Abstract
<title>Abstract</title> <p>Background Schmid metaphyseal chondrodysplasia (SMCD) is a rare autosomal dominant skeletal dysplasia caused by mutations in the COL10A1 gene, characterized by metaphyseal dysplasia and short stature. The co-occurrence of SMCD with growth hormone deficiency (GHD) is extremely rare. Case presentation : We report a 14-year-old boy with growth retardation and skeletal deformities. Genetic testing identified a de novo heterozygous frameshift mutation in COL10A1 (c.1859delC, p.Pro620Leufs*2). Growth hormone provocation tests revealed partial GHD (peak GH: 5.928 ng/mL and 4.639 ng/mL). After coxa vara correction surgery, recombinant human growth hormone (rhGH) therapy was initiated. Following approximately 4.5 years (54 months) of treatment, the patient's height increased from 123.2 cm to 156.2 cm, and height standard deviation score improved from − 2.74 to -1.72. Gonadotropin-releasing hormone agonist (GnRHa) was added upon puberty onset to delay epiphyseal closure. No adverse skeletal events were observed during the entire treatment period. Conclusions This case suggests that endocrine evaluation is essential for children with SMCD. Under close monitoring, rhGH therapy, with GnRHa combination when indicated, may be a safe and effective option to improve height outcomes in such patients.</p>