Synonyms

Brittle Bones Disease

Defect

COLLAGEN GENES (COL1A OR COL1A2) for  TYPES I AND IV ; other genes for rare types of

Brief Description

A genetic disorder in which bones break easily. Sometimes the bones break for no known reason. The cause is a gene defect that affects how you make collagen, a protein that helps make bones strong. Usually you inherit the faulty gene from a parent. Sometimes, it is due to a mutation, a random gene change.

Incidence

1 :10,000 to 30,000

Manifestation

Fractures with minimal or absence of trauma, dentinogenesis imperfect (DI), and in adult years hearing loss; perinatalletahality in some babies to individuals with severe skeletal deformities, mobility impairment and very short stature to nearly asymptomatic individuals with a mild predisposition to fractures, normal stature and normal life span.

Inheritance

Autosomal dominant but minority are de novo mutations: some types are autosomal recessive 

Forms/Types

  • TYPE 1 – has a mild symptoms
  • TYPE 2,3,7,8 – has a severe symptoms
  • TYPE 4,5 and 6 – tend to have more moderate symptoms

Diagnosis 

Clinical diagnosisis based on family history, history of fractures, characteristic physical findings including sclera hue and radiographic findings

Prognosis 

Depending on type ranging from perinatal death, to wheelchair bound to fair.

Treatment/Management 

  • Rehab medicine, Orthopedic therapy, dental care, hearing loss treatment
  • Bisphosphonates/pamidronate infusion

References