The genetics of the alternative pathway of complement in the pathogenesis of HELLP syndrome

Objective: Recent preliminary evidence suggests that gene mutations in the alternative pathway of complement may play a crucial role in the pathogenesis of HELLP syndrome. To verify this hypothesis, a consecutive series of women who developed the syndrome was screened for variants in alternative pathway genes. Methods: The coding sequences and intron-exon boundaries of the complement factor H (CFH), complement factor I (CFI), Membrane Cofactor Protein (MCP), complement factor B (CFB) and C3 were sequenced in 33 women with a diagnosis of HELLP syndrome. Results: Three patients carried heterozygotic variants - two in CFI and one in MCP. One of the two CFI mutations, was previously described as an unremarkable polymorphism. Conversely, computational analyses for the remaining two cases suggest that they may have a functional impact. Conclusions: The present study confirms that the alternative pathway of complement may play a role in the pathogenesis of HELLP syndrome. However, its overall contribution to the determinism of the syndrome is less relevant than initially reported