Table 2.

Summary of telomeric SMN1, exons 7 and 8 and centromeric SMN2, exons 7 and 8 copy number across various patient and control groups.

Genotype	Definition of genotype	Copy number	Telomeric SMN region		Centromeric SMN region
			SMN1, exon 7	SMN1, exon 8	SMN2, exon 7	SMN2, exon 8
N/Nb (n = 122)	Negative black controls	0	0 (0%)	1 (0.8%)	15 (12.3%)	33 (27%)
		1	0 (0%)	0 (0%)	20 (16.4%)	55 (45.1%)
		2	60 (49.2%)	54 (44.3%)	73 (59.8%)	31 (25.4%)
		>2	62 (50.8%)	67 (54.9%)	14 (11.5%)	3 (2.5%)
N/Nw (n = 30)	Negative white controls	0	0 (0%)	0 (0%)	2 (6.7%)	2 (6.7%)
		1	0 (0%)	0 (0%)	8 (26.6%)	12 (40%)
		2	29 (96.7%)	28 (93.3%)	18 (60%)	14 (46.6%)
		>2	1 (3.3%)	2 (6.7%)	2 (6.7%)	2 (6.7%)
M1/M1b (n = 75)	Black patients with homozygous SMN1, exon 7 deletion (Mutation 1)	0	75 (100%)	38 (50.7%)	0 (0%)	8 (10.7%)
		1	0 (0%)	22 (29.3%)	4 (5.3%)	15 (20%)
		2	0 (0%)	12 (16%)	63 (84%)	49 (65.3%)
		>2	0 (0%)	3 (4%)	8 (10.7%)	3 (4%)
M1/M1w (n = 30)	White patients with homozygous SMN1, exon 7 deletion (Mutation 1)	0	30 (100%)	24 (80%)	0 (0%)	0 (0%)
		1	0 (0%)	4 (13.3%)	2 (6.7%)	5 (16.7%)
		2	0 (0%)	2 (6.7%)	17 (56.7%)	13 (43.3%)
		>2	0 (0%)	0 (0%)	11 (36.7%)	12 (40%)
M2/M2b (n = 50)	Black patients with homozygous SMN2, exon 7 deletion (Mutation 2)	0	0 (0%)	0 (0%)	50 (100%)	49 (98%)
		1	2 (4%)	0 (0%)	0 (0%)	1 (2%)
		2	16 (32%)	21 (42%)	0 (0%)	0 (0%)
		>2	32 (64%)	29 (58%)	0 (0%)	0 (0%)
M2/M2w (n = 8)	White patients with homozygous SMN2, exon 7 deletion (Mutation 2)	0	0 (0%)	0 (0%)	8 (100%)	8 (100%)
		1	0 (0%)	0 (0%)	0 (0%)	0 (0%)
		2	5 (62.5%)	5 (62.5%)	0 (0%)	0 (0%)
		>2	3 (37.5%)	3 (37.5%)	0 (0%)	0 (0%)
U/Ub (n = 72)	Black patients clinically suggestive of SMA and negative for a homozygous deletion of SMN1, exon 7 (unknown)	0	0 (0%)	0 (0%)	10 (13.9%)	17 (23.6%)
		1	6 (8.3%)	5 (6.9%)	8 (11.1%)	33 (45.8%)
		2	38 (52.8%)	31 (43.1%)	51 (70.8%)	19 (26.4%)
		>2	28 (38.9%)	36 (50%)	3 (4.2%)	3 (4.2%)