Growth restriction in children with type B Niemann-Pick disease.

OBJECTIVES: To compare growth of children with type B Niemann-Pick disease (NPD) with disease variables including genotype, organomegaly, bone age, and serum insulin-like growth factor-1 (IGF-1).

STUDY DESIGN: A cross-sectional analysis of growth was performed in 23 children and adolescents with enzymatically and genotypically confirmed NPD. Liver and spleen volumes were measured by quantitative computed tomography and skeletal age by a wrist radiograph.

RESULTS: The mean Z scores for height and weight were -1.24 (29th percentile) and -0.75 (34th percentile). The mean liver and spleen volumes were 2.06 and 13.46 times normal for weight, respectively. Skeletal age was delayed by an average of 2.5 years, and serum IGF-1 level was at or below the 2nd percentile in 8 of 12 patients. Short stature and low weight were significantly correlated with large organ volumes, delayed bone age, and low IGF-1 levels. In contrast to patients with other mutations, individuals homozygous for the DeltaR608 mutation had normal height and weight, markedly less hepatosplenomegaly and bone age delay, and normal IGF-1 levels.

CONCLUSIONS: Abnormal linear growth and delayed skeletal maturation are common in children and adolescents with type B NPD; however, homozygosity for DeltaR608 is associated with normal growth.