Validation of auxological reference values for Japanese children with Noonan syndrome and comparison with growth in children with Turner syndrome

We recently published growth references for Japanese individuals with Noonan syndrome (NS). However, it is uncertain whether these references can be used to evaluate the longitudinal growth of children with NS. In addition, these charts did not include detailed values suitable for clinical practice, and they did not include weight-for-height (WFH) charts. In the present study, we validated the references and established new WFH charts for children with NS. In addition, we investigated the growth patterns of these children by comparing them with those of children with Turner syndrome (TS), as well as with those of the normal population. To validate our reference values, we enrolled 32 subjects from our previous study with data available at both a younger (≤ 5 yr) and an older age (≥ 15 yr). We then investigated longitudinal changes in NS-specific standard deviation scores (SDSs) for height in these subjects. There was no significant difference between the initial and later SDSs (mean difference: -0.12, 95% confidence interval: -0.26-0.023, P = 0.10), suggesting that the references could be applied in clinical practice. We also confirmed that the growth patterns of children with NS in each index are significantly different from those of children with TS. In conclusion, we confirmed auxological reference values for Japanese children with NS.