Disease

Protein

Inheritance

Normal Repeat Number

Range of CAG Repeats in Disease

Spinobulbar Muscular Atrophy (Kennedy’s disease) (La Spada et al., 1991)

androgen receptor

X-linked dominant

11 - 33

40 - 62

Huntington’s Disease

(Huntington's Disease Collaborative Research Group, 1993)

huntingtin

autosomal dominant

1 - 39

36 - 121

Spinocerebellar Ataxia, type 1 (SCA1) (Orr et al., 1993)

ataxin-1

autosomal dominant

<29 - 36

43 - 60+

Spinocerebellar Ataxia, type 2 (SCA2) (Pulst et al., 1996)

ataxin-2

autosomal dominant

15 - 24

35 – 59

Spinocerebellar Ataxia, type 3 (SCA3, Machado-Joseph Disease) (Kawaguchi et al., 1994)

ataxin-3

autosomal dominant

13 – 36

62 – 82

Spinocerebellar Ataxia, type 6 (SCA6) (Zhuchenko et al., 1997)

a_1a subunit of voltage-dependent calcium channel

autosomal dominant

4 – 16

21 – 27

Spinocerebellar Ataxia, type 7 (SCA7) (David et al., 1997)

ataxin-7

autosomal dominant

7 – 17

38 – 130

Dentatorubralpallidoluysian atrophy (DRPLA) (Koide et al., 1994)

atrophin-1

autosomal dominant

7 – 25

49 – 85