Academic literature on the topic 'Gene polymorphism'

SummaryLipoprotein (a) [Lp(a)] is a quantitative genetic trait in human plasma and elevated levels represent a major inherited risk factor for the development of atherosclerotic disease. In our search for sequence polymorphisms in the coding region of the apolipoprotein(a) [apo(a)] gene that may affect the Lp(a) concentration, four new polymorphic sites were identified. These include two coinciding polymorphisms with an allele frequency of 38% located at amino acid positions 87 and 101 (Leu87,101 →Val) in the interkringle region of kringle IV (K.IV) type 7 and two polymorphisms located in K.IV type 7 (Arg60 →Ser) and in K.IV type 10 (Tyr2 →Phe) both with estimated allele frequencies of about 1%.The linkage between the newly identified K.IV type 7 Leu87,101 →Val polymorphism and earlier described polymorphic sites in the non-coding and coding regions of the apo(a) gene, its distribution over the apo(a) isoform sizes and its possible influence on the Lp(a) concentration was analysed in 201 healthy unrelated Caucasians. The earlier described polymorphic sites included in this study were the variable number of a TTTTA pentanucleotide repeat (7-11 PNR) starting at -1231 bp, the -772 bp G/A polymorphism, the +93 bp C/T polymorphism and the +121 bp G/A polymorphism in the non-coding region, and the K.IV type 8 Thr12/Pro polymorphism and the K.IV type 10 Thr66/Met polymorphism in the coding region of the apo(a) gene.Linkage disequilibria were observed between the polymorphic sites in the 5’ non-coding region and the sites in K.IV type 7 and 8 in the coding region of the apo(a) gene, confirming that the expansion of the variable number of K.IV type 2 repeats results from intrachromosomal recombinational events. The distribution over the apo(a) isoform sizes of the K.IV type 7 Val87,101 subtype was not significantly different from that of the K.IV type 7 Leu87,101 wild-type, suggesting a relative ancient mutational event. No influence of the K.IV type 7 Leu87,101 →Val polymorphism on the Lp(a) level was observed. In fact, of all the polymorphic sites studied, only the +121 A subtype could be associated with an increased, and the K.IV type 8 Pro12 and the 10 PNR subtypes with a reduced, Lp(a) concentration corrected for apo(a) isoform size (p <0.05).

Polymorphisms of the progesterone receptor gene alter the expressions of two receptor isoforms involved in the regulation of progesterone's antiproliferative effect in endometriotic tissue. This study aims to identify the +331G/A polymorphism of the progesterone receptor gene in endometriosis patients in Palembang, South Sumatra. Identification of +331G/A single-nucleotide polymorphism (SNP) was conducted on 42 endometriosis patients through polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP). In this study, twenty-six (61.9%) subjects had heterozygous mutant genotype for the +331G/A SNP. No subject with homozygous mutant genotype for the +331G/A polymorphism was identified. The frequencies of polymorphic alleles for the +331G/A polymorphism was 30.9%. In conclusion, the +331G/A progesterone receptor gene polymorphism was present in endometriosis patients in Palembang, South Sumatra. This finding may warrant further studies to determine whether this polymorphism play a role in the development of endometriosis in the Indonesian population.

Purpose: To investigate vitamin D receptor polymorphisms in ocular surface squamous cell neoplasm and to evaluate the relationship between the identified polymorphisms and susceptibility to ocular surface squamous cell neoplasm and the clinical course. Materials and Methods: A totala of 70 patients with ocular surface squamous cell neoplasm (study group) and 75 healthy age and gender-matched individuals (control group) were included in the study. Vitamin D receptor FokI and BsmI polymorphisms were examined. The relationships between histopathological diagnosis, recurrence rates, tumor stage, and identified polymorphisms were investigated. Results: Histopathologically, 43 of the cases were squamous cell carcinoma and 27 of the cases were conjunctival intraepithelial neoplasia. The frequency of FokI (FF, Ff, ff) and BsmI (BB, Bb, bb) polymorphism genotype of vitamin D receptor gene were similar in the groups. The frequency of polymorphism (heterozygous or homozygous) for BsmI (Bb and bb) was significantly higher (p = 0.046) in the study group, while no difference was found between the groups in terms of polymorphic carriers (heterozygous or homozygous) for FokI. There was no correlation between tumor stage, recurrence-polymorphism frequency, and patient age-polymorphism frequency. Conclusion: It is known that active vitamin D inhibits the growth of cancer cells by binding to vitamin D receptor with regulation of genes responsible for cell proliferation. The presence of BsmI polymorphism in vitamin D receptor, in particular bb genotype and b allele, appears to be associated with the susceptibility of ocular surface squamous cell neoplasm. BsmI gene polymorphisms of vitamin D receptor might play an effective role in the formation, progression, and in the course of ocular surface squamous cell neoplasm.

Aim: to investigate the role of polymorphic variants of immune-response modifying genes in predisposition to asthma. Patients and methods. The analysis of restriction fragments length polymorphism was used to investigate 10 single-nucleotide polymorphisms: IFNG rs2069705, IFNGR2 rs17880053, IL4 rs 2070874, IL4RA rs 1805010, GATA3 rs10905277, TBX21 rs11652969, PIASY rs3760903, PIAS3 rs12756687, STAT5β rs16967593, and SOCS5 rs6737848 in 106 asthma patients and 115 healthy people. Results. The rs6737848 SOCS5 polymorphism was significantly associated with asthma in additive model (р =0,05, OR =0,338, 95%CI 0,158–0,723) and in dominant model (р =0,02, OR =0,284, CI 0,126–0,638). None of the polymorphisms of the studied genes was associated with total IgE levels. Conclusions. This is the first report on the association of rs6737848 SOCS5 with asthma.