(a) Comparison of longitudinal length curves by gender, OI type, and mutant collagen chain demonstrates that males are taller than females and children with type IV are taller than those with type III, while mutant type I collagen chain has no effect. (b) Comparison of longitudinal length curves by gender and OI type, gender and mutant collagen chain, and OI type and mutant collagen chain confirms the significant impact of OI type and lack of length correlation with specific mutant collagen chain. (c) Comparison of composite longitudinal weight curves by gender, OI type, and mutant collagen chain reveals significant impact of OI type. (d) Comparison of composite longitudinal curves of head circumference shows no impact of gender, OI type, or specific mutant collagen chain. For (a,c), * represents significant difference in length or weight, # represents significant difference in rate of increase. For length compared by gender and OI type in (b), * is significant difference in length between type III and IV females, ** is significant difference in rate of length increase between types III and IV OI females, # is significant difference between male and female type IV OI, ## is significant difference in rate of length increase between types III and IV males, *** is significant difference in rate of length increase between male and female type IV OI children. For length compared by OI type and mutant chain in (b), * and + represent significant difference in length and growth rate, respectively, between types III and IV OI children with pathogenic variants in COL1A1; • and ## represents significant differences in length and growth rate, respectively, between types III and IV OI children with pathogenic variants in COL1A2. Significance noted at p < 0.05.