Growth in achondroplasia: Development of height, weight, head circumference, and body mass index in a European cohort.

As growth references for achondroplasia are limited to reports from United States, Japan, Argentina, and Australia, the aim of this study was to construct growth references for height, weight, head circumference, and body mass index (BMI) from a European cohort of children with achondroplasia and to discuss the development of these anthropometric variables. A mix of cross-sectional and longitudinal, retrospective, and prospective data from 466 children with achondroplasia and 4,375 measuring occasions were modeled with generalized additive model for location, scale and shape (GAMLSS) to sex-specific references for ages 0 to 20 years. Loss in height position, that is, reduction in height standard deviation scores, occurred mainly during first 2 years of life while pubertal growth seemed normal if related to adult height. Adult height was 132 cm in boys and 124 cm in girls with a variability comparable to that of the general population and seems to be remarkably similar in most studies of children with achondroplasia. BMI had a syndrome-specific development that was not comparable to BMI development in the general population. Weight and BMI might be misleading when evaluating, for example, metabolic health in achondroplasia. Head circumference reached adult head size earlier than in the general population. Increased tempo of head circumference growth necessitates thus close clinical follow-up during first postnatal years.