Osteogenesis imperfecta type I - mild disease

The International Society of Skeletal Dysplasias classifies osteogenesis imperfecta based on inheritance pattern and the genes involved. (1)

Type I (non-deforming) ostoegenesis imperfecta is the commonest and mildest form. It typically follows an autosomal dominant inheritance pattern and is associated with mutations in COL1A1 and COL1A2. An X-linked variant has also been identified and is associated with mutations in the PLS3 gene. (2)

Features include:

• inherited in an autosomal dominant manner
• presentation is in childhood
• fractures occur throughout life
• deformity is rare

This type of osteogenesis imperfecta is caused by abnormal or decreased synthesis of pro-alpha1 or pro-alpha2 collagen polypeptides.

Reference

1. Warman ML et al. Nosology and classification of genetic skeletal disorders: 2010 revision. Am J Med Genet A. 2011 May;155A(5):943-68.
2. Marom R, Rabenhorst BM, Morello R. Osteogenesis imperfecta: an update on clinical features and therapies. Eur J Endocrinol. 2020 Oct;183(4):R95-106.