Table 1.

List of coding repeat expansion disorders, sorted according to their year of discovery

ID year	Disordera	Inheritanceb	Chr	Gene	Repeat motif	Normal repeat range	Pathological repeat range	Pathological mechanism(s)c	ID methodd	Ref
1991	SBMA	XLR	Xq12	AR	CAG	9–36	≥38–68	polyQ, RNA?	L, CGA	La Spada et al.10
1993	HD	AD	4p16.3	HTT	CAG	6–35	≥36–250	polyQ, RNA?	L, ExScr	The Huntington’s Disease Collaborative Research Group11
1993	SCA1	AD	6p22	ATXN1	CAG	6–38	≥39–88	polyQ, RNA?	L, ExScr	Orr et al.12
1994	DRPLA	AD	12p13.31	ATN1	CAG	3–35	≥48–93	polyQ, RNA?	L, ExScr	Koide et al.,13 Nagafuchi et al.14
1994	SCA3	AD	14q32	ATXN3	CAG	12–44	≥55–87	polyQ, RNA (foci)	L, cl	Kawaguchi et al.15
1996	SCA2	AD	12q24	ATXN2	CAG	13–31	≥32–500	polyQ, RNA?	L, cl	Pulst et al.16
1996	SCA7	AD	3p21	ATXN7	CAG	4–33	≥37–460	polyQ, RNA?	L, cl	Lindblad et al.17
1996	SPD1	AD	2q31.1	HOXD13	GCG	15	24	polyA (DN)	L, CGA	Akarsu et al.18
1997	SCA6	AD	19p13	CACNA1A	CAG	4–18	≥20–33	polyQ, RNA?	L, ExScr	Zhuchenko et al.19
1997	BCCD	AD	6p21	RUNX2	GCN	17	27	polyA (DN/LoF?)	L, CGA	Mundlos et al.20
1998	OPMD	AD	14q11.2	PABPN1	GCG	6–10	≥12–17	polyA (DN/LoF?)	L, ExScr	Brais et al.21
1999	SCA17	AD	6q27	TBP	CAG (or CAG/CAA)	25–40	≥43–66	polyQ, RNA?	L, CGA	Koide et al.22
2000, 2002	HFGS	AD	7p15.2	HOXA13	tract 1: GCN	14	22	polyA (DN/LoF?)	L, CGA	Goodman et al.,23 Utsch et al.24
					tract 2: GCN	12	18
					tract 3: GCN	18	24–-30
2001	HDL2	AD	16q24.2	JPH3	CAG	6–28	≥41–58	polyQ, RNA (foci)	L, RED	Margolis et al.25
2001	BPES	AD	3q23	FOXL2	GCN	14	19–24	polyA (LoF)	L, CGA	De Baere et al.26
2001	HPE5	AD	13q32	ZIC2	GCN	15	25	polyA (LoF)	L, CGA	Brown et al.27
2002	EIEE1	XLR	Xp21.3	ARX	tract 1: GCN	16	23	polyA (DN)	L, CGA	Strømme et al.28
					tract 2: GCN	12	20
2002	MRGH	XLR	Xq26.3	SOX3	GCN	15	26	polyA (LoF)	L, CGA	Laumonnier et al.29
2003	CCHS	AD	4p13	PHOX2B	GCN	20	25–29	polyA (DN)	L, CGA	Amiel et al.30

ID, identification; chr, chromosome; ref, reference(s)

^aBCCD, brachydactyly and cleidocranial dysplasia; BPES, blepharophimosis, ptosis and epicanthus inversus; CCHS, congenital central hypoventilation syndrome; DRPLA, dentatorubral-pallidoluysian atrophy; EIEE1, early infantile epileptic encephalopathy type 1; HD, Huntington disease; HDL2, Huntington disease-like 2; HFGS, hand-foot-genital syndrome; HPE5, holoprosencephaly type 5; MRGH, mental retardation with isolated growth hormone deficiency; OPMD, oculopharyngeal muscular dystrophy; SBMA, spinal and bulbar muscular atrophy; SPD1, synpolydactyly type 1; SCA, spinocerebellar ataxia

^bAD, autosomal dominant; XLR, X-linked, recessive

^cpolyA (DN), polyAlanine tract associated with dominant-negative effect; polyA (LoF), polyAlanine tract leading to a loss of function of the protein; polyQ, polyGlutamine protein toxicity; polyG, polyGlycine peptide toxicity; RNA, RNA toxicity

^dcl, cloning; CGA, candidate gene analysis; ExScr, expansion screening; L, linkage; RED, repeat expansion detection