- Detection of a R173W mutation in the porphobilinogen deaminase gene in the Nova Scotian "foreign Protestant" population with acute intermittent porphyria: a founder effect. Greene-Davis, S.T., Neumann, P.E., Mann, O.E., Moss, M.A., Schreiber, W.E., Welch, J.P., Langley, G.R., Sangalang, V.E., Dempsey, G.I., Nassar, B.A. Clin. Biochem. (1997)