Global microRNA profiles in cervical squamous cell carcinoma depend on Drosha expression levels

Gain of chromosome 5p is seen in over 50% of advanced cervical squamous cell carcinomas (SCCs), although the genes responsible for the selective advantage provided by this abnormality are poorly understood. In the W12 cervical carcinogenesis model, we observed that 5p gain was rapidly selected over approximately 15 population doublings and was associated with the acquisition of a growth advantage and invasiveness. The most significantly upregulated transcript following 5p gain was the microRNA (miRNA) processor Drosha. In clinically progressed cervical SCC, Drosha copy-number gain was seen in 21/36 clinical samples and 8/10 cell lines and there was a significant association between Drosha transcript levels and copy-number gain. Other genes in the miRNA processing pathway, DGCR8, XPO5 and Dicer, showed infrequent copy-number gain and over-expression. Drosha copy-number and expression were not elevated in pre-malignant cervical squamous intraepithelial lesions. Importantly, global miRNA profiling showed that Drosha over-expression in cervical SCC appears to be of functional significance. Unsupervised principal component analysis of a mixed panel of cervical SCC cell lines and clinical specimens showed clear separation according to Drosha over-expression. miRNAs most significantly associated with Drosha over-expression are implicated in carcinogenesis in other tissues, suggesting that they regulate fundamental processes in neoplastic progression. Our evidence suggests that copy-number driven over-expression of Drosha and consequent changes in miRNAs are likely to be important contributors to the selective advantage provided by 5p gain in cervical neoplastic progression.

Gain and overexpression of the oncostatin M receptor occur frequently in cervical squamous cell carcinoma and are associated with adverse clinical outcome

For many oncogenes, increased expression resulting from copy number gain confers a selective advantage to cells that consequently make up the tumour bulk. To identify oncogenes of potential biological significance in cervical squamous cell carcinoma (SCC), 36 primary samples and ten cell lines were screened by array comparative genomic hybridization (CGH). The most commonly occurring regions of copy number gain that also showed amplification were 5p15.2-14.3 (59%), 5p13.3 (65%), and 5p13.2-13.1 (63%). Gene copy numbers were significantly associated with expression levels for three candidate oncogenes at these loci: OSMR (oncostatin M receptor) (p=0.03), PDZK3 (PDZ domain containing protein 3) (p=0.04), and TRIO (triple functional domain) (p=0.03). Further examination by fluorescence in situ hybridization on a tissue microarray of 110 primary cervical SCC samples revealed copy number gain frequencies of 60.9%, 57.3%, and 54.5% for OSMR, PDZK3, and TRIO, respectively, with OSMR adversely influencing overall patient survival independently of tumour stage (p=0.046). By array CGH, copy number gain of OSMR was not seen in any of 40 microdissected precursor cervical squamous intraepithelial lesions (SILs). Moreover, global mRNA expression analysis, using Affymetrix U133A 2.0 Arrays, showed no overexpression of OSMR in SILs, suggesting that OSMR gain and overexpression are relatively late steps in cervical carcinogenesis. In the cervical SCC cell lines CaSki and SW756, exogenous OSM activated downstream-signalling elements of OSMR including STAT3, p44/42 MAPK, and S6 ribosomal protein, and induced transcription of the angiogenic factor VEGF, effects that were reduced by OSMR depletion using RNA interference. We conclude that copy number gain of OSMR is frequently found in cervical SCC and is associated with adverse clinical outcome. As well as being a potential prognostic marker, OSMR is a candidate cell surface therapeutic target.

Semi-physiological pharmacokinetic-pharmacodynamic (PK/PD) models for troxacitabine-induced neutropenia and thrombocytopenia

