Growth references for height, weight, and head circumference for Argentine children with achondroplasia

In order to prepare growth references for height, weight, and head circumference for Argentine children with Achondroplasia, 228 children (114 boys) aged 0–18 years attending the Growth Clinic at Hospital Garrahan were measured between 1992 and 2009. Centiles were calculated by LMS, a method for summarizing growth data which adjusts for skewness. Curves for centiles are obtained using the formula: \( {{\hbox{C}}_{{100}}}_\alpha (t){ = }M(t){\left( {{1 + }L(t)S(t){Z_\alpha }} \right)^{{1/}L(t)}} \), where Z _α is the normal equivalent deviate for tail area α; C100α is the weight or height centile corresponding to Z _α , t is age in years, and L(t) is (skewness)(t), M(t) is median, S (t) is coefficient variation and C_100α (t) indicates the corresponding values of each curve at age t. Boys and girls centiles for height were similar to USA references in infancy and childhood but lower than that references at adolescence. Final height was 1.7 and 5.1 cm below USA achondroplasia references in girls and boys, respectively. Head circumference centiles were, at all ages, lower than USA references in both genders. Countries need national references for clinical growth assessment of their local population. Likewise, specific local growth references for children with some genetic conditions (such us achondroplasia) are valuable tools for detecting additional conditions affecting growth, for estimating final height and for evaluating the impact of growth-promoting treatments. Conclusion: references presented here can also be used in other countries with similar ethnographics characteristics.