HindIII Restriction Fragment Length Polymorphism Research Articles

Analysis of complement receptor Type 1 expression on red blood cells in negative phenotypes of the Knops blood group system, according to CR1 gene allotype polymorphisms

The KN blood group system, which consists of nine antigen specificities, is located on complement receptor Type 1 (CR1/CD35). CR1, a complement regulatory protein, acts as a vehicle for immune complex clearance. CR1 exhibits a red blood cell (RBC) density polymorphism. CR1 sites on RBCs in normal individuals range from 150 to 1200 molecules per cell. CR1 density polymorphism is regulated by HindIII restriction fragment length polymorphism and Q981H and P1786R polymorphisms in Caucasians. Yet, the role of the different polymorphisms in determining the CR1 density on RBCs remains unknown. The "null" serologic KN phenotype, known as Helgeson phenotype, was reported to be related with a very low CR1 density, less than 150 molecules per cell. The aim of this work was to investigate whether the KN-negative phenotype displayed by 60 individuals was related to the CR1 density by performing the phenotypic and genetic analysis of CR1 and to investigate the molecular background associated with the KN system. We showed that the Helgeson-like phenotype had a prevalence of 12% in this population. The overall genotype/phenotype concordance was 90%. Among individuals with a KN-negative phenotype, the prevalences of Kn(a-), McC(a-), Sl1-negative, Sl3-negative, and KCAM-negative deduced phenotype were 37, 12, 29, 7, and 24%, respectively. From our data, we suggest that the definition of the Helgeson phenotype must be revised, since the latter may be due not only to a very low CR1 density on RBCs, but also to the absence of expression of a high-prevalence KN antigen.

Leuconostoc Spoilage of Vacuum-Packaged Vegetable Sausages

The present study was conducted to assess the role of lactic acid bacteria (LAB) in spoilage of a vacuum-packaged vegetable sausage product. This spoilage problem was characterized by formation of gas and slime, and was limiting the shelf life of the product. To investigate the LAB populations, LAB were enumerated in vegetable sausages graded as either spoiled or acceptable. From these vegetable sausages, 110 prevailing LAB isolates were recovered and identified using an LAB ribotyping database, which uses HindIII restriction fragment length polymorphism patterns of the 16S and 23S rRNA genes as operational taxonomic units. Finally, to determine the effects of the prevailing LAB on the sensory properties of the product, fresh vegetable sausages were inoculated with six LAB strains. The results revealed that Leuconostoc gelidum, Leuconostoc gasicomitatum, and Leuconostoc mesenteroides were the predominant LAB in the commercial vegetable sausages. The inoculation of these LAB onto vegetable sausages resulted in the formation of gas, slime, and a sour off-odor. Based on these findings, L. gelidum, L. gasicomitatum, and L. mesenteroides were responsible for spoilage of the vegetable sausage product.

Association of the Lipoprotein Lipase Gene T+495G Polymorphism With Central Obesity and Serum Lipids in a Twin Study

The lipoprotein lipase (LPL) gene polymorphism is possibly involved in the pathophysiology of central obesity and dyslipidemia. The aim of this study was to investigate the association of LPL gene T+495G polymorphism with central obesity and serum lipids. A total of 961 adult twin pairs were enrolled from the program of Chinese Twin Registry, between 2001 and 2002. We used 90 cm of waist circumference in male and 80 cm in female as cut-off values of central obesity. The LPL gene T+495G polymorphism was analyzed with the use of genomic polymerase chain reaction and HindIII-restriction fragment length polymorphism. Two statistical methods were performed to test the effect of T+495G polymorphism of LPL gene on the relation between central obesity and lipid levels: one was the generalized estimating equation model for all twin pairs and the other was co-twin matched case-control analysis in 82 central obesity discordant monozygotic twin pairs. In male twins, central obesity was significantly associated with serum lipids except for high-density lipoprotein (HDL). In female twins, obesity twins had significantly higher levels of triglyceride (TG) and TG/HDL than nonobesity twins. There was no significant association between T+495G polymorphism and lipid levels for all twins, although +495G allele carrier was related with 6.7% decrease of TG was observed only in female twins. The interactions of T+495G polymorphism and central obesity were not found for TG, HDL, and TG/HDL. In central obesity discordant monozygotic twin pairs, central obesity was significantly related with 24.2%, 26.1%, and 4.1% increase of TG ,TG/HDL, and TC, respectively, in +495T/T genotype. These results suggest no association and interaction of T+495G polymorphism with central obesity and serum lipids for all twin pairs. Meanwhile, a modest genetic-environmental effect of T+495G polymorphism and central obesity was found in discordant monozygotic twin pairs. Therefore, the +495T/T genotype may be an independent risk factor associated with central obesity and lipids level. However, the role of LPL gene T+195G polymorphism in central obesity and dyslipidemia is complex and remains controversial. This hypothesis needs further investigation.

