.2 and for F1 and S1 combined is 5.3. These results confirm the association with F1 reported recently by Raum and co-workers in Boston. The two rare alleles BfS1 and BfF1 are in significant negative disequilibrium with HLA B8. For the glyoxalase (GLO) locus there is a slight but nonsignificant increase in the frequency of the GLO2 allele, but a significant disturbance in the distribution of the GLO phenotypes for type 2 patients. These results for the GLO alleles may be due to stratification in our series of type 2 patients. Further studies are in progress to test this hypothesis.

Alleles↗
PubMed1979

The frequency of private electrophoretic variants in Australian aborigines and indirect estimates of mutation rate.

The number of "private" electrophoretic variants of enzymes controlled by 25 loci has been used to obtain estimates of mutation rate in Australian Aborigines. Three different methods yield values of 6.11 X 10(-6), 2.78 X 10(-6), and 12.86 X 10(-6)/locus per generation for the total sample of Aborigines. One tribal population of Waljbiri in central Australia gives values of 2.99 X 10(-6) and 2.04 X 10(-6) for two of the methods, the third being unapplicable. The mean mutation rate for the total Aboriginal sample of 7.25 X 10(-6) is very similar to the value obtained by Neel and his colleagues for Amerindians in South America.

Australia↗
PubMed1978

Widespread distribution of variant forms of carbonic anhydrase in Australian aboriginals.

Three distinctive genes which control variants of carbonic anhydrase (CA) have been detected in tests on nearly 3000 Aboriginals from various parts of Australia. Two of these genes affect the products of the CA1 locus, the other affects the products of the CA2 locus. In some populations of Aboriginals, more than 10% of persons have a variant carbonic anhydrase. It is suggested that such an unusual frequency of CA variants may be an evolutionary response to metabolic stress connected either with low zinc concentrations in the diet or with the altered needs of ion regulation in an arid environment.

Alleles↗