A 'silent' cholinesterase gene detected by western blotting

ABSTRACT

A 38 year old Asian Indian female with a history of prolonged succinylcholine-induced apnoea was shown to have negligible levels of serum cholinesterase as determined by the dibucaine number test and quantitative enzyme estimation by the modified Ellman method. Electrophoresis of the patients's serum on a 5-20 percent gradient gel stained with Fast Red TR and O-naphthyl acetate detected no cholinesterase inesterase gene in this individual. A family study was initiated to include 19 other members; a similar pattern of cholinesterase activity could be demonstrated in a sister of proband. Western blotting was performed on the sera of the two sisters and selected family members. The cholinesterase antigenic banding pattern of the sisters' sera expressing the 'silent' gene was similar to controls, with additional bands. The cholinesterase gene segregating in this family correspond to the Type II 'silent' gene was similar to controls, with additional bands. The cholinesterse gene segregating in this family correspond to the Type II 'silent' gene variant which has about 3 percent of usual enzyme activity (AU)