“…As indicated earlier, Der p 1 is polymorphic. A number of naturally occurring variants have been identified; they include A 3 G, H 50 Y, H 72 S, E 81 K, A 124 V, S 136 T and E 215 Q (17,54), The mutations occur mainly on surface-exposed residues and, on the basis of the model, they are unlikely to account for functional deficits (unpublished observations).…”