Downregulation of ACAN is Associated with the Growth hormone pathway and Induces short stature.

BACKGROUND

ACAN heterozygous mutations can cause short stature in patients with or without advanced bone age and have recently attracted researchers' attention. Growth hormone can be used to treat short stature induced by ACAN mutations; however, few studies have focused on the underlying mechanism of this treatment.

METHODS

Four patients with new mutations were reported based on clinical data and genetic tests. We investigated the expression and Gene Ontology biological process enrichment of ACAN and GH pathways based on GTEx databases through bioinformatics analyses. The effect of ACAN on the growth hormone response evaluated in ATDC5 cells with a growth hormone stimulation test.

RESULTS

Four mutations were reported in this study: c.619C > A, c.1967A > G, c.1888G > A, and c.1308_1309del. All patients' heights were under -2.5 SD, with one had advanced bone age, and two had GH deficiency. Two individuals received growth hormone therapy acquired variable levels of height SD score improvement. ACAN and the GH pathway were strongly associated; ACAN does not affect GHR but regulates the response to GH. Downregulating ACAN inhibited ATDC5 cell proliferation induced by GH.

CONCLUSION

ACAN is associated with the GH pathway, revealing the potential mechanism underlying GH-targeted treatment for ACAN mutation-induced short stature. GH-promoting therapies may increase patients' heights.