Table 1.

Summary of clinical and laboratory data.

Clinical characteristics		Case 1 Family 1	Case 2 Family 2	Case 3 Family 3	Case 4 Family 1
Sex		Male	Male	Male	Male
Age of clinical diagnosis (years)		13	33	34	35
Genotype		c.742C>T; p.Q248	17q12 deletion	c.1046-15T>A	c.742C>T; p.Q248
Renal phenotype*		C	d#	C	C
Extra-renal phenotype (during observation)
Pancreas anomaly		Y	Y	Y	N/A
Elevated liver enzymes		N	Y	N	Y
Hypomagnesemia		Y	Y	Y	N
Hyperuricemia		Y	N/A	Y	Y
At diagnosis	sMg	N/A	0.44	N/A	N/A
	sUA	9.7	N/A	6.1	N/A
	eGFR	187	97	79	69
	HbA1c	5.91	20.7	10.4	12.1
	Fasting insulin level	10.6	N/A	N/A	N/A
	Fasting C-peptide	1.41	0.71	0.90	1.43
	Autoantibodies (ICA, GAD, IA2)	Negative	Negative	Negative	GAD, ICA (negative), IA2 (positive)
At last follow-up	Age (years)	22	–	36	46
	sMg	0.61		0.59	0.71
	sUA	5.72		7.2	6.4**
	eGFR	95		47	61
	FEMg	11.4		24.3	11
	HbA1c	5.9		7.1	8.3

eGFR – estimated glomerular filtration rate (ml/min/1.73 m²); FEMg – fractional excretion of Mg²⁺; HbA1c – glycated haemoglobin (%); m, maternal; N/A – not available; p – paternal; sMg – serum magnesium (mmol/l); sUA – serum uric acid (mg/dl); ICA – islet cel autoantibodies; GAD – glutamic acid decarboxylase autoantibodies; IA2 – insulinoma-associated autoantibodies. Laboratory abnormalities are in bold. Hypomagnesemia was considered when sMg <0.7 mmol/l; hyperuricemia when sUA >7 mg/dl or when on allopurinol. Reference values: C-peptide: 1.1–4.4 ng/ml; eGFR >90 ml/min/1.73 m²; HbA1c <6%; FEMg <4%; insulin: 3–17 uU/ml. FEMg was calculated using the following formula: (urine Mg×serum creatinine/0.7×serum Mg²⁺×urine creatinine)×100%.

^*C bilateral cysts; d^# unilateral dysplasia+contralateral cysts;

^**on allopurinol.