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Background: Neutropenia and thrombocytopenia are the dose-limiting toxicities of troxacitabine in Phase 1 studies. The present study’s aim was to develop a novel semi-physiological PK/PD model that can simultaneously describe the time course of the absolute neutrophil and platelet count changes in cancer patients receiving troxacitabine. Methods: The mixed-effect modeling was performed using the Monte-Carlo Parametric Expectation Maximization algorithm implemented in SADAPT program. The analysis was based on PK/PD data from 31 subjects who received troxacitabine/cisplatin combination every 28 days at five different dose levels (4.8/50, 4.8/75, 6.4/50, 6.4/75, 8.0/75 mg/m2). The PD model consisted of 1) a troxicatabine-sensitive uncommitted progenitor cell compartment, which differentiates into committed neutrophil and platelet progenitor cells that are also sensitive to the troxacitabine, and 2) transit compartments for neutrophils and platelets that represent maturation stages in bone marrow. To capture the rebound phenomena and maintain the hemostasis, the model included a feedback mechanism for both neutrophils and platelets. The troxacitabine concentrationtion-time profiles affected the proliferation of sensitive progenitor cells through an inhibitory sigmoidal Emax model. A three-compartment linear pharmacokinetic model was developed to describe the troxaicibatine concentration-time profile. Results: The PD model described the time-course of troxacitabine- induced neutrophil and platelet cytopenias and accounted for the large observed inter-patient variability. The model predicted that neutrophil progenitor cells were more sensitive to troxacitabine therapy compared to platelet progenitor cells. Furthermore, the model suggested that the troxacitabine-induced neutropenia and thrombocytopenia are reversible and non-cumulative events. Conclusions: This novel model can describe both the intensity and duration of troxacitabine-induced thrombocytopenia and neutropenia rather than simply considering the nadir values. It may be valuable for selecting treatment regimens that minimize troxacitabine’s dose-limiting hematological toxicities.

No significant financial relationships to disclose.

MCM immunocytochemistry as a first line cervical screening test in developing countries: a prospective cohort study in a regional cancer centre in India

Cervical screening is not available for the majority of women in resource-poor countries. An important factor is a lack of skilled operators necessary for high-throughput assessment of the Papanicolaou (Pap) test currently in use. We compared the efficacy of immunocytochemistry for minichromosome maintenance (MCM) proteins vs standard Pap testing at detecting disease in 455 cervical smears processed in a typical Indian screening laboratory. Conventional (non-monolayer) smears were stained manually and then examined by a cytotechnologist and a cytopathologist. The MCM test was called positive when immunolabelled cells were identified as dyskaryotic by the Pap counterstain. The MCM test was read more quickly than the Pap test (approximately 2 vs 10 min) and there was 100% inter-observer agreement compared with 85% for Pap (P<0.0001). The MCM test detected 10 biopsy-proven cancers or pre-cancers that were not detected by Pap (P=0.002; P=0.016 excluding three cases where the Pap was deemed unsatisfactory on review). The cases in question included one recurrent squamous carcinoma and one adenocarcinoma in a screening patient who would have returned to 5 year recall. There were no false positive MCM test results. We propose that MCM immunocytochemistry has considerable advantages for cervical screening in developing countries like India.

Prevalence of MRSA in Emergency and Elective Patients Admitted to a Vascular Surgical Unit: Implications for Antibiotic Prophylaxis

OBJECTIVES

MATERIALS AND METHODS

200 consecutive emergency/transfer and 150 consecutive elective patients admitted between April 2004 and January 2005, were studied. Data was obtained from departmental Morbidity and Mortality records and the computerised laboratory medicine information system.

RESULTS

261 (75%) of the 350 patients were screened for MRSA on admission (target 100%). The proportions of emergency/transfer and elective patients screened were similar (78% and 72% respectively). The prevalence of MRSA carriage detected by admission screening in emergency/transfer patients 30/153 (20%), was significantly higher (p<0.0001) than in elective patients 2/108 (2%). A simple decision analysis model suggests that gentamicin should be used when the prevalence of MRSA reaches 10% and vancomycin when the prevalence reaches 50%.

CONCLUSIONS

The high prevalence of MRSA colonisation in emergency/transfer patients has important implications for pre-operative antibiotic prophylaxis.

Analysis of imprinted genes in subjects with Prader-Willi syndrome and chromosome 15 abnormalities

PURPOSE

To determine gene expression of five imprinted genes or transcripts from the 15q11-q13 chromosome region using reverse transcription polymerase chain reaction (RT-PCR) in a relatively large survey of Prader-Willi syndrome (PWS) and control subjects with several different chromosome 15 abnormalities.

METHODS

RT-PCR was undertaken on mRNA isolated from tissue (e.g., mostly lymphoblasts) from 38 PWS and 10 control subjects. DNA primers were used for five imprinted genes or transcripts (ZNF127, SNRPN, PAR5, IPW, and PAR1) from 15q11-q13 and fibrillin, a control gene from 15q21.

