- A homoallelic Gly317-->Asp mutation in ALPL causes the perinatal (lethal) form of hypophosphatasia in Canadian mennonites. Greenberg, C.R., Taylor, C.L., Haworth, J.C., Seargeant, L.E., Philipps, S., Triggs-Raine, B., Chodirker, B.N. Genomics (1993)