Failure to confirm influence of Methyltetrahydrofolate reductase (MTHFR) polymorphisms on age at onset of Huntington disease

Table 2 Linear regression analysis concerning polymorphisms in the MTHFR gene

Gene (polymorphism)	R²	ΔR²	% additional explained variance	P value
HD CAG	.308	-		< .0005
HD CAG + MTHFR A1298C	.304	.004	-	.850
HD CAG + MTHFR C677T	.305	.003	-	.590
HD CAG + compound heterozygotes	.304	.004	-	.828

Variance in age at onset for the CAG repeats is indicated as such as well as in combination with the different polymorphisms examined. R² illustrates the relative improvement of the regression model when the various genotypes are considered in addition to the HD CAG repeats, ΔR² values quantify these differences. P values refer to R².

ISSN: 1477-5751