Table 4: Protein variants, calculated Vrel, and Plasma PPi levels in 7 compound heterozygous GACI patients from the NIH cohort.

The variability of plasma [PPi] in patients with identical pathogenic variants (such as patients GACI04 and GACI05), and the non-correspondance of plasma PPi and Vrel (such as in patient GACI17), suggests that upstream and downstream factors such as ABCC6, Alkaline Phosphatase, and CD73 may be important for plasma [PPi] in individual patients.

Patient	Protein Variant (Vrel)	Age at collection	PPi concentration (μM) (normal 1.37–6.93)
GACI69	c.715+1G>C (not determined)	39y	0.53
	p.Asn792Lys (0.063±0.011)
GACI05	p.Cys480Arg (0.345±0.077)	10y	0.63,
	p.Gly805Val) (0.053±0.014)	12y	0.91
GACI04	p.Cys480Arg (0.345±0.077)	7y	0.70,
	p.Gly805Val (0.053±0.014)	9y	0.27
GACI17	p.Tyr551Cys (0.002±0.006)	5y	1.13
	p.Leu579Phe (0.001±0.002)
GACI22	p.Lys905fsX15 (0.001±0.001)	7y	0.93
	p.Arg481Trp (0.681±0.060)
GACI20	p.Tyr471Cys (0.333±0.048)	29y	0.63
	p.Arg481Gln (1.082±0.092)
GACI09	p.Arg888Trp (0.040±0.006)	12y	0.17
	p.Arg774Cys (0.255±0.018)