vitamin D-resistant rickets, X-linked; X-linked hypophosphatemic rickets

Epidemiology

• most common form of hypophosphatemia
• incidence of 1 in 20000

Pathology

• impaired phosphate uptake in the kidney, due to abnormal regulation of Na+ phosphate cotransport in the proximal renal tubules.

Genetics

• X-linked dominant
• associated with defects in PHEX (phosphate-regulating neutral endopeptidase)

Clinical manifestations

• skeletal deformities
• growth failure
• craniosynostosis
• paravertebral calcifications
• pseudofractures in lower extremities
• muscular hypotonia with onset in early childhood

Laboratory

• serum phosphate: hypophosphatemia
• PHEX gene mutation

More general terms

• hereditary rickets

Database

• OMIM: https://mirror.omim.org/entry/307800