Table 5 Stratification of phenotypic data by PrP^Sc (molecular strain) type (according to the London classification27), according to SPRN genotypes in patients with sporadic Creutzfeldt–Jakob disease

Genotype c.20	Age at disease onset (years)			Duration of disease (months)			PrP^Sc type
	Age at disease onset (years)			Duration of disease (months)			1	2	3	2 + 3
	Mean	SD	Median	Mean	SD	Median	1	2	3	2 + 3
TT	55.3	21.5	62	9.1	13.6	5	6	33	9	2
CT	52.8	23.3	61	6.6	7.5	4	5	17	11	0
CC	57.3	27.2	68	7.3	4.8	7	1	3	1	0

SD, standard deviation.