RESULTS

One PWS subject with maternal disomy 15 showed weak but detectable expression of PAR1, whereas SNRPN expression was detected in two PWS subjects [one with the 15q11-q13 deletion and one with a t(15;15) karyotype and maternal disomy 15], and the remaining typical PWS subjects showed no expression of the imprinted genes or transcripts.

CONCLUSION

No obvious clinical differences were identified in those PWS subjects with weak expression of genes compared with those showing no expression. Although the reason(s) for weak expression is unknown, possible explanations include relaxation of imprinting caused by failure to reset the imprinted genes or transcripts in the maternal germ line or by postzygotic gene expression or undetected chromosome 15 mosaicism in the deletion PWS subjects. The timing, tissue source, and other factors relating to partial expression of genes that are thought to be imprinted may play a role in clinical variability and allow for a better understanding of molecular mechanisms in PWS and other abnormalities of proximal chromosome 15q.

Imprinting-mutation mechanisms in Prader-Willi syndrome

Microdeletions of a region termed the "imprinting center" (IC) in chromosome 15q11-q13 have been identified in several families with Prader-Willi syndrome (PWS) or Angelman syndrome who show epigenetic inheritance for this region that is consistent with a mutation in the imprinting process. The IC controls resetting of parental imprints in 15q11-q13 during gametogenesis. We have identified a larger series of cases of familial PWS, including one case with a deletion of only 7.5 kb, that narrows the PWS critical region to <4. 3 kb spanning the SNRPN gene CpG island and exon 1. Identification of a strong DNase I hypersensitive site, specific for the paternal allele, and six evolutionarily conserved (human-mouse) sequences that are potential transcription-factor binding sites is consistent with this region defining the SNRPN gene promoter. These findings suggest that promoter elements at SNRPN play a key role in the initiation of imprint switching during spermatogenesis. We also identified three patients with sporadic PWS who have an imprinting mutation (IM) and no detectable mutation in the IC. An inherited 15q11-q13 mutation or a trans-factor gene mutation are unlikely; thus, the disease in these patients may arise from a developmental or stochastic failure to switch the maternal-to-paternal imprint during parental spermatogenesis. These studies allow a better understanding of a novel mechanism of human disease, since the epigenetic effect of an IM in the parental germ line determines the phenotypic effect in the patient.

Comparison of chromosome telomere integrity in multiple tissues from subjects at different ages

Telomere DNA, at the ends of each chromosome, is conserved in nature and required for chromosome replication and stability. Reduction in telomere length has been observed in several malignancies as well as in leukocytes from healthy persons with advancing age. There is a paucity of data regarding telomere length and the effects of in vivo aging in different tissues. These data could be helpful in interpreting telomere length and understanding the role of telomere integrity and telomerase activity in malignant cells. We report telomeric DNA integrity studies of blood and skin collected from eight Caucasians of both sexes representing each decade of life from the fetus to 72 years of age without exposure to chemotherapy or radiation. In addition, telomeric data from 15 other tissues from the fetus and 8 other tissues from the 72-year-old male were examined. No significant differences were found in the shortest telomere size, the average telomere size, or telomere size variation between blood and skin from subjects at different ages. The average telomere size was 11.7 +/- 2.2 kb for blood and 12.8 +/- 3.7 for skin in all subjects studied. The shortest telomere length was 5.4 +/- 1.9 kb for blood and 4.3 +/- 0.9 kb for skin. Significant differences (P < 0.001) were found in the overall length of the DNA hybridization signal representing the shortest telomere size and the length of the DNA peak migration hybridization signal representing variation in telomere size between the 20-week fetus and the 72-year-old male. The 72-year-old male showed the shortest telomeres and the most variation (heterogeneity) in telomere size for all tissues studied, but the greatest differences were observed in blood compared with other tissues (e.g., average telomere length was 12.2 kb in the fetus and 7.2 kb in the 72-year-old male). The size of the telomere was negatively correlated with age for all tissues studied.

Telomerase activity in skeletal sarcomas

BACKGROUND

Telomerase is a ribonucleoprotein that adds TTAGGG nucleotide repeats onto the ends of eukaryotic chromosomes to maintain telomere integrity. Somatic cells do not express telomerase and stop dividing when the chromosomal ends are shortened critically after many cell divisions. Immortal cell lines and cancer cells apparently have telomerase activity that contributes to an unlimited number of cell cycles. The purpose of our study is to investigate whether telomerase activity is expressed in primary malignant tumors of the skeletal system when compared to adjacent normal tissue.

