Table 1.

Parameter estimates for the bone length models for boys with Progeria in comparison to those of normal boys. $L$ is the length at birth, $H$ is the eventual bone length, (${\beta }_1$, ${\beta }_2$, ${\beta }_3$) determine the growth rate, and $\delta$ is the difference in eventual bone lengths based on childhood ($H_{child}$) and adolescent ($H_{adol}$) measurement methods. Ratios refer to Progeria/normal ratios for adolescent asymptotes and Progeria/normal ratios for half-lives (the time taken to grow from $L$ to half the distance between $L$ and H). For each bone, all parameters ($L$, $H$, $\delta$ and (${\beta }_1$, ${\beta }_2$, ${\beta }_3$) taken as a group) were significant (p<0.001).

		$L$ (cm)	$H+\delta$ $H_{child}$ (cm)	$H$ $H_{adol}$ (cm)	ratio for asymptote	${\beta }_1$	${\beta }_2$	${\beta }_3$	half-life	ratio for half-life
Humerus	Normal	6.9	34.6	37.4	-	0.14	−0.012	0.0007	7.4	-
	Progeria	6.9	20.8	22.8	0.61	0.19	−0.013	0.0006	4.9	0.66
Radius	Normal	5.6	26.0	28.1	-	0.14	−0.012	0.0008	7.8	-
	Progeria	5.6	14.6	15.8	0.56	0.29	−0.030	0.0015	3.4	0.44
Ulna	Normal	6.2	28.6	30.0	-	0.14	−0.013	0.0008	7.9	-
	Progeria	6.2	16.6	17.2	0.57	0.25	−0.027	0.0015	4.2	0.53
Tibia	Normal	6.3	38.9	44.3	-	0.16	−0.015	0.0010	6.5	-
	Progeria	6.3	24.1	26.7	0.60	0.25	−0.028	0.0017	4.1	0.64
Fibula	Normal	6.0	38.6	43.1	-	0.16	−0.014	0.0009	6.4	-
	Progeria	6.0	21.8	24.5	0.57	0.28	−0.028	0.0015	3.4	0.52