Clinical Features of Seven COL2A1 Variations in Chinese Children With Type II Collagen Disorders.

Aim: Type II collagen, encoded by the collagen type II alpha 1 (COL2A1) gene, is crucial for the structure of cartilage. This study aims to improve our understanding of Spondyloepiphyseal Dysplasia Congenita (SEDC) caused by mutations in COL2A1. We also aim to evaluate the safety and efficacy of growth hormone (GH) therapy in two SEDC patients.

Methods: We performed genetic analyses of seven paediatric patients from unrelated Chinese families. Two patients received GH therapy, and their growth trajectories were monitored over 3.5 and 3 years.

Results: Genetic screening identified six missense mutations (Gly1110Ser, Gly1107Glu, Gly873Arg, Gly456Ala, Gly1062Ser and Gly1182Arg) and one intron variant in COL2A1. All patients (five girls and two boys, ranging from 2 years and 7 months to 12 years) were diagnosed with SEDC, exhibiting disproportionate short stature and skeletal abnormalities. GH therapy resulted in height increases of 0.76 and 0.27 standard deviation scores over 3.5 and 3 years, respectively, with no significant side effects.

Conclusion: This study expands the mutation spectrum of COL2A1 and supports the efficacy and safety of GH therapy in SEDC patients, highlighting the need for multi-center studies to further investigate GH's therapeutic potential.