Table 2. Extent of organ atrophy in the Hdh ^Q150/Q150 mice at 22 months of age.

	Mean Weight g (±Std. Error)		Independent samples t-test	% Weight of WT	% Weight of WT
Organ/Tissue	WT 22 month	Hdh Q150/Q150 22 month	2-tailed p values	Hdh Q150/Q150 22 month	R6/2 12 wk previous study [15]
Quadriceps muscle	0.17±0.01	0.09±0.01	p<0.001 *	53	42
Heart	0.18±0.03	0.12±0.01	p = 0.152	67	55
Liver	1.41±0.12	1.19±0.06	p = 0.212	84	75
Kidney	0.22±0.02	0.17±0.02	p = 0.031 *	78	50
Spleen	0.10±0.00	0.09±0.03	p = 0.391	90	67
Testes	0.08±0.01	0.03±0.01	p = 0.005 *	38	15

Organs were removed from perfusion fixed 22 month old Hdh ^Q150/Q150 mice and their wild type littermate controls (n = 4 mice/genotype) and weighed to determine the extent of organ atrophy. These data are compared to those previously calculated for R6/2 mice at 12 weeks of age as compared to wild type littermates.

^*statistically significant.