Table 1.

Summary of African ancestry HTT disease and non-disease alleles

Allele types	Allele structure nomenclature	HTT repeat tract						Allele occurrence				Fisher exact test
		Q1		Q2	P1	P2	P3	Non-disease N = 384		Disease N = 68
		CAG		CAACAG	CCGCCA	CCG	CCT	n	%	n	%	p values
Typical alleles	Q1-2-2-6-2	14–17	–	2	2	6	2	11	2.9	–	–	0.384
	Q1-2-2-7-2	15–28	41–55	2	2	7	2	99	25.8	10	14.7	0.064
	Q1-2-2-8-2	17	–	2	2	8	2	5	1.3	–	–	1
	Q1-2-2-9-2	15–28	40	2	2	9	2	29	7.6	1	1.5	0.066
	Q1-2-2-10-2	11–20	40–54	2	2	10	2	71	18.5	20	29.4	0.048
	Q1-2-2-11-2	12–21	–	2	2	11	2	18	4.7	–	–	0.089
	Q1-2-2-12-2	17	–	2	2	12	2	1	0.3	–	–	1
	∗Q1-2-2-13-2	17	–	2	2	13	2	1	0.3	–	–	1
Typical alleles subtotal								235	61.2	31	45.6
Atypical alleles	Q1-2-2-4-3	23	–	2	2	4	3	1	0.3	–	–	1
	Q1-2-2-6-3	15–23	42–44	2	2	6	3	2	0.5	4	5.9	5.587 × 10−3
	Q1-2-2-9-3	12–21	–	2	2	9	3	92	24.0	–	–	9.142 × 10−8
	Q1-2-2-10-3	16	–	2	2	10	3	1	0.3	–	–	1
	∗Q1-4-2-4-3	–	42	4	2	4	3	–	–	1	1.5	0.154
	Q1-4-2-7-3	14–19	–	4	2	7	3	22	5.7	–	–	0.059
	∗Q1-4-2-10-2	16–19	–	4	2	10	2	4	1.0	–	–	1
	Q1-2-0-9-2	16–32	40–58	2	0	9	2	27	7.0	30	44.1	3.119 × 10−13
	Q1-0-0-9-2	–	39–46	0	0	9	2	–	–	2	2.9	0.022
Atypical alleles subtotal								149	38.8	37	54.4

The novel allele structures unique to this study are indicated by an asterisk (∗). The most common non-disease and disease allele structures are indicated in underlined italics. The statistically significant frequency differences between the non-disease and disease alleles are indicated in italics (non-disease alleles: Q¹-2-2-10-2 p = 0.048 and disease alleles: Q¹-2-2-6-3 p = 5.587 × 10⁻³, Q¹-2-2-9-3 p = 9.142 × 10⁻⁸ and Q¹-2-0-9-2 p = 3.119 × 10⁻¹³).