MBL2 gene variants and susceptibility to meningitis in Egyptian patients

Background: Meningitis is inflammation of the membranes enclosing the brain and spinal cord. It is a fatal disease with severe morbidity and mortality. Mannose binding lectin (MBL) encoded by MBL2 gene activates complement system through lectin pathway in innate immunity to defense against the infections.

Objective: The current study aimed to investigate the promoter and exon 1 variants of MBL2 gene among Egyptian patients having meningitis to explore their role in disease susceptibility.

Patients and methods: This case-control study, included 53 patients and 50 sex and age matched controls. MBL2 genotyping was done using Sanger sequencing.

Results: The frequency of one promoter (c.-290C > G) and four in exon 1 (c.161G > A, c.170G > A, c.154C > T and c.132C > T) as well as another one located in its 5'utranslated part (c.-66C > T) variants were estimated. The incidence of the four individual exonic variants was not significantly different between cases and healthy individuals (all P > 0.05). The promoter variant, c.-290C > G was found in all examined patients (84.9% of the patients in homozygote state and 15.1% of patients in heterozygous state) with a highly significant variance in the prevalence of this variant between cases and control group (p = 0.0001). Additionally, UTR variant (c.-66C > T) was also significantly higher in patients than controls (P = 0.033).In comparison with clinical outcome, it was found that c.170G > A variant named C allele was associated with favorable outcome in the studied patients (P = 0.025).

Conclusion: The results obtained showed that the Promoter (c.-290C > G) and UTR (c.-66C > T) variants of MBL2 gene may be potential risk factors for disease susceptibility in Egyptian cases with meningitis. Our results also proposed that c.170G > A (C allele and CC genotype) could affect the severity and play a protective role in these patients. The other genetic variants of MBL2 gene, including c.132C > T, c.161G > A (A > B), and c.154C > T (A > D) that were investigated, did not show any association with susceptibility or severity of meningitis.