Lactic Acid Bacteria in Marinades Used for Modified Atmosphere Packaged Broiler Chicken Meat Products

Lactic acid bacteria (LAB) in some marinades commonly used in Finland for modified atmosphere packaged poultry meat products were enumerated and identified to determine whether the marinades contained LAB species that cause meat spoilage. The concentrations of LAB in 51 marinade samples ranged from less than 100 to 8.0 × 105 CFU/ml. Seventeen of the samples produced LAB growth only after enrichment, and in five samples no growth was detected either by direct culturing or enrichment. Eighty-eight randomly selected isolates, 51 from the enumerated plates and 37 from enriched samples, were identified using a database of 16S and 23S rRNA gene HindIII restriction fragment length polymorphism patterns of over 300 type and references LAB strains as operational taxonomic units in numerical analyses. The predominating LAB in the enumerated samples was Lactobacillus plantarum (25 of 51 isolates). Eleven isolates were identified as Lactobacillus paracasei subsp. paracasei, and nine were Lactobacillus parabuchneri. None of these species are considered specific spoilage LAB in marinated modified atmosphere packaged poultry meat products nor have they been reported to dominate in unspoiled late-shelf-life products. These results indicate that even though marinades may contain high numbers of LAB, they are not necessarily sources of specific meat spoilage LAB. Therefore, risks associated with meat quality are not predicted by quantitative enumeration of LAB in marinades.

Association of gene polymorphisms for plasminogen activators with alveolar bone loss

The plasminogen activating system is a protease/inhibitor system central to extracellular matrix remodeling with a suggested role in periodontal disease pathology. A few studies have reported polymorphisms in the genes of plasminogen activator inhibitors to be associated with periodontal disease severity. Two gene polymorphisms - a BamHI restriction fragment length polymorphism in the urokinase plasminogen activator gene (uPA) and a HindIII restriction fragment length polymorphism in the plasminogen activator inhibitor type 1 gene (PAI-1) - have been associated with conditions having a vascular component, and our objective was to assess the association of these gene polymorphisms with alveolar bone loss in chronic periodontal disease of adults. Genotype was determined by polymerase chain reaction amplification of whole blood, pertinent histories were obtained by interview, and alveolar bone loss was assessed from current radiographs. In 77 elderly patients with a normal distribution of alveolar bone loss, we demonstrated a significant association between levels of alveolar bone loss and these polymorphisms in the uPA and PAI-1 genes. Controlling for the contributions of smoking or diabetes to periodontal bone loss, estimated odds ratios for predicting lower levels of alveolar bone loss, associated with a greater degree of periodontal health, were strongest when defined by the concurrent presence of a homozygous urokinase plasminogen activator genotype and the nuclease-sensitive plasminogen activator inhibitor type 1 (HindIII) allele (odds ratio = 2.6; 95% confidence interval: 5.8-1.3). The urokinase plasminogen activator (BamHI) and plasminogen activator inhibitor type 1 (HindIII) genotypes may serve as useful markers for heritability of bone loss associated with periodontal disease.

Association of HindⅢ RFLP in lipoprotein lipase gene with type 2 diabetes

We examined the association of a Hind RFLP (restriction fragment length polymorphism) in the lipoprotein lipase (LPL) gene with type 2 diabetes (T2DM) in Chinese Han population in Hubei Province. Genotypes were determined by PCR-RFLP in 102 controls and 264 T2DM patients using sib-pair and unrelated case-control designs. The frequencies of the H+ allele and H+H+ genotype for patients were significantly higher than those for controls (H+: 76.9% vs 69.1%, P < 0.05; H+H+: 59.8% vs 52%, P < 0.05). When all subjects were grouped as designed, the H+ allele and H+H+ genotype for sib patients were significantly higher than those for sib controls (H+: 81.5% vs 67.8%, P < 0.05; H+H+: 68.5% vs 50.7%, P < 0.05), while there were no significant differences in controls and random patients (P>0.05). Logistic regression analysis suggested that risk factors for T2DM was fasting plasma glucose and LPL genotypes, with individuals with the H+H+ genotype doubling their risk for T2DM as compared to those with the H+H- and H-H- genotypes (95% CI: 1.0363.840, P < 0.05). These data suggest that the Hind RFLP in the LPL gene is associated with T2DM risk in Chinese Han population in Hubei Province, and the H+ allele may serve as a genetic risk factor of T2DM.

