NPR2 gene variants in familial short stature: a single-center study

NPR2 variants are associated with various short stature and bone dysplasia, such as acromesomelic dysplasia Maroteaux tyoe, individuals with a phenotype similar to Léri-Weill syndrome (LWD), and idiopathic short stature (ISS). However, few studies have reported on the relationship between familial short stature (FSS) and NPR2 variants. This study aimed to explore the relationship between FSS and NPR2 variants through the detection and identification of NPR2 variants in children with FSS, phenotypic description, clear treatment plan, and follow-up of treatment effect.

Children who met the FSS diagnostic criteria and had informed consent were included in the study. The trio whole-exome sequencing method (trio-WES) was used to detect and evaluate the NPR2 variants.

A total of 16 children with short stature were included in this study (pretreatment height ≤ -2 standard deviation (SD) in both the patient and the shorter parent, unknown genetic etiology). NPR2 variants were identified in 12.5%(2/16) of the participants. Patient A was a 6-year-old male and 103.7 cm tall (-3.11SD), while Patient B was a 9-year-old female and 123.2 cm tall (-1.88SD). However, their heights increased after recombinant human growth hormone (rhGH) treatment. The height of patient A increased by 0.36SD six months after treatment while that of patient B increased by 1.22SD after one and a half years of treatment.

NPR2 variant causes FSS. The growth rate of children significantly improved after rhGH treatment. However, further follow-up study is needed to determine the final height after long-term treatment.