Osteogenesis Imperfecta

Osteogenesis Imperfecta and its range of associated symptoms will vary greatly among different individuals. Some may not experience any bone fractures or only a few, while others may be more severely affected and experience multiple fractures. The condition may therefore present symptoms from mild to debilitating. Fractures may initiate at any age.

Origins: Genes and Mutation

People who present with this disease possess a disfunctional gene which fails to tell the body how to make a specific protein. This protein, Type 1 Collagen, is a major component of the connective tissues in bones. It’s important for the formation of ligaments, teeth, and the white outer tissue of the eyeballs.

As a result of the deficiency of Type 1 Collagen, bones can become fragile, breaking easily. This defective gene can be inherited, but this is not always the case. Children can experience a spontaneous mutation that leaves a gene defective. But if a parent has the disease and the child has inherited this, the child’s progression may not reflect that of the parent in either symptoms or degree of disability.

Each person may display a different combination of symptoms – but they all have one thing in common – and that is weaker bones than average. There are some physical indications of the disease: short stature; a triangular-shaped face; breathing problems; hearing loss; brittle teeth; bone deformities such as bowed legs or scoliosis.

As an individual ages, their tendency to fractures decreases considerably. However, the condition may become active again after menopause in women or after the age of 60 in men. Scoliosis, or curvature of the spine, can be a common problem for many children with Osteogenesis Imperfecta. There are four distinct types of the disorder.

Osteogenesis Type I

  • This usually presents as the mildest form of Osteogenesis Imperfecta.
  • It is characterized by multiple bone fractures usually occurring during childhood, through to puberty. Fractures usually begin when an affected child begins to walk. Repeated fractures may result in slight malformation of the bones of the arms and legs (eg: bowing of the tibia and femur).
  • A distinguishing feature associated with Type I is bluish discoloration of the whites of the eyes (blue sclera).
  • Individuals may develop abnormalities affecting the middle and/or inner ears resulting in hearing loss.
  • Individuals may have a triangular facial appearance and an abnormally large head, and be short in stature (macrocephaly).
  • Sideways, or front-to-back curvature of the spine (scoliosis or kyphosis) may occur in some cases.
  • Additional associated symptoms may include: loose (hyper-extensible) joints, low muscle tone (hypotonia), and thin skin that bruises easily.

Osteogenesis Type II

  • Type II is the most severe type of Osteogenesis Imperfecta.
  • Affected infants often experience life-threatening complications at, or shortly after, birth. Extremely fragile bones and numerous fractures present at birth. The ribs and long bones of the legs of affected infants are often malformed.
  • Underdeveloped lungs and an abnormally small upper chest (thorax) may result in life-threatening respiratory problems, and affected infants may experience congestive heart failure.
  • There is a tendency to present with a small, narrow nose, small jaw and an abnormally soft top of the skull.

Osteogenesis Type III & IV

Both these variations are similarly characterised as the above conditions with specific differences and symptoms from mild to severe. Fragile bones, multiple fractures, and malformed bones such as ribs and long bones, become worse as children age.

Common indications would be: short stature; sideways and front-to-back curvature of the spine (scoliosis and kyphosis); respiratory problems; slight blue discoloration to the whites of the eyes (blue sclera) at birth; triangular facial appearance; hearing impairment; discoloured teeth. In Type III in severe cases, progressive bone malformation may result in affected individuals requiring wheelchairs.

Treatments

There are many forms of treatments for the different types of OI, but unfortunately no cure.

  • Surgery can involve the placement of rods into the bones to strengthen them and prevent them from breaking and deforming.
  • Physical therapy can strengthen muscles and teach patients how to prevent breaks.
  • A healthy lifestyle is essential, focusing on a diet rich in calcium, and other bone building nutriments.
  • Exercise can strengthen bones but must be under recommendation and supervision.
  • Maintaining a healthy, steady weight, is also important to avoid putting too much pressure on the bones.

NOFSA (National Osteoporosis Foundation South Africa)

NOFSA is the only non-profit, voluntary health organisation dedicated to promoting lifelong bone health. We focus on reducing the widespread prevalence of osteoporosis while working to find a cure for the disease, and by supporting research and developing programmes of education and advocacy.

Find out more about our work at: www.osteoporosis.org.za