Heterozygous Recurrent Mutations Inducing Dysfunction of Gene in Patients With Short Stature.

Purpose: ROR2, a member of the ROR family, is essential for skeletal development as a receptor of Wnt5a. The present study aims to investigate the mutational spectrum of in children with short stature and to identify the underlying molecular mechanisms.

Methods: We retrospectively analyzed clinical phenotype and whole-exome sequencing (WES) data of 426 patients with short stature through mutation screening of . We subsequently examined the changes in protein expression and subcellular location in caused by the mutations. The mRNA expression of downstream signaling molecules of the Wnt5a-ROR2 pathway was also examined.

Results: We identified 12 mutations in in 21 patients, including 10 missense, one nonsense, and one frameshift. Among all missense variants, four recurrent missense variants [c.1675G > A(p.Gly559Ser), c.2212C > T(p.Arg738Cys), c.1930G > A(p.Asp644Asn), c.2117G > A(p.Arg706Gln)] were analyzed by experiments . The c.1675G > A mutation significantly altered the expression and the cellular localization of the ROR2 protein. The c.1675G > A mutation also caused a significantly decreased expression of c-Jun. In contrast, other missense variants did not confer any disruptive effect on the biological functions of ROR2.

Conclusion: We expanded the mutational spectrum of in patients with short stature. Functional experiments potentially revealed a novel molecular mechanism that the c.1675G > A mutation in might affect the expression of downstream Wnt5a-ROR2 pathway gene by disturbing the subcellular localization and expression of the protein.