Role of broiler carcasses and processing plant air in contamination of modified-atmosphere-packaged broiler products with psychrotrophic lactic acid bacteria.

Some psychrotrophic lactic acid bacteria (LAB) are specific meat spoilage organisms in modified-atmosphere-packaged (MAP), cold-stored meat products. To determine if incoming broilers or the production plant environment is a source of spoilage LAB, a total of 86, 122, and 447 LAB isolates from broiler carcasses, production plant air, and MAP broiler products, respectively, were characterized using a library of HindIII restriction fragment length polymorphism (RFLP) patterns of the 16 and 23S rRNA genes as operational taxonomic units in numerical analyses. Six hundred thirteen LAB isolates from the total of 655 clustered in 29 groups considered to be species specific. Sixty-four percent of product isolates clustered either with Carnobacterium divergens or with Carnobacterium maltaromaticum type strains. The third major product-associated cluster (17% of isolates) was formed by unknown LAB. Representative strains from these three clusters were analyzed for the phylogeny of their 16S rRNA genes. This analysis verified that the two largest RFLP clusters consisted of carnobacteria and showed that the unknown LAB group consisted of Lactococcus spp. No product-associated LAB were detected in broiler carcasses sampled at the beginning of slaughter, whereas carnobacteria and lactococci, along with some other specific meat spoilage LAB, were recovered from processing plant air at many sites. This study reveals that incoming broiler chickens are not major sources of psychrotrophic spoilage LAB, whereas the detection of these organisms from the air of the processing environment highlights the role of processing facilities as sources of LAB contamination.

Leuconostoc carnosum Associated with Spoilage of Refrigerated Whole Cooked Hams in Greece

A polyphasic taxonomic approach was used to identify a major atypical group of gas-forming, arginine-negative lactic acid bacteria associated with spoilage of whole (nonsliced) refrigerated (4°C) cooked hams produced in two Greek industrial meat plants. Biochemical characterization revealed that the ham isolates shared their phenotypic properties with Leuconostoc carnosum, Weissella viridescens, and Weissella hellenica. However, gas chromatographic analysis of cellular fatty acids clearly differentiated the ham isolates from the Weissella spp. None of the isolates contained eicosenoic acid (n-C20:1), which is typically synthesized by W. viridescens, but all strains contained high amounts of C19cycl acid, which is absent in W. hellenica and has been found in trace amounts in W. viridescens. All strains had similar cellular fatty acid profiles, which were qualitatively similar to those of the cellular fatty acids of L. carnosum. In addition to the phenotypic and chemotaxonomic tests, three representative isolates were studied using a lactic acid bacteria database, which employs 16S and 23S HindIII restriction fragment length polymorphism patterns as operational taxonomic units in a numerical analysis. The isolate patterns were identical to those of the L. carnosum type strain, NCFB 2776T. Based on the polyphasic taxonomic approach, the dominating lactic acid bacteria group was identified as L. carnosum.

Erythrocyte complement receptor 1 (CR1) expression level is not associated with polymorphisms in the promoter or 3′ untranslated regions of the CR1 gene

Complement receptor 1 (CR1) expression level on erythrocytes is genetically determined and is associated with high (H) and low (L) expression alleles identified by a HindIII restriction fragment-length polymorphism (RFLP) in intron 27 of the CR1 gene. The L allele confers protection against severe malaria in Papua New Guinea, probably because erythrocytes with low CR1 expression, are less able to form pathogenic rosettes with Plasmodium falciparum-infected erythrocytes. Despite the biological importance of erythrocyte CR1, the genetic mutation controlling CR1 expression level remains unknown. We investigated the possibility that mutations in the upstream or 3' untranslated regions of the CR1 gene could control erythrocyte CR1 level. We identified several novel polymorphisms; however, the mutations did not segregate with erythrocyte CR1 expression level or the H and L alleles. Therefore, high and low erythrocyte CR1 levels cannot be explained by polymorphisms in transcriptional control elements in the upstream or 3' untranslated regions of the CR1 gene.

