Table 2.

Disease specific features of congenital hypophosphatemias

	Impaired enteral intake	XLH	ADHR (FGF23)	ARHR DMP1	ARHR ENPP1	ARHR FAM20 C	FD	LNSS	OD	ADHR (SGK3)	TIO	HHRH	Dent’s disease	Cystinosis	Fanconi syndrome
Laboratory
Phosphate	low	low	low	low	low	low	lowb	low	low	low	low	low	low	low	low
TmP/GFR	high	low	low	low	low	low	lowb	low	low	low	low	low	low	low	low
Calcium	normala	normal	normal	normal	normal	normal	normal	normal	normal	normal	normal	normal	normal	normal	normal
Urine calcium excretion	normal	normal	normal	normal	normal	normal	normal	normal	normal	normal	normal	high	high	high	high
Alkaline phosphatase	high	high	high	high	high	high	high	high	high	high	high	high	high	high	high
PTH	normal to high	normal to high	normal to high	normal to high	normal	normal	normal	normal	normal	normal	normal to high	normal to high	normal to high	normal to high	normal to high
25-hydroxyvitaminD	normal	normal	normal	normal	normal	normal	normal	normal	normal	normal	normal	normal	normal	normal	normal
1,25-dihydroxyvitaminD	normal to high	low to normal	low to normal	low to normal	low to normal	low to normal	low to normal	low to normal	low to normal	low to normal	low to normal	normal to high	normal to high	normal to high	normal to high
Intact FGF23	low	high	high	high	high	high	high b	high	high	normal	high	low	low	low	low
iron stores			low
Urine amino acids/protein, glucose, and/or electrolytes													high	high	high
Clinical features
Rickets	X	X	X	X	X	X	Sometimes	X	X	X	If present in childhood	X	X	X	X
Growth impairment	X	X	X	X	X	X	Sometimes	X	X	X	Sometimes	X	X	X	X
Tooth abscesses		X	X	X
Enthesopathy		X	X	X	X
Pseudofractures		X	X	X	X	X				X	X	X	X	X	X
Nephrolithiasis or nephrocalcinosis		c	c	c	c	c					c	X	X	X	X
Osteoarthritis		X
Delayed onset			X								X
Biochemical waxing/Waning			X
Focal bone lesions							X	X	X
Skin lesions							Cafe au- lait macules	Epiderma I nevi
Arterial calcifications					X
Osteosclerosis of long bones						X
Cerebral calcifications						X
Facial dysmorphism						X			X
Seizures								X

Abbreviations listed in alphabetical order: ADHR (autosomal dominant hypophosphatemic rickets), ARHR (autosomal recessive hypophosphatemicrickets), DMP1 (dentin matrix protein 1), ENPP1 (ecto-nucleotide pyrophosphatase/phosphodiesterase 1), FAM20C (family with sequence similarity 20, member C), FGF23 (fibroblast growth factor 23), FD (fibrous dysplasia of bone), HHRH (hereditary hypophosphatemic rickets with hypercalciuria), LNSS (linear sebaceous nevus syndrome), OD (Osteoglophonic dysplasia), PTH (parathyroid hormone), SGK3 (serum- and glucocorticoid- inducible kinase 3), TmP/GFR (transport maximum of phosphate adjusted for glomerular filtration rate), TIO (tumor induced osteomalacia), XLH (X-linked hypophosphatemia).

^aRisk of hypocalcemia during treatment with phosphate.

^bPatients with fibrous dysplasia do not necessarily get hypophosphatemia. It is related to total body fibrous dysplasia burden. Patients with fibrous dysplasia may manifest other signs of McCune-Albright Syndrome.

^cIn these conditions, nephrocalcinosis or nephrolithiasis occurs only as a complication of medical therapy.