Yazan: admin Tarih: Åžub 25th, 2010 | Kategori::
Paraoxonase
Turk Kardiyol Dern Ars. 2009 Oct;37(7):473-8.
Taşkiran P, Cam SF, Sekuri C, Tüzün N, Alioğlu E, Altintaş N, Berdeli A.
Department of Medical Biology and Genetics, Medicine Faculty of Celal Bayar University, Manisa, Turkey.
OBJECTIVES: Paraoxonase (PON1) is a high-density lipoprotein (HDL)-associated esterase that hydrolyses lipoperoxides. PON1 serves as a protective factor against oxidative modification of LDL, suggesting that it may play an important role in the prevention of atherosclerotic process. Research has focused on two polymorphisms: leucine (L allele) to methionine (M allele) substitution at codon 55, and glutamine (A allele) to arginine (B allele) substitution at codon 192. STUDY DESIGN: We examined amino acid changes at codon 55 and 192 in the PON1 gene by polymerase chain reaction and using restriction enzymes in 120 patients (92 men, 28 women; mean age 48.2+/-4.3 years) with premature coronary artery disease (CAD) and in 102 healthy subjects (80 men, 22 women; mean age 46.8+/-5.2 years) with no history of CAD and a normal electrocardiogram. RESULTS: Distribution of genotypes in the patient and control groups at codon 55 were 6.7% and 4.9% for MM, 46.7% and 29.4% for LM, 46.7% and 65.7% for LL, respectively. The frequency of genotypes at codon 192 were as follows: 4.2% and 2% for RR, 40% and 35.3% for QR, and 55.8% and 62.8% for QQ, respectively. While the frequency of PON1 55M allele was higher in the CAD group (0.3 vs. 0.2), PON1 192R allele frequency did not differ (p>0.05). There was a significant relationship between the PON1 M/L55 polymorphism and CAD (p=0.017), whereas the R/Q192 polymorphism was not associated with CAD (p=0.445). CONCLUSION: These data suggest that the PON1 M/L55 polymorphism shows a significant relationship with CAD and the Q/R192 polymorphism is not a major risk factor causing susceptibility to CAD in our population.
Yazan: admin Tarih: Åžub 5th, 2010 | Kategori::
Methylenetetrahydropholate Reductase
Turk Neurosurg. 2010 Jan;20(1):9-15.
Eser B, Cosar M, Eser O, Erdogan MO, Aslan A, Yildiz H, Boyaci G, Buyukbas S, Solak M.
Selcuk University, Meram Faculty of Medicine, Department of Medical Genetics, Konya, Turkey.
AIM: This study aimed to investigate the 677C > T and 1298A > C MTHFR gene polymorphisms and their metabolic effects on the levels of folate, vitamin B12 and homocysteine in the serum of Turkish spina bifida occulta (SBO) patients and healthy individuals in disease. MATERIAL and METHODS: A case-control study was performed to detect 677C > T and 1298A > C MTHFR gene polymorphisms in 39 SBO patients and 34 healthy individuals. The folate, vitamin B12 and homocysteine concentrations in the serum of SBO and healthy individuals were evaluated and compared with MTHFR gene polymorphisms. RESULTS: 677 CC/CT/TT MTHFR genotype frequency differences between the SBO patients and controls were not significant (x(2)=3.325, P=0.068; x(2)=1.479, P=0.224; x(2)=0.275, P=0.600; respectively). 1298A > C MTHFR genotype frequency differences between the SBO patients and controls were significant (x(2)=8.477, P=0.004). The frequencies of the Aand C alleles of the 1298A > C polymorphism did not differ in a statistically significant manner between the groups (x(2)=0.576, P=0.448). The biochemical parameters were not significantly different between SBO patients and healthy individuals (P > 0.05). CONCLUSION: The 677C > T and 1298A > C polymorphisms of the MTHFR gene cannot be regarded as major risk factors for SBO in the Turkish patients 677TT homozygosity may affect the metabolism of homocysteine.
Exp Biol Med (Maywood). 2009 Jun 22.
Konac E, Dogan I, Onen IH, Yurdakul AS, Ozturk C, Varol A, Ekmekci A.
Gazi University, Faculty of Medicine.
Hypoxia-inducible factor-1 (HIF-1), an important genetic component of angiogenesis, becomes stable as a response to tumor hypoxia and facilitates tumor survival. The polymorphisms of the HIF-1alpha gene may cause changes in the activity of the protein which serves as a transcription factor for many genes in tumorigenesis. In this study, we have investigated the relationship between seven HIF-1alpha polymorphisms [C>T substitution in intron 8 (rs10873142), T418I (rs41508050) in exon 10, P564P (rs41492849), L580L (rs34005929), P582S (rs11549465), A588T (rs11549467) in exon 12 and dinucleotide GT repeat in intron 13 (rs10645014)] among lung cancer patients in the Turkish population. Genomic DNA was isolated from 141 lung cancer cases and 156 controls and subjected to PCR for amplification. Genotyping was carried out with RFLP and DNA sequencing methods. There was no significant difference between lung cancer cases and controls in terms of the distribution of genotyping frequencies of seven HIF-1alpha polymorphisms (P>0.05). No significant relationship was found between the C>T substitution in intron 8 and P582S haplotypes and development of lung cancer. Also, no significant difference was observed between the genotypes and clinopathological characteristics of the cases. These findings showed that polymorphisms of the HIF-1alpha gene did not confer susceptibility to lung cancer.
