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Biomedical subjects

S S Papiha

Publications and source records attributed to S S Papiha.

At least 19 recordsLinked to original sources

Association of Wegener's granulomatosis with HLA antigens and other genetic markers.

The frequencies of the HLA-A, B, C, DR, DQ antigens and of several other genetic markers in biopsy proved and well characterised patients with Wegener's granulomatosis were compared with control frequencies of the region. A highly significant increase in HLA-DR1 was found. The percentage combined frequency of DR1-DQw1 was significantly higher in patients than in the controls. Interestingly, association with the red cell enzyme GLOI and complement locus C4B was also seen. As both of these markers are either linked or within the major histocompatibility complex region (MHC) this is further evidence for the involvement of chromosome 6 in the pathogenesis of Wegener's granulomatosis. To understand the pathology of the disease fully molecular genetic studies of the MHC region are warranted.

Adult

Origin of the Romany gypsies--genetic evidence.

Genetic heterogeneity and affinity was examined between nine Romany speaking gypsy populations and two of their possible ancestral populations from India. For AB0, Rhesus (D), MN and HP systems there exists a conclusive heterogeneity among these populations. Three gypsy populations from Western Europe (English, Welsh and Swedish) are genetically distinct from the rest of the East European gypsies and the populations of India analysed in this investigation. Overall the genetic differentiation among these populations is moderately high (RST = 0.029). The results also indicate the relative close relationship among the East gypsies and the two selected nomadic populations of India. The factors responsible for the moderate diversification of the East European gypsies may be high rate of migration, isolation and random drift, while among the Western gypsy populations admixture seems to be an important differentiation factor.

Adult

Mapping of the Darier's disease gene by serogenetic markers: results in two large British kindreds.

The authors have carried out genetic linkage studies in 57 subjects from two large kindreds of Darier's disease, using a range of serological and biochemical polymorphisms of known chromosomal location. In these kindreds, about 7% of the genome has been excluded for close linkage to the Darier's disease gene. However, one family showed positive lod scores for linkage with the Duffy blood locus (1p13); lod scores were negative in the other family, but in the combined families the total score for this marker was still positive and does not completely exclude linkage.

Chromosome Mapping

Population variation in molecular polymorphisms of the short arm of the human X chromosome.

Five DNA probes (RC8, 754, XJ 1-1, pert 87.8, and L1.28) from the short arm of the human X chromosome were investigated in samples from five populations (English, Nigerian, Chinese, Muslim, and Hindu from India). The variation in the allele frequencies of several probes between different groups was significant. The average heterozygosity in females of the five populations ranged from 32% to 51%. The genetic distance between the five groups was compatible with that using traditional polymorphic systems. There is an interesting suggestion of longitudinal cline for allele *2 (9 kb) detected with probe L1.28. The X-linked RFLPs are useful genetic markers for anthropological studies.

Alleles

Factor B (BF) allotypes and multiple sclerosis in north-east England.

A significant decrease in the frequency of BF*F allele and an increase of BF*F1 allele was found in 101 clinically definite multiple sclerosis patients compared to 270 normal controls from North-East England. In Dw2 types 41 patients and 60 controls, only the rare allele BF*F1 showed a significant increase in the patients group. For the common BF*S allele a significant increase was found in Dw2+ patients compared to the Dw2- patients, but a slight similar increase observed in Dw2+ controls did not attain significance. This increase in the patient group is attributed to a strong linkage disequilibrium between BF*S and Dw2 alleles. No such linkage disequilibrium exists in the normal controls. There is a suggestion that the BF*S and Dw2+ alleles are more prevalent in chronic progressive patients, implying that in Dw2+ patients BF may influence the progression of the disease.

Alleles

Serogenetic studies of the Lobanas in north-west India.

