Growth patterns in children with mucopolysaccharidosis I and II.

BACKGROUND Mucopolysaccharidosis (MPS) diseases lead to a profound disruption in normal mechanisms of growth and development. This study was undertaken to determine the general growth of children with MPS I and II. METHODS The anthropometric data of patients with MPS I and II (n=76) were retrospectively analyzed. The growth patterns of these patients were analyzed and then plotted onto Polish reference charts. Longitudinal analyses were performed to estimate age-related changes. RESULTS At the time of birth, the body length was greater than reference charts for all MPS groups (Hurler syndrome, P=0.006; attenuated MPS II, P=0.011; severe MPS II, P<0.001). The mean z-score values for every MPS group showed that until the 30th month of life, the growth patterns for all patients were similar. Afterwards, these growth patterns start to differ for individual groups. The body height below the 3rd percentile was achieved around the 30th month for boys with Hurler syndrome, between the 4th and 5th year for patients with severe MPS II and between the 7th and 8th year for patients with attenuated MPS II. CONCLUSIONS The growth pattern differs between patients with MPS I and II. It reflects the clinical severity of MPS and may assist in the evaluation of clinical efficacy of available therapies.