Table 1.

Analysis of patients

	CK	IVCT data
	Hal 2%	Caf 2 mM
III: 3	75	6N	5N
II: 2	168	10N	6N
II: 1	51	<2N	<2N

CK levels and IVCT data of the proband (III.3) and two individuals from the family (II.2 and II.1). CK = Creatine Kinase activity is expressed in international units per liter (IU/L; normal <205). IVCT = In Vitro Contracture Test. Hal = tension in Newton (N) at 2% halothane, the normal value being <2N. Caf = tension at 2 mM Caffeine, the normal value being <2N.