Deciphering Growth Patterns in Korean Children With Sotos Syndrome Through the Development of a Disease-Specific Growth Chart.

Background: Sotos syndrome (SS) is a rare disorder characterized by overgrowth, distinctive facial features, and intellectual disability that is primarily caused by NSD1 pathogenic variants or 5q35 microdeletions.

Methods: We retrospectively analyzed the clinical characteristics and 339 anthropometric measurements over an average of 4.3 years of follow-up in 57 Korean children with SS. Sex-specific percentile curves for height, weight, and head circumference were developed using a generalized additive model that included factors such as location, scale, and shape.

Results: Males with SS demonstrated higher height before the age of 12.0, greater weight before 10.0, and larger head circumference before 15.5 compared to age- and sex-matched controls. Females with SS displayed higher height before 17.0, greater weight before 10.5, and larger head circumference before 12.0 compared to controls. Bone age was advanced compared to chronological age in 40% of males and 8% of females at their last visit. The predicted and target adult heights were not significantly different between groups. In subgroup analysis, the intragenic variant group (n = 48) showed a higher mean standard deviation score of height and weight in males, and head circumference in females compared to the microdeletion group (n = 9).

Conclusions: Korean children with genetically confirmed SS exhibited overgrowth in height, weight, and head circumference. Overgrowth phenotypes were more prominent in patients with NSD1 intragenic variants than in those with microdeletions. This is the first study to provide reference data on the growth of Korean children with SS.