Case Reports in Pediatrics / 2018 / Article / Tab 1

Case Report

Brief Clinical Report: Hypophosphatasia—Diagnostic Considerations and Treatment Outcomes in an Infant

Table 1

Classification and clinical manifestations of HPP [13, 6, 8, 9].

ClassificationAge at onsetClinical manifestations

PerinatalIn utero or at birthMost 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 perinatalIn 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)

InfantileAfter 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 severeAfter 6 months, before 18 years of ageWide 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

AdultAfter 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-HPPBefore 4–5 years of age(i) Isolated early loss of primary dentition with intact tooth root
(ii) No other characteristic radiologic or histopathologic manifestations