Author contributions
All authors were involved in the conceptual design of this manuscript, drafting and development, and agreement to publish. In addition: P.N.N., A.J.S., J.E., J.L., A.M., V.R. were involved in study design; J.E. was responsible for trial initiation and maintenance; C.S. was involved in development and validation of the assay for measurement of AOC3 activity; A.J.S., J.M.S., P.N.N., G.N., V.R., E.L. were the study investigators; E.L. was involved in study consultation; J.M.S, P.N.N., V.R., E.L. were involved in patient enrolment; P.N.N, J.L., A.M., C.S. were involved in data analysis; E.L. was involved in data review; and J.M.S., P.N.N., J.E., J.L., A.M., V.R., E.L. were involved in data interpretation.