Table 3.

Tryptase genotypes and associated basal serum tryptase levels dictated by additional TPSAB1 copy encoding α-tryptase.

Additional TPSAB1 copy number	0	1	2	3	4
Tryptase Genotypes* (TPSAB1, TPSB2)	β,β/β,β; α,β/β,β; α,β/α,β; α,β/β,β,β; β,β/β,β,β; β/α,β; β/β,β	αα,β/β,β; αα,β/α,β; αα,ββ/β,β; αα,ββ/α,β	αα,β/αα,β; ααα,β/β,β; ααα,β/α,β	ααα,β/αα,β	ααααα,β/β,β; ααααα,β/α,β
BST (ng/mL), median (range)	4.1 (0–10.4)	13.6 (6.5–33.9)	22.5 (10.5–39.5)	27.3 (23.4–40)	37 (25.5–62.7)

^*Tryptase genotypes identified to date for this number of TPSAB1 replications. In all cases TPSAB1 replications associated with elevated BST identified encode α-tryptase.