Low Erythrocyte Complement Receptor Type 1 (CR1, CD35) Expression in Preeclamptic Gestations

Erythrocyte complement receptor type 1 (E-CR1) is the main immune complex clearance mechanism in humans. Decreased E-CR1 expression is noted in certain inflammatory disorders. Recent evidence implicates inflammation in the pathogenesis of preeclampsia. We investigated whether E-CR1 is decreased in preeclampsia. E-CR1 protein expression was quantified by radioimmunoassay. Plasma concentration of soluble CR1 was quantified using a specific enzyme linked immunosorbent assay. Quantitative genotypes were evaluated by HindIII restriction fragment length polymorphism analysis. E-CR1 expression was reduced in patients with preeclampsia. Lack of neoantigen expression (indicative of enzymatic cleavage of CR1) or elevated plasma-soluble CR1 was evidence against an acquired loss of E-CR1. Genotype analysis revealed a higher frequency of a CR1 allele associated with low E-CR1 expression in preeclampsia when compared with normal pregnant controls. E-CR1 expression is decreased in preeclamptic patients and levels correlate with severity of disease. This condition may have a genetic basis in some patients.

Duplex PCR-RFLP for simultaneous detection of factor V Leiden and prothrombin G20210A

The authors have used a primer-engineered duplex polymerase chain reaction (PCR) -restriction fragment length polymorphism (RFLP) for the simultaneous detection of factor V Leiden and prothrombin G20210A mutations. The method involves the generation of HindIII RFLPs, and the restricted amplification products are analyzed by agarose gel electrophoresis in a single gel lane. This method is simple an inexpensive, and readily adaptable to the routine in a clinical molecular diagnostic laboratory other that our own.

Genetics of the lipoprotein lipase gene and hypertriglyceridaemia

The aim of this study is to assess whether genetic variation at the lipoprotein lipase (LPL) gene is related to fasting triglyceride levels or to the presence of vascular disease. Hypertriglyceridaemic patients are genotyped for the N291S, G188E, and P207L variants and the HindIII and PvuII restriction fragment length polymorphisms of the LPL gene. Sequence analysis is carried out on exons 1–9 of the LPL gene for patients with severe hypertriglyceridaemia, to search for new gene variants. No differences were found between the patient and control group for the N291S, G188E and P207L variants. The HindIII and PvuII allelic frequencies were found to be similar for patients and controls; however, the frequency of the PvuII P2 allele was higher in patients with vascular disease (allele frequency: 0.56) than patients with no vascular disease (allele frequency, 0.42) (P=0.03). Sequence analysis revealed no exon sequence variants in the LPL gene but two intron sequence variants were found in intron 5 in two patients.

Erythrocyte CR1 expression level does not correlate with a HindIII restriction fragment length polymorphism in Africans; implications for studies on malaria susceptibility.

Complement receptor 1 (CR1) expression level on erythrocytes is genetically determined, and in Caucasian populations is linked to high (H) and low (L) expression alleles identified by a HindIII restriction fragment length polymorphism (RFLP). Erythrocyte CR1 may be an important factor in determining malaria susceptibility, as low expression of CR1 reduces the rosetting of uninfected erythrocytes with Plasmodium falciparum-infected cells, a process that contributes to malaria pathogenesis. Prior to studying CR1 expression and malaria susceptibility, we have investigated whether the quantity of erythrocyte CR1 correlates with the H and L alleles in an African population. Mean erythrocyte CR1 in 149 Malian adults was 415 molecules per cell, which is comparable to Caucasian populations; however, there was no relationship between erythrocyte CR1 level and genotype for the HindIII RFLP (mean CR1 per erythrocyte HH = 414, HL = 419 and LL = 403, P > 0.1, Student's t-test). The conclusions of a previous study of erythrocyte CR1 expression level and malaria susceptibility in West Africa that was based on HindIII RFLP genotyping may therefore need to be re-evaluated.

