MSK - Osteogenesis Imperfecta

Question 1

Definition

Answer 1

Autosomal dominant condition that results in brittle bones that are prone to fractures.
- Abnormality in type 1 collagen due to decreased synthesis of pro-alpha 1 or pro-alpha 2 collagen polypeptides

Question 2

Role of collagen

Answer 2

Collagen is a protein that is essential is maintaining the structure and function of bone, as well as skin, tendons and other connective tissues.

Question 3

Types of osteogenesis imperfecta

Answer 3

There are 8 types of osteogenesis imperfecta depending on the underlying genetic mutation, and they vary in their severity.

Question 4

Signs and symptoms

Answer 4

Osteogenesis imperfecta presents with recurrent and inappropriate fractures. There are several associated features:
- Hypermobility
- Blue sclera (the “whites” of the eyes)
- Triangular face
- Short stature
- Deafness from early adulthood
- Dental problems, particularly with formation of teeth
- Bone deformities, such as bowed legs and scoliosis
- Joint and bone pain

Question 5

Key features of Osteogenesis Imperfecta

Answer 5

BLUE SCLERA

Question 6

Typical patient

Answer 6

A young child with unusual and recurrent fractures that would normally make you consider safeguarding, however “you notice a blue discolouration to the sclera”.

Question 7

Diagnosis

Answer 7

• Clinical diagnosis.
• Xrays can be helpful in diagnosing fractures and bone deformities
• Adjusted calcium, phosphate, parathyroid hormone and ALP results

Question 8

Treatment

Answer 8

No cure
Medical treatments include:
- Bisphosphates to increase bone density
- Vitamin D supplementation to prevent deficiency