Fig. 1. Identification of heterozygous, missense junctin variants in four families with EHI/MHS.

a Pedigrees of four families with exertional heat illness (EHI) and/or malignant hyperthermia susceptibility (MHS) and with rare junctin variants. Caffeine halothane contracture test (CHCT) results are listed as follows: MHShc = MH susceptible to both halothane and caffeine; MHSh = MH susceptible to halothane alone; MHN = CHCT test negative. N/A = DNA not available for genetic evaluation. Arrow = proband. b Positions of the four junctin variants are shown within the protein domain structures of junctin. The binding sites for RyR1 are also depicted.