Development of disease-specific growth charts for Argentine Prader-Willi syndrome without growth hormone treatment.

Background: Prader-Willi syndrome (PWS) is a complex genetic disorder characterised by infantile hypotonia, early-onset obesity, intellectual disability, hypopigmentation, small hands and feet, short stature, hypogonadism, and distinctive facial features.

Aim: To generate and report growth curves for height, sitting height, hands and feet length for Argentine children with Prader-Willi syndrome (PWS) without growth hormone treatment.

Subjects and methods: A total of 1174 anthropometric measures were obtained from 167 children (82 boys) aged 0-19 years attending Hospital Garrahan between 1992 and 2019. Standardised techniques were used in patients with molecularly confirmed PWS. The 3rd, 10th, 25th, 50th, 75th, 90th, and 97th percentiles were estimated using the LMS method, which adjusts for skewness. Height data were plotted for comparison with the 50th percentile of the Argentine general population and German PWS without growth hormone treatment.

Results: Growth curves for height, sitting height, hands and feet length were developed from 169 children. Mean adult height was 145.3 cm in females (n = 88) and 153.2 cm in males (n = 81), which are 15.4 and 19.6 cm below the 50th percentile of the Argentine non-PWS population for girls and boys, respectively. Compared with German PWS, Argentine PWS references were 3.3 and 5.9 cm shorter in girls and boys, respectively. Mean sitting height was 9.03 cm in boys and 9.61 cm in girls, shorter than the Argentine non-PWS population.

Conclusion: Differences in adult height between Argentine and German PWS references highlight the importance of local growth standards. Country-specific reference charts are essential tools for identifying growth-impacting conditions and monitoring response to therapy.