Types

Type I: 

• Slight spinal curvature
• blue sclera
• Poor muscle tone
• loose joints
• dentinogenesis imperfecta

TypeII:       

• Most cases die within the first year of life due to respiratory failure or intracerebral hemorrhage
• Severe respiratory problems due to underdeveloped lungs
• Severe bone deformity and small stature

Type III:   

• Short stature, spinal curvature and sometimes barrel-shaped rib cage
• Triangular face
• Loose joints (double jointed)
• Discolouration of the sclera (the 'whites' of the eyes are blue)

Type IV:

• Bones fracture easily, especially before puberty
• Short stature, spinal curvature, and barrel-shaped rib cage
• Bone deformity is mild to moderate
• Early loss of hearing

Type V:It is distinguished by "mesh-like" bone appearance.

Type VI:With the same clinical features as Type IV, it is distinguished histologically by "fish-scale" bone appearance.