Phenotype and genotype characteristics of 58 patients showing a prolonged effect of succinylcholine: A four-year experience.

INTRODUCTION:This study sought to describe the phenotype and genotype characteristics of patients referred to our laboratory to undergo further assessment due to a suspicion of a prolonged effect of suxamethonium attributed to BChE deficiency. METHODS:All patients referred to our laboratory from January 2016 to December 2019 due to the suspicion of a prolonged effect of suxamethonium were included in this study. The determination of BChE activity and genotyping using complete nucleotide sequencing of the entire complementary DNA-coding region with flanking intron-exon boundaries were completed. RESULTS:During this four-year period, 58 patients were referred to our laboratory for the investigation of prolonged neuromuscular block due to BChE deficiency. Among them, 52 showed a BChE deficiency related to BCHE gene mutations. The most commonly detected genotype was compound homozygous atypical variant (p.Asp98Gly)/homozygous Kalow variant (p.Ala569Thr) (p.[Asp98Gly;Ala567Thr];[p.Asp98Gly;Ala567Thr]). Further, we recorded four new BCHE variants, which seem to be associated with prolonged post suxamethonium apnoea: p.(Trp205Cys), p.(Leu222His), p.(Glu469Gln), and p.(Lys276Ter). CONCLUSION:During a four-year period, among the 58 patients referred to our laboratory, we have found four new BCHE variants, which seem to be associated with prolonged post suxamethonium apnoea (p.(Trp205Cys), p.(Leu22His), p.(Glu469Gln), and p.(Lys276Ter)).