Factor VIII gene polymorphisms in North Indian population: a consensus algorithm for carrier analysis of hemophilia A

Background: Hemophilia A, an X-linked recessive disorder, has the prevalence of 1 male per 7000 of the male population in the Northern states of India. The aim of the present study was to analyze the polymorphisms of the factor VIII gene in a sample population comprised of 22 families (112 persons) in order to formulate an algorithm that would be informative and accurate, yet cost-effective for carrier diagnosis. Methods: Polymerase chain reaction was used to study the polymorphisms of two intragenic restriction fragment length polymorphic sites (recognized by BclI and HindIII) and an extragenic variable number tandem repeat (VNTR) locus (St14). Results: Fifty-eight percent of the women tested were heterozygous for the BclI restriction fragment length polymorphism (RFLP) (significantly high compared to earlier reports), signifying the usefulness of this marker in carrier detection. About 64% of the families from the target population could be diagnosed using this marker alone. The other intragenic HindIII RFLP site showed a heterozygosity rate of 43% in women, and was effective in diagnosing 50% of the families studied. The population prevalence for ‘+’ alleles of BclI and HindIII were 68% and 33%, respectively. About 88% of the women tested were heterozygous for the St14 locus, and 83% of the families could be diagnosed using this marker alone. The 1390- and 1300-bp alleles were most prevalent, while novel polymorphisms of 1500 and 1345 bp were detected. Conclusions: Based on the above data, we suggest screening hemophilic families first for BclI polymorphism, followed by an analysis for HindIII polymorphism in case of homozygosity at the BclI site. When both were noninformative, analysis of St14 locus would be necessary.

Suitability of four polymorphic DNA markers for indirect genetic diagnosis of haemophilia A in Japanese subject

Indirect genetic diagnosis using polymorphic DNA markers can detect carriers of haemophilia A (HA). These markers include CA repeat polymorphisms at intron 13 (CA-13) and CT-AG at intron 22 of the coagulation factor VIII (FVIII) gene, and also certain restriction fragment length polymorphisms (RFLPs) such as HindIII at intron 19 and BclI at intron 18. Recently, CA repeat polymorphism at intron 6 (CA-6) was also reported. We compared usefulness of the BclI RFLP, the HindIII RFLP, and CA-13 to that of CA-6. Heterozygosity of markers was examined in 282 X chromosomes obtained from 205 subjects including HA patients. Expected heterozygosity of the HindIII and BclI RFLPs was 30.0% and 27.9%, while observed heterozygosity was 28.0% and 26.5%. Expected heterozygosity of CA-13 was 45.6%, and observed heterozygosity was 40.0%. CA-6 showed two alleles with repeat numbers of 13 and 14, expected and observed heterozygosity were low (1.4% and 2.6%, respectively). When we used these markers in a HA lineage where the mother was a carrier according to coagulation factor assays, carrier diagnosis was possible using CA-13, the HindIII RFLP, and the BclI RFLP. This was not true for CA-6, for which the mother was homozygous. Although CA-13, and the HindIII and BclI RFLPs were useful for indirect genetic diagnosis of HA, CA-6 proved less useful because of low heterozygosity.

FlaB-polymerase chain reaction (flaB-PCR) and its restriction fragment length polymorphism (RFLP) analysis are an efficient tool for detection and identification of Leptospira spp.

For establishment of a rapid-identification method of Leptospira species, a flaB gene of Leptospira was investigated and the following results were obtained. 1) HaeIII- or HindIII-restriction fragment length polymorphism (RFLP) of polymerase chain reaction (PCR) products (793 bp) of flaB gene was effectual for the classification of species of Leptospira. 2) Twenty cells of Leptospira in 1 ml of coagulated blood and 100 cells of Leptospira in 1 ml of anti-coagulated blood could be detected by flaB-PCR. These results suggested that PCR-RFLP based on the flaB gene was an efficient tool for rapid detection and identification of species of infected Leptospira from clinical specimens.

Genetic diversity of Bacillus thuringiensis serovars revealed by RFLP using random DNA probes.

EcoRI and HindIII restriction fragment length polymorphism (RFLP) profiles using 2 random DNA probes, named 104 and 106, were generated for 85 B. thuringiensis strains. These include 80 serovars, 4 intra-serovar strains: kurstaki HD-1, dendrolimus, tenebrionis and sandiego, and a non-serotypeable strain B. thuringiensis var. wuhanensis. A total of 47 EcoRI and 65 HindIII restriction patterns were generated when hybridization results from both probes were combined. Seventy-seven B. thuringiensis strains showed distinctive hybridization profiles. The dendrogram resulting from the numerical analysis of the distance matrix revealed fourteen distinct phylogenetic groups at the 96% banding patterns similarity. The intra-serovar strains showed higher similarity with their respective type serovars. However, different serovars from a common H-serotype did not always cluster in the same phylogenetic group. Alternatively, several mosquitocidal serovars clustered in a single phylogenetic group. The correlation between serotyping and banding pattern similarity is discussed.