METHODS

Fresh tumor and normal tissue was collected from 14 patients (10 males, 4 females; age range, 8 to 76 years) and protein extraction performed. The tumors included seven osteosarcomas (three examined before and after chemotherapy), two chondrosarcomas, two spindle cell tumors, one hemangiopericytoma, one chordoma, and one adamantinoma. Telomerase activity was analyzed by using a highly sensitive polymerase chain reaction (PCR)-based assay (telomere repeat amplification protocol [TRAP]).

RESULTS

Telomerase activity was found in 8 of 14 sarcoma patients (57%) using the TRAP assay. Compared to HeLa cell extract (positive control), telomerase activity in the tumor specimen ranged from 0 (in osteosarcoma) to 11.7% (in hemangiopericytoma). There was variation in the number of telomeric repeats generated by telomerase. At least five telomeric bands (e.g. 50, 56, 62, 68, 74 bp) in a ladder pattern had to be present before telomerase activity was considered positive in our analysis.

CONCLUSIONS

Telomerase activity may be an oncogenic sustaining event helping to maintain the transformed phenotype seen in malignant tumors of the bone. The degree of telomerase activity varies among skeletal malignancies, but was less than that observed in HeLa cells. The majority of osteosarcomas showed no telomerase activity.

Domain-directed polymerase chain reaction capable of distinguishing bacterial from host DNA at the single-cell level: characterization of a systematic method to investigate putative bacterial infection in idiopathic disease

The use of a broad-range PCR to target conserved sequences in the bacterial ribosome has long been recognized as an approach to investigating idiopathic human diseases for the presence of bacteria. An important example is rheumatoid arthritis where the hypothesis of a bacterial etiology remains viable despite failure of previous methods to identify a causative organism. Practical implementation of this strategy, however, was impeded by requirements unique to the study of these diseases. Hence, an adequately characterized method for achieving this has not appeared. We now describe such a method based on the use of a broadly reactive pair of deoxyinosine-containing primers. Detailed characterization addressing these requirements provided evidence that DNA from at least 96% of potential prokaryotic pathogens would be detected. The sensitivity was shown to approximate that of a single organism per reaction. Importantly, this sensitivity was shown to be maintained among multiple targets and to be unimpaired by a large excess of human DNA. Similar results were obtained with extracts of inflamed human synovial fluid to which as little as 0.01 pg of bacterial DNA or, alternately, a single organism per reaction was added. This method was also shown correctly to detect the causative bacteria in clinically infected synovial fluids, further documenting its applicability to such specimens. Finally, it was converted to an in situ method by which bacterial sequences were histochemically localized to Michaelis-Guttman bodies in tissue sections from a patient with malakoplakia, a poorly understood infectious disease. The broad reactivity and high sensitivity achieved by this approach translate into a high likelihood of detecting an unknown bacterium if present in a clinical specimen. Conversely, if properly controlled, the failure of this method to detect such organisms can provide evidence supporting rejection of the bacterial etiology hypothesis, an important aspect unique to this approach. For those bacterial sequences that are detected, the ability to localize them in situ would help define their histologic context and hence facilitate their pathogenetic interpretation. The present method should therefore be appropriate for use in systematically studying rheumatoid arthritis as well as a number of other important idiopathic disorders where a bacterial etiology is suspect.

Use of the polymerase chain reaction to study arthritis due to Neisseria gonorrhoeae

OBJECTIVE

To explore the utility of the polymerase chain reaction (PCR) in the diagnosis, management, and investigation of arthritis due to Neisseria gonorrhoeae.

METHODS

The PCR was used to detect DNA from N gonorrhoeae in model systems and in extracts of synovial fluid (SF) from patients with systemic gonococcal infections and objective evidence of arthritis.

