Simple confirmation methods for rare but impaired variants of human flavin-containing monooxygenase 3 (FMO3) found in an updated genome resource databank

Drug Metab Pharmacokinet. 2023 Aug 23;53:100528. doi: 10.1016/j.dmpk.2023.100528. Online ahead of print.ABSTRACTForty-seven new nonsense or missense human flavin-containing monooxygenase 3 (FMO3) variants were recently identified in an updated Japanese population reference panel. Of these, 20 rare single-nucleotide substitutions resulted in moderately or severely impaired FMO3 activity. To easily identify these 20 FMO3 variants (2 stop codon mutations, 2 frameshifts, and 16 amino-acid substitutions) in the clinical setting, simple confirmation methods for impaired FMO3 variants are proposed using polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) or allele-specific PCR methods. Using PCR-RFLP, FMO3 variants p.Arg51Gly, p.Met66Lys, p.Asn80Lys, p.Val151Glu, p.Val187fsTer25, p.Gly193Arg, p.Val283Ala, p.Asp286His, p.Val382Ala, and p.Phe451Leu were digested by the designated restriction enzymes and confirmed using reference cDNAs. In contrast, the FMO3 variants p.Gly39Val, p.Arg238Ter, p.Arg387Cys, p.Arg387His, p.Leu457Trp, and p.Met497Arg were not digested, whereas the wild type was digested. FMO3 variants p.Gly11Asp, p.Lys416fsTer72, p.Gln427Ter, and p.Thr453Pro were confirmed using allele-specific PCR systems. The previously identified FMO3 p.Arg500Ter variant has a relatively high frequency and was differentiated from p.Arg500Gln in two steps, i.e., enzyme restriction followed by allele-specific PCR, similar to the method for p.Arg387Cys and p.Arg3...

Source: Drug Metabolism and Pharmacokinetics - October 19, 2023 Category: Drugs & Pharmacology Authors: Makiko Shimizu Miaki Makiguchi Yuka Yokota Erika Shimamura Moegi Matsuta Yuria Nakamura Mizuki Harano Hiroshi Yamazaki Source Type: research