1.
A common PCSK9 haplotype, encompassing the E670G coding single nucleotide polymorphism, is a novel genetic marker for plasma low-density lipoprotein cholesterol levels and severity of coronary atherosclerosis.
Chen, SN, Ballantyne, CM, Gotto, AM, Tan, Y, Willerson, JT, Marian, AJ
Journal of the American College of Cardiology. 2005;(10):1611-9
Abstract
OBJECTIVES We sought to determine the effects of PCSK9 variants on plasma low-density lipoprotein cholesterol (LDL-C) levels, severity of coronary atherosclerosis, and response to statin therapy in the Lipoprotein Coronary Atherosclerosis Study (LCAS) population. BACKGROUND Mutations in PCSK9 cause autosomal-dominant hypercholesterolemia. We hypothesized that PCSK9 variants could affect plasma LDL-C in individuals with polygenic hypercholesterolemia. METHODS We sequenced all 12 exons and boundaries to detect novel polymorphisms, and genotyped 372 subjects in LCAS and 319 subjects in a second independent population for six polymorphisms, including novel leucine repeats, by fluorescently tagged markers. We reconstructed haplotypes using a Bayesian algorithm. RESULTS Permutation test results showed statistically significant differences in global haplotype distribution among the tertiles of LDL-C (odds ratio [OR]: 2.36, 95% confidence interval [CI]: 1.90 to 4.32, p = 0.005) and minimum lumen diameter of coronary lesions (OR: 1.83, 95% CI: 1.01 to 3.55, p = 0.045). Regression analysis identified haplotype 3 as an independent determinant of LDL-C levels (adjusted R2 = 2.2%, F = 9.37, p = 0.002). Haplotype structure analysis identified E670G as the determinant variant, exerting a dose effect (GG > EG > EE) and accounting for 3.5% of plasma LDL-C variability (F = 14.6, p < 0.001). Plasma total cholesterol, apolipoprotein B, and lipoprotein (a) levels were also associated with the E670G variant. Distributions of the E670G genotypes in an independent normolipidemic and the hyperlipidemic LCAS populations were significantly different (F = 7.2, p = 0.027). No significant treatment-by-genotype interactions were detected. The false positive report probability was between 2% and 8%. CONCLUSIONS Haplotype 3 encompassing the E670G variant is an independent determinant of plasma LDL-C levels and the severity of coronary atherosclerosis.
2.
Surgical outcome in mesial temporal sclerosis correlates with prion protein gene variant.
Walz, R, Castro, RM, Velasco, TR, Alexandre, V, Lopes, MH, Leite, JP, Santos, AC, Assirati, JA, Wichert-Ana, L, Terra-Bustamante, VC, et al
Neurology. 2003;(9):1204-10
Abstract
BACKGROUND Mesial temporal lobe epilepsy related to hippocampal sclerosis (MTLE-HS) is the most common surgically remediable epileptic syndrome. Ablation of the cellular prion protein (PrP(c)) gene (PRNP) enhances neuronal excitability of the hippocampus in vitro and sensitivity to seizure in vivo, indicating that PrP(c) might be related to epilepsy. OBJECTIVE To evaluate the genetic contribution of PRNP to MTLE-HS. METHODS The PRNP coding sequence of DNA from peripheral blood cells of 100 consecutive patients with surgically treated MTLE-HS was compared to that from a group of healthy controls adjusted for sex, age, and ethnicity (n = 180). The presence of PRNP variant alleles was correlated with clinical and presurgical parameters as well as surgical outcome. RESULTS A variant allele at position 171 (Asn-->Ser), absent in controls, was found in heterozygosis (Asn171Ser) in 23% of patients (p < 0.0001). The PRNP genotypes were not correlated with any clinical or presurgical data investigated. However, patients carrying the Asn171Ser variant had a five times higher chance of continuing to have seizures after temporal lobectomy (95% CI 1.65 to 17.33, p = 0.005) than those carrying the normal allele. At 18 months after surgery, 91.8% of patients with the normal allele at codon 171 were seizure free, in comparison to 68.2% of those carrying Asn171Ser (p = 0.005). CONCLUSIONS The PRNP variant allele Asn171Ser is highly prevalent in patients with medically untreatable MTLE-HS and influences their surgical outcome. The results suggest that the PRNP variant allele at codon 171 (Asn171Ser) is associated with epileptogenesis in MTLE-HS.
3.
Genetic variants of human beta-defensin-1 and chronic obstructive pulmonary disease.
Matsushita, I, Hasegawa, K, Nakata, K, Yasuda, K, Tokunaga, K, Keicho, N
Biochemical and biophysical research communications. 2002;(1):17-22
Abstract
Chronic obstructive pulmonary disease (COPD) is due to interactions between cigarette smoke exposure and other risk factors. Genetic variations of human beta-defensin-1 (hBD-1), an endogenous antimicrobial peptide in the airway, were investigated in 60 patients and 213 healthy volunteers by single-strand conformation and restriction fragment length polymorphism analysis and DNA sequencing. Four nucleotide variations in the 5' and 3' untranslated regions and two nonsynonymous substitutions in the coding region were identified. Of these, a newly found Ile38 variant was observed in 15.0% of patients but only in 2.8% of healthy individuals and was significantly associated with the disease (OR = 6.1, 95% confidence intervals 2.0-8.3, P = 0.0012). More than 80% of those with Ile38 experienced sputum production for more than 3 months during the follow-up period. Genetic variations in hBD-1 may define a high-risk subgroup of COPD where the component of chronic bronchitis is predominant.