RESULTS

One N gonorrhoeae organism or its equivalent was detectable in human SF from inflamed joints. Five of 8 patients with systemic N gonorrhoeae infection and arthritis had N gonorrhoeae DNA demonstrated by PCR in at least 1 pretreatment SF specimen that was N gonorrhoeae culture positive. Thirty-seven of 38 control specimens were negative, the exception probably being due to cross-contamination from a positive specimen. All specimens that were positive for N gonorrhoeae by other methods were also positive by PCR. Two others were positive by PCR but negative by other methods. Four pretreatment specimens were negative by all methods, including PCR. This suggests that, for these patients, negative cultures reflected true absence of N gonorrhoeae, and not the presence of unculturable organisms. This group also had a significantly shorter duration of disease than did the patients with N gonorrhoeae DNA found in their SF. All patients had a prompt response to antibiotic treatment. Two of 3 patients whose specimens were previously positive showed marked decreases in SF N gonorrhoeae DNA after treatment.

CONCLUSION

The PCR using these or similar oligonucleotide primers can be a useful adjunct in the diagnosis of gonococcal arthritis and can be of value in assessing its response to therapy. In some N gonorrhoeae-associated arthritides, there appears to be a lack of both viable and nonviable N gonorrhoeae organisms in the SF. These observations may have implications regarding the pathogenesis of this form of arthritis.

Design and characterization of PCR primers for detection of pathogenic Neisseriae

Oligonucleotide polymerase chain reaction (PCR) primers directed at a group of closely related Neisserial species were designed from 16S rDNA sequences even though only a single such sequence from the targeted group was known. The amplifiable group included all Neisserial species considered pathogenic for man, including Neisseria gonorrhoea and Neisseria meningitidis. None of 43 other bacterial DNA specimens were amplified, including five non-Neisserial Neisseriaceae and three non-pathogenic Neisseriae. Another non-pathogenic Neisserial species gave a signal only at high DNA concentrations. DNA specimens from the pathogenic Neisseriae were detectable in amounts as low as 0.01 pg per PCR reaction, the approximate equivalent of a single organism, with equal sensitivity in buffer or in simple extracts of human inflammatory synovial fluids to which Neisserial DNA had been added. Simultaneously studied control specimens lacking added DNA were negative. The approach used to design these group-directed primers using only a single rDNA sequence from the targeted group by exploiting known patterns of sequence conservation among the 16S rDNA genes may prove useful for designing other similar group-directed primers. Polymerase chain reaction primers prepared in this way should prove of value in a number of areas, both investigational and clinical.

Hierarchical gene diversity and genetic structure of tribal populations of Andhra Pradesh, India

Gene diversity and genetic structure of tribal populations of Andhra Pradesh, India, have been analyzed under a hierarchical model consisting of five regions of the state, tribes within the regions, and local subpopulations within the tribes. Average gene diversity has been estimated from gene frequency data for 15 polymorphic loci by using nested gene diversity analysis of GST. The intralocation coefficient of gene diversity was estimated at 96% of the total, whereas the intertribal, within--and between--regional gene diversities were found to be only 1.90, 0.95, and 1.43%, respectively. The estimate of gene diversity was higher for loci with higher degrees of polymorphism such as ABO, MN, ESD, and PTC and lower for loci with low-level polymorphism and extreme gene frequencies such as Hb, Tf, PHI, 6PGD, and Hp. The nature of selective preference or neutrality at the loci seems to be important in this respect. Tribes of the plains exhibit the least gene diversity, apparently because of higher gene flow among them. The contribution of loci with intermediate gene frequencies in intertribal and regional gene diversity was found to be higher than for loci with extreme allelic frequencies. These results suggest that the most significant component of variation is between individuals within locations and that variation between local subpopulations is negligible in the genetic structure of a population. Forces like selection, gene flow and drift also influence the diversity depending upon the nature of the locus.

Haemodialysis as a model for studying endogenous plasma DNA: oligonucleosome-like structure and clearance

