Table 4. Known Prevalence of Polyglutamine Diseases Compared With the Prevalence Among Carriers of CAG Repeat Lengths Within the Disease-Causing Range.

Disease	Disease Prevalence per 100 000a	Genotype Frequency per 100 000
SCA1	0.2-2.0	65.8
SCA2	0.1-5.8	59.1
SCA3	0.6-0.8	14.8
SCA6	0.0-0.5	7.3
SCA7	0.1-0.2	0
SCA17	0.2	1052.6
HD	10.6-13.7	139.0
DRPLA	0.5b	0
SBMA	0.3c	16.0c

Abbreviations: CAG, cytosine-adenine-guanine; DRPLA, dentatorubral-pallidoluysion atrophy; HD, Huntington disease; SBMA, spinal bulbar muscular atrophy; SCA, spinocerebellar ataxia.

^aDerived from the literature.^{3,4,5,6,7,8,9,10,11}

^bPrevalence among Japanese.

^cPrevalence among men.