Genotyping of FCN and MBL2 polymorphisms using pyrosequencing

A SNaPshot Assay for Determination of the Mannose-Binding Lectin Gene Variants and an Algorithm for Calculation of Haplogenotype Combinations

Mannose-binding lectin (MBL) deficiency caused by the variability in the MBL2 gene is responsible for the susceptibility to and severity of various infectious and autoimmune diseases. A combination of six single nucleotide polymorphisms (SNPs) has a major impact on MBL levels in circulation. The aim of this study is to design and validate a sensitive and economical method for determining MBL2 haplogenotypes. The SNaPshot assay is designed and optimized to genotype six SNPs (rs1800451, rs1800450, rs5030737, rs7095891, rs7096206, rs11003125) and is validated by comparing results with Sanger sequencing. Additionally, an algorithm for online calculation of haplogenotype combinations from the determined genotypes is developed. Three hundred and twenty-eight DNA samples from healthy individuals from the Czech population are genotyped. Minor allele frequencies (MAFs) in the Czech population are in accordance with those present in the European population. The SNaPshot assay for MBL2 genotyping is a high-throughput, cost-effective technique that can be used in further genetic-association studies or in clinical practice. Moreover, a freely available online application for the calculation of haplogenotypes from SNPs is developed within the scope of this project.

Mannose-binding lectin gene polymorphism and risk factors for cardiovascular disease in postmenopausal women

BACKGROUND

Inflammatory responses may be altered in postmenopausal women and predispose to cardiovascular disease (CVD). Genetic factors can also influence susceptibility to CVD. Mannose-binding lectin (MBL) is a component of the innate immune system and an activator of the complement cascade. We evaluated the association of genetic polymorphism of MBL (MBL2) on risk factors for CVD in postmenopausal women.

METHODS

In this cross-sectional study, 311 Brazilian women (age ≥45 years and amenorrhea ≥12 months) were included.

EXCLUSION CRITERIA

presence of previous or current CVD, insulin dependent diabetes, chronic kidney disease, autoimmune diseases and cancer. Clinical, anthropometric and biochemical assessments were performed to evaluate the cardiovascular risk factors. DNA was extracted from buccal cell and polymorphisms at codons 54 and 57 in the MBL2 were determined by polymerase chain reaction (PCR). For statistical analysis, the chi-square and logistic regression (odds ratio, OR) were used.

RESULTS

The presence of the polymorphic allele for codon 54 was found in 25.8% of women (A/B=22.6%, B/B=3.2%) and for codon 57 in 12.2% (A/C=10.8%, C/C=1.4%). The polymorphism at codon 54 was significantly associated with the presence of hypertension (OR 0.55, 95% CI 0.31-0.99, p=0.044) and insulin resistance assessed by HOMA-IR (OR 0.46, 95% CI 0.24-0.91, p=0.025). No significant associations were observed between the polymorphism at codon 57 with risk factors for CVD.

CONCLUSION

In postmenopausal women, the polymorphism at codon 54 of the MBL2 was associated with lower risk for hypertension and insulin resistance that are important risk factors for CVD.