Table 1.

Pertinent laboratory investigations for three patients with PCBD1 mutations

Parameter	Patient 1 (BIODEF 272)		Patient 2 (BIODEF 329) Baseline	Patient 3 (BIODEF 319) Baseline	Reference Range
	Baseline	500 mg/d Mg2+
Serum indices
Na+ (mmol/L)	141	—	138	139	135–145
K+ (mmol/L)	4.0	—	4.5	4.0	3.5–5.0
Mg2+ (mmol/L)	0.64a	0.76	0.65a	0.74	0.7–1.1
Ca2+ (mmol/L)	2.41	2.55	2.25	2.43	2.20–2.65
Pi (mmol/L)	1.13	1.16	—	1.15	0.8–1.4
Creatinine (mmol/L)	0.069	0.066	0.062	0.056	0.045–0.110
HbA1c (%)	7.2a	—	4.95	6.5a	4.3–6.1
Uric acid (μmol/L)	310	—	—	—	135–510
Urinary indices
Mg2+ (mmol/L)	6.16	3.96	—	2.6	—
Mg2+ (mmol/24 h)	—	—	5.25	—	2–8
FEMg (%)	6.6a	11.1a	—	3.5	<4
Ca2+ (mmol/L)	4.47	3.04	—	2.99	—
Ca2+ (mmol/24 h)	—	—	5.61	—	<7.5
FeCa (%)	0.9	1.8	—	0.86	>1
Pi (mmol/L)	40.29	13.61	—	18.2	—
FePi (%)	17	17.6	—	—	5–20
Creatinine (mmol/L)	14.29	4.40	—	8.0	—
Creatinine (mmol/24 h)	—	—	14	—	9–18
GFR (ml/min per 1.73 m2)	128	135	—	124	≥90
CCr (ml/min)	—	—	126	—	89–143

FEMg was calculated using the following formula: FEMg=(U_Mg×P_Cr)/[(0.7×P_Mg)×U_Cr×100]. GFR was calculated by the Modification of Diet in Renal Disease formula. FeCa, fractional excretion of Ca²⁺; FePi, fractional excretion of phosphate (Pi); CCr, creatinine clearance.

^aAbnormal value.