Phenotype and gene frequencies of several polymorphic genetic markers were examined in a Sikh agriculturist caste group, Lobanas of Punjab, India. Lobanas have been a trading community, now settled as cultivators, but for their origin there have been a difference of opinions. To trace their genetic relationship the gene frequency data was compared using multivariate analysis with several populations of India, which historically shared not only a common life style but also have a synonymous meaning of Lobana. The results of the study showed a conclusive genetic heterogeneity of Lobanas compared to the populations of North West and South India. While there is a suggestion that the differences in genetic structure of Lobanas may be due to their historical affiliation but the overall genetic diversity in this population may also be influenced by inbreeding, admixture and selection due to change in socio-economic factors.

ABO Blood-Group System

No evidence for linkage between late onset autosomal dominant retinitis pigmentosa and chromosome 3 locus D3S47 (C17): evidence for genetic heterogeneity.

Retinitis pigmentosa is an inherited form of blindness caused by progressive retinal degeneration. P. McWilliam et al. (1989, Genomics 5: 619-622) demonstrated close genetic linkage between autosomal dominant retinitis pigmentosa (ADRP) and locus D3S47 (C17) in a single early onset pedigree. The marker C17 maps to the long arm of chromosome 3. Clinically, the disease phenotype has been subdivided into at least two forms on the basis of age of onset, as well as electrodiagnostic criteria. We demonstrate that C17 is unlinked in a late onset pedigree, indicating that the phenotypic variation seen reflects underlying genetic heterogeneity.

Chromosomes, Human, Pair 3

Linkage to D3S47 (C17) in one large autosomal dominant retinitis pigmentosa family and exclusion in another: confirmation of genetic heterogeneity.

Recently Dryja and his co-workers observed a mutation in the 23d codon of the rhodopsin gene in a proportion of autosomal dominant retinitis pigmentosa (ADRP) patients. Linkage analysis with a rhodopsin-linked probe C17 (D3S47) was carried out in two large British ADRP families, one with diffuse-type (D-type) RP and the other with regional-type (R-type) RP. Significantly positive lod scores (lod score maximum [Zmax] = +5.58 at recombination fraction [theta] = .0) were obtained between C17 and our D-type ADRP family showing complete penetrance. Sequence and oligonucleotide analysis has, however, shown that no point mutation at the 23d codon exists in affected individuals in our complete-penetrance pedigree, indicating that another rhodopsin mutation is probably responsible for ADRP in this family. Significantly negative lod scores (Z less than -2 at theta = .045) were, however, obtained between C17 and our R-type family which showed incomplete penetrance. Previous results presented by this laboratory also showed no linkage between C17 and another large British R-type ADRP family with incomplete penetrance. This confirms genetic heterogeneity. Some types of ADRP are being caused by different mutations in the rhodopsin locus (3q21-24) or another tightly linked gene in this region, while other types of ADRP are the result of mutations elsewhere in the genome.

Base Sequence

Serogenetic investigations of Tibetans and Himachalis from Himachal Pradesh, India: genetic relationship between Tibetans and certain selected mongoloid populations.

Twenty two serogenetic systems were investigated in 115 Tibetans and 128 Himachalis from the state of Himachal Pradesh, northwest India. For eight of the loci (ABO, Rh, MNSs, P, Fy, 6PGD, EsD, and AK) the two populations showed conclusive heterogeneity and their frequency distribution showed that the serogenetic differences between two populations are due to their different racial affiliations. The Tibetans were also analysed for their genetic relationship with certain selected populations from the Cis-Himalayan, far east and south Asian regions. The calculations of the Harpending's kinship matrix R and the genetic distances showed that the Tibetans are closer to the mongoloid populations of the Cis-Himalayan region and the differences in the present day population structure of the mongoloid groups of this region are more likely to be due to differential migration, admixture and racial affiliation although there is a slight possibility of disruptive selection for certain loci such as 6PGD and AK which showed an exceptionally high value of Canning (6PGD*C) and AK*1 genes.

Asian People

PHA-induced interferon in multiple sclerosis: association between gamma interferon and clinical and genetical variables.

