Table 9.

(6b) Predicted concordance rates of MS in first degree relatives of MS probands assuming (Pt₀ = Pt₁), 20% Dominant genes and 80% Recessive genes.

	Number of Susceptibility Genes Required (n)
	16	17	18	30	40	50	60
Frequency of Susceptibility (r)	Predicted Concordance in Non-twin Siblings (Target = 2.9 - 3.8%)
r = 0.25	13.4%	13.4%	13.3 - 13.4%	13.4%	13.4%	13.4%	13.4%
r = 0.33	9.3 - 10.9%	10.5%	10.2 - 11.4%	9.9 - 11.0%	10.1 - 11.9%	9.9 - 12.1%	10.6 - 13.1%
r = 0.5	7.1 - 8.2%	6.5 - 7.5%	6.9 - 7.9%	5.3 - 7.7%	5.6 - 7.0%	5.2 - 7.1%	5.5 - 10.5%
r = 1	4.5 - 5.4%	4.6 - 5.5%	4.4 - 5.2%	3.5 - 4.7%	3.0 - 4.2%	2.8 - 3.6%	2.4 - 6.9%
r = 2	3.8 - 4.5%	3.8 - 4.3%	3.6 - 4.3%	2.5 - 3.5%	2.0 - 2.7%	1.7 - 2.3%	1.4 - 4.9%
r = 4	3.2 - 3.9%	3.1 - 3.7%	2.9 - 3.6%	1.9 - 2.7%	1.5 - 2.0%	1.2 - 1.6%	0.9 - 3.7%
r = 8	2.8 - 3.5%	2.7 - 3.3%	2.6 - 3.1%	1.5 - 2.2%	1.1 - 1.6%	0.8 - 1.2%	0.6 - 2.9%
r = 16	2.5 - 3.1%	2.4 - 2.9%	2.3 - 2.8%	1.3 - 1.9%	0.9 - 1.3%	0.6 - 0.9%	0.5 - 1.1%
Frequency of Susceptibility (r)	Predicted Concordance in Parents/Children (Target = 1.8 - 2.1%)
r = 0.25	13.4%	13.4%	13.3 - 13.4%	13.4%	13.4%	13.4%	13.4%
r = 0.33	9.1 - 10.7%	10.4%	10.0 - 11.3%	8.8 - 11.2%	9.3 - 11.3%	9.6 - 11.9%	10.3 - 13.0%
r = 0.5	6.4 - 7.5%	5.8 - 6.8%	6.2 - 7.2%	4.4 - 6.7%	4.6 - 5.9%	4.1 - 5.9%	4.2 - 9.5%
r = 1	3.2 - 4.0%	3.3 - 4.0%	3.0 - 3.7%	2.0 - 3.0%	1.5 - 2.3%	1.2 - 1.7%	0.9 - 4.1%
r = 2	2.1 - 2.9%	2.0 - 2.4%	1.8 - 2.4%	0.9 - 1.4%	0.6 - 0.9%	0.4 - 0.6%	0.2 - 1.7%
r = 4	1.4 - 1.8%	1.2 - 1.6%	1.1 - 1.5%	0.4 - 0.7%	0.2 - 0.4%	0.1 - 0.2%	0.1 - 0.7%
r = 8	0.9 - 1.3%	0.8 - 1.1%	0.7 - 1.0%	0.2 - 0.4%	0.1 - 0.2%	0.0 - 0.1%	0.0 - 0.3%
r = 16	0.7 - 0.9%	0.6 - 0.8%	0.5 - 0.7%	0.1 - 0.2%	0.0 - 0.1%	0.0%	0.0%

(Targets are in bold)