Relation of polymorphism in the promotor region for the human osteocalcin gene to bone mineral density and occurrence of osteoporosis in postmenopausal Chinese women in Taiwan.

Osteoporosis is a common disorder with a strong genetic component. Our aim was to evaluate the correlation of the HindIII osteocalcin gene polymorphism to bone mineral density (BMD) and their relationship to osteoporosis. We determined the HindIII osteocalcin gene polymorphism using polymerase chain reaction (PCR)-based restriction analysis in postmenopausal Chinese women in Taiwan. The osteocalcin gene polymorphism was detected by the restriction enzyme HindIII, where the H allele indicated the absence of the cuttable site and the h allele indicated its presence. We then related the genotypes to BMD and occurrence of osteoporosis in these women. The allelic frequencies for postmenopausal Chinese women in Taiwan were 64% for h and 36% for H in HindIII restriction fragment length polymorphisms. The prevalence of each genotype in the study population was 37.7% hh, 52.6% Hh, and 9.7% HH. The subjects with genotype hh had the greatest BMD at the lumbar spine and the femoral neck, and those with HH had the smallest BMD at the femoral neck, but these differences did not reach statistical significance. The HindIII osteocalcin genotype showed a significant effect on the prevalence of osteoporosis in the subjects at the femoral neck, that is, women with genotype HH had a 6.4 times greater risk for osteoporosis (P < 0.05), and those with genotype Hh had a 1.2 times greater risk than women with genotype hh. In conclusion, the HindIII osteocalcin gene polymorphism is associated with reduced BMD and predisposes women to osteoporosis at the femoral neck.

Factor VIII gene polymorphisms in the Asian Indian population.

Little is known about the heterozygous frequency of factor VIII gene markers in the Asian Indian population. The objective of this study was to establish the heterozygous frequency of polymorphic markers within and flanking the factor VIII gene in Indians and identify those most informative for carrier screening and prenatal diagnosis. Factor VIII gene polymorphism analysis at intragenic and extragenic sites was carried out by the polymerase chain reaction (PCR) method and Southern blot procedure. Sixty-three Asian Indian haemophiliacs and their families were screened. A control group of 150 women from nonhaemophilic families were screened for two markers, HindIII and BclI. Among the intragenic markers studied, the HindIII restriction fragment length polymorphism (RFLP) showed the highest heterozygous frequency (0.52) followed by the intron 13 (0.47) and intron 22 (0. 44) short tandem repeats (STRs). Among extragenic markers, TaqI had the highest heterozygous frequency (0.75) followed by BglII (0.54). The intron 22 inversion mutation was observed in eight (40%) of 20 severe cases. In the population studied the most diagnostic polymorphisms were the intragenic markers, intron 22 (70%) STR followed by the intron 13 (52%) STR and HindIII (52%) RFLP, and the TaqI (50%) extragenic marker. Application of HindIII, BclI and the intron 22 dinucleotide repeat combined were diagnostic in 87.2% of haemophilia A families studied.

Lipoprotein lipase gene polymorphism, cholesterol subfractions and myocardial infarction in large samples of the general population

Genetic variants of the lipoprotein lipase gene have been associated with dyslipidemia and coronary artery disease. However, data have been inconsistent and are mainly based on selected predominantly male patient groups. We evaluated the influence of the HindIII restriction fragment length polymorphism on lipid levels in the general population (1361 participants of a large population-based survey from Augsburg, Germany; 50% women) as well as the association of this polymorphism with the risk of myocardial infarction (MI; genotype frequencies in 1159 patients with documented MI under 60 years of age). In the population-based survey, a highly significant association between the frequent H2H2 genotype and unfavorable cholesterol subfraction levels was observed in men and in postmenopausal women whereas no significant association was observed in premenopausal women (uni- and multivariate analysis). Such unfavorable lipid levels in homozygotes for the H2 allele may be expected to be associated with a 19-25% increased risk to suffer from myocardial infarction (MI). Nevertheless, genotype and allele frequencies in the general population were not different from those in patients with previous MI (H2H2 genotype frequency 51.3% vs. 53.2%, respectively; P=0.63). This large study shows that the H2H2 genotype of the lipoprotein lipase gene polymorphism is associated with unfavorable lipid levels. Estrogen status may modulate this association in women. The effects of the genotype on lipid levels were apparently not strong enough to reveal a significant association with MI.