Q1) What is Osteogenesis Imperfecta ?
A1) Osteogenesis Imperfecta includes a group of inherited disorders characterized by increased bone fragility. The bones are weak or brittle and result in fractures from a very early age, even with minor force or trauma. There are many types of Osteogenesis Imperfecta based on the genetic mutation ranging from very severe to mild disease. The most severe forms can result in fractures in utero as well, these children can have fractures as early as 1st or 2nd day of life.
Q2) What causes Osteogenesis Imperfecta ?
A2) It is caused by a defects in a protein called type 1 collagen which is essential for bones tendons, ligaments, teeth, and the whites of the eyes. Mutations in the gene responsible for collagen production result in Osteogenesis Imperfecta, resulting in defective or reduced collagen production. About 80%–90% of OI cases are caused by autosomal dominant mutations in the type 1 collagen genes, COL1A1 and COL1A2. Most severe forms have mutations in both the genes.
Q3) What are the features of Osteogenesis Imperfecta?
A3) Children with OI can have a range of symptoms depending upon the underlying mutations, but the hallmark of this disease is fractures with minimal or sometimes no trauma due to weak bones. The commonly seen features are:
- Loose joints and muscle weakness.
- Blue, purple, or gray tint to sclera (whites of the eyes)
- Triangular face.
- Increased spinal deformity with potential for compression of the vertebrae
- Delayed teeth eruption, change in strength and color of teeth.
- Possible hearing loss.
- Short stature
Q4) How can Osteogenesis Imperfecta be diagnosed ?
A4) Osteogenesis Imperfecta is suspected in babies who have fractures at a very early age, some even in utero, immediately after birth with minimal or no trauma. Some children might have a blue sclera which also points in the direction of Osteogenesis Imperfecta. The diagnosis can be confirmed by doing Genetic Testing for Osteogenesis Imperfecta. It is a blood test in which the genes responsible for OI are identified and the disease classified.
Q5) What is the treatment for Osteogenesis Imperfecta ?
A5) There is no cure for Osteogenesis Imperfecta yet. The goal of treatment is to improve bone health, muscle mass and decrease the number of fractures. The management of OI consists of both medical and surgical interventions, depending upon the severity of the disease.
Medical management comprises a group of drugs called – Bishosphonates, most commonly used are pamidronate and zoledronic acid. These drugs improve the bone density and help to reduce the number of fractures, decreased pain and better mobility. These are given as intravenous infusions every 3-6months under supervision of a Pediatric Endocrinologist. Regular infusions have been documented to reduce fracture rates in children with OI.
Surgical management is required to correct bone deformity. Rods are used to prevent bones from breaking and to also support bones.
Children with OI also require Occupational and Physical therapy to improve muscle power, tone and to aid in day to day activities.