|
| Classification | Age at onset | Clinical manifestations |
|
| Perinatal | In utero or at birth | Most severe form; symptoms apparent at birth: |
| (i) In utero skeletal changes (profound hypomineralization of the cartilage and bone) |
| (ii) Bony abnormalities: short and deformed limbs and soft calvarium |
| (iii) Respiratory compromise at birth to the first week of birth |
| (iv) Pyridoxine-dependent seizures |
| (v) Nearly always fatal soon after birth |
|
| Benign perinatal | In utero or at birth | (i) Skeletal deformities or hypomineralization in utero |
| (ii) Limb bowing, skin dimples, and rickets as neonates |
| (iii) Mild postnatal course with spontaneous improvement in bony symptoms (can range from odonto-HPP to infantile HPP) |
|
| Infantile | After birth, before 6 months of age | (i) Respiratory failure within weeks to months of birth |
| (ii) Bony abnormalities: deformity of the thorax, fractures, and craniosynostosis |
| (iii) Poor feeding and failure to thrive |
| (iv) Delayed motor milestones |
| (v) Proptosis and mild hypertelorism |
| (vi) Pyridoxine-dependent seizures |
| (vii) Hypercalcemia and hypercalciuria |
|
| Childhood: mild or severe | After 6 months, before 18 years of age | Wide range of severities: |
| (i) Early loss of primary dentition |
| (ii) Bony abnormalities: misshapen skull, tibial bowing, enlarged joints from metaphyseal flaring, and recurrent and poorly healing fractures |
| (iii) Bone pain |
| (iv) Gross and fine motor delay |
|
| Adult | After 18 years of age (usually middle age) | (i) Loss of adult dentition |
| (ii) Bony abnormalities: recurrent fractures with poor healing and low bone mass |
| (iii) Crystal arthropathy |
| (iv) Muscle weakness |
|
| Odonto-HPP | Before 4–5 years of age | (i) Isolated early loss of primary dentition with intact tooth root |
| (ii) No other characteristic radiologic or histopathologic manifestations |
|