Gamma interferon (INF-gamma) production, after PHA stimulation of peripheral blood mononuclear cells, from multiple sclerosis (MS) patients with the acute remitting and chronic progressive forms, in attack and remission phases, and from normal controls, was studied by immunoradiometric assay. MS patients in all these 4 clinical states of disease produced less INF-gamma (log value range from 2.55 to 2.65). MNC from the total MS patients produced significantly low levels of INF-gamma compared to the control group (log values 2.60 vs. 2.82; P = 0.001). No association between the interferon production and antigens at any HLA locus (A, B, C, Dw and Bf) was found. There was no correlation between IFN-gamma production and age, sex, duration of disease, or disability index. However there was a slight tendency to negative correlation with the progression index of the disease. The results suggest that this lower IFN-gamma production in MS may be secondary to the disease, and the primary defect may be a severe reduction of the essential lymphocyte populations required for an effective lymphokine cascade to produce the normal immune response against infection.

Adult

Alpha 1 antitrypsin (PI) phenotypes in two rheumatic diseases: a reappraisal of the association of PI subtypes in rheumatoid arthritis.

alpha 1 Antitrypsin phenotypes were determined by isoelectric focusing in 225 adult white patients with rheumatoid arthritis (RA), 60 patients with severe rheumatoid arthritis (grade III and IV), 17 sibling pairs--HLA identical but discordant for rheumatoid arthritis, and 122 random patients with Sjögren's syndrome. No significant increase in non-M phenotypes was found in either of the groups of patients with RA, but the association between M subvariants was striking. There was a significant increase in M1M2 phenotype and M2 allotype in both the RA and severe RA groups. This increase in M1M2 was also supported by DR4 positive patients with RA compared with DR4 positive siblings without RA. No apparent association of variant phenotype was found in four subgroups of patients with Sjögren's syndrome.

Alleles

Population frequencies of three DNA alleles linked to the Duchenne muscular dystrophy gene.

To enquire whether the known X linked probes linked to the Duchenne muscular dystrophy gene vary in their RFLP frequencies, three probes, 754, XJ1.1, and pERT87.8, were tested in European, Indian Muslim, and West African samples. Though the average heterozygosity for the three together is fairly similar in the three populations, significant differences in allele frequencies were evident.

Alleles

Serum proteins and erythrocyte enzymes of populations in Iran.

The genetic polymorphisms of nine biochemical genetic markers were investigated in four populations (Turks, Kurds, Tehranis and Kermanis) living in the north-east and south-east regions of Iran. Only one of the nine loci studied (acid phosphatase) showed significant gene frequency differences and for the C3 system the F allele frequencies in these populations were the lowest ever reported from Iran.

Blood Proteins

Polymorphism of serum proteins (C3, BF, HP and TF) of six populations in Colombia.

Five hundred and eighty-five serum samples from six populations in Colombia (Baranoa, Choco, Uitoto Indians, Subachoque, Pasto and Urban Bogotan) were investigated for four genetic markers. For the HP, C3 and BF systems but not for TF there is a wide range of gene frequency variation and these differences are compared with those in the few previous studies.

Black People

HLA antigens in three populations of India.

In blood samples from a Hindu population of Uttar Pradesh (North India) and from two Muslim groups, one from Andhra Pradesh (South India) and the other from Gujurat (West India), frequencies of 38 HLA-A, -B and -C antigens were investigated. Eight antigens - A23, A25, A29, A32, Bw45, B21, Bw22 and Bw53 - were absent in the Hindu population, four different antigens - A29, Bw52, B14 and Bw42 - were absent in Hyderabad Muslims, two antigens - A31 and Bw45 - were lacking in Surat Muslims. The three populations showed considerable genetic heterogeneity. The genetic difference between the two Muslim groups was small, but the Hindu population showed pronounced differences from each of the Muslim groups.

Gene Frequency