The rate of clearance of extracellular plasma DNA in man has important implications for pathogenetic mechanisms in systemic lupus erythematosus (SLE), as well as for certain other clinical states. Present knowledge of this parameter is derived exclusively from studies of injected, naked DNA in animals. Recent information indicates that the physiologic form of plasma DNA in SLE is that of oligonucleosome-like molecules rather than of naked DNA and consists of multimeric complexes of DNA bound to histone, probably arising from an apoptotic process. In order to study the rate at which these oligonucleosome-like complexes are removed from plasma and to do so in man rather than experimental animals, we exploited the observation that during haemodialysis large amounts of DNA are released, apparently within the dialysis coil, into the patient's plasma. Since this release appears to cease promptly with termination of the procedure, it offered the potential for estimating the rate of removal of such DNA from human plasma. Moreover, if that DNA, as postulated, were shown to possess an oligonucleosome-like structure resembling that found endogenously in human SLE, the relevance of such information to the human disease state would be further enhanced. The present results support the conclusion that DNA released into plasma during haemodialysis possesses such an oligonucleosome-like structure. The plasma half-life of that DNA in man was found not to exceed 4 min. The highly dynamic state thus implied for extracellular endogenous plasma DNA in man has important implications for pathogenetic mechanisms dependent on dsDNA in SLE. Moreover, individuals undergoing chronic haemodialysis, who are thereby exposed to a very large cumulative amount of such DNA, might serve as models for studying its long-term sequelae.

Geometric differences allow differential enzymatic inactivation of PCR product and genomic targets

The value of the polymerase chain reaction (PCR) is markedly limited by the ease of carry-over contamination. We predicted that the location of the target sequence which spans the linear center of the molecule in PCR products, but not in genomic molecules, would allow digestion by certain exonucleases (Exo). This would eliminate amplifiable targets specifically from PCR products and do so without the need to control either the size of the genomic molecules or the extent of the digestion reaction. Testing with T7 Exo and model targets in phage lambda DNA yielded results consistent with those predicted. By heat inactivating the Exo, complete reaction mixtures could be decontaminated and then amplified in an automatic thermal cycler without reopening the reaction tubes and risking recontamination.

Invasion of the central nervous system by Borrelia burgdorferi in acute disseminated infection

OBJECTIVE

To determine central nervous system (CNS) involvement in acutely disseminated Borrelia burgdorferi infection by measurement of borrelia-specific DNA using the polymerase chain-reaction (PCR) assay and to compare the results of this with standard serological tests.

DESIGN

Prospective study with laboratory investigators blinded to clinical data.

SETTING

Multicenter office practice with a central reference laboratory.

PATIENTS

Cerebrospinal fluid (CSF) was collected from 12 patients with acute disseminated Lyme borreliosis with less than 2 weeks of active disease. The normal control specimens came from 16 patients whose CSF samples had been sent to the clinical laboratory for tests unrelated to the present study.

MAIN OUTCOME MEASURES

Clinical evidence of disease and laboratory abnormalities.

RESULTS

Eight of the 12 patients (four of six with multiple areas of erythema migrans and four of six with cranial neuritis without erythema migrans) had B burgdorferi-specific DNA in their CSF. Among the 12 patients studied, nine had acute cranial neuritis and six had multiple erythema migrans lesions. Just four of the eight who were found to have spirochetal DNA in their CSF had complaints suggestive of CNS infection. In three of the PCR-positive CSF samples, no other abnormalities were noted. None of 16 samples from controls were positive in the PCR assay.

CONCLUSION

B burgdorferi can invade the CNS early in the course of infection. Careful consideration should be given to choosing antibiotics that achieve adequate CSF levels in patients with disseminated infection.

Genetic structure of three Naikpod subpopulations of Andhra Pradesh, India

The genetic structure of three subpopulations of the Naikpod tribe of Andhra Pradesh, India, was examined by studying three blood group, six red cell enzyme, and five protein systems and phenylthiocarbamide taste sensitivity. The gene frequency data of 15 loci are compared among the subpopulations as well as with those reported for other population groups from India. The analysis of gene diversity revealed that the gene differentiation among the subpopulations relative to total population is only 0.02, indicating that the genetic differentiation between subpopulations is very small compared with that within them. This is corroborated by the small genetic distances found among them. The effect of differentiation of microgeographical and breeding isolation on gene diversity and genetic differentiation among the three subpopulations is apparently low.

Serological and biochemical genetic variation among three subpopulations of Naikpod tribe of Andhra Pradesh, India

A total of 353 blood specimens belonging to three subpopulations of Naikpod tribe of Andhra Pradesh, India, were tested for 12 serological and biochemical marker systems: ABO and Rh blood groups, ESD, SOD1, LDH, MDH1 red cell enzymes, HB and TF, HP, CP, ALB plasma proteins. The results were compared among the three groups by chi-square analysis and they revealed no significant differences among them with the exception of TF system. In addition an attempt was made to compare the observed gene frequencies with those reported for other populations from the Indian subcontinent.