Table 1.

Biochemical findings and clinical features of mouse models with different mutations in the Enpp1 gene

Characteristics	Mouse models with Enpp1 mutations
	p.V246D (asj)	p.H362A	p.T238A
Biochemical features:
Is ENPP1 protein made	No	Yes	Yes
Hydrolysis of ATP	No	Yes	No
Hydrolysis of 2’3’-cGAMP	No	No	No
Plasma PPi	↓	↓	↓
Plasma Pi	↓	Similar to WT mice	↓
Plasma FGF23	↑	Not reported	↑
Plasma PTH	↑	Not reported	↑
Phenotypical features:
Breeding and lifespan	Difficulty breeding beyond 2–3 mo	Normal lifespan and readily breed	Increased mortality beyond 20 wks
Stiffened posture	Yes	No	Less severe than asj mice
Ectopic calcification	Wide spread, many tissues affected	Very minimal (only muzzle, ear, and airway analyzed)	Less severe than asj mice (only joints of forepaws analyzed)
Vascular stenosis	No	Not reported	Not reported
Bone (μCT, histomorphometry)	↓BMD (trabecular and cortical bone)	Not reported	Normal trabecular bone, Moderate changes of cortical bone
Bone (mechanic property)	↓	Not reported	Maximal load similar to WT mice, stiffness and total work less severe than asj mice
Calvarial mineralization	↓	Not reported	↑
Wnt inhibitor Sfrp1 expression	↑	Not reported	↓