Table 5

- Clinical presentation and chemistry results among patients with FHHNC and dRTA.

CharacteristicsFHHNCdRTA
n (%)
Clinical presentation
Accidental discovery5 (29.4)2 (14.3)
FTT4 (23.5)12 (85.7)
UTI7 (41.2)0 (0.0)
Hematuria1 (5.9)0 (0.0)
Loin pain0 (0.0)0 (0.0)
Urine resultsFHHNCdRTANormal range
Mean (95% CI)
Calcium/creatinine (mmol/mmol)2.43 (1.62-3.24)1.51 (0.74-2.28)1-3 years: >1.5
4-7 years: >1
8-14 years:>0.7
FEMg% (mean)15.46 (11.09-19.82)2.52 (1.24-3.79)<5%
TRP% (mean)90.66 (86.48-94.84)83.66 (76.92-90.41)78-91%
Serum results (mmol/L)
Serum sodium139.3 (138.50-140.27)140.6 (138.60-142.72)136-145
Serum potassium3.87 (3.61-4.13)3.14 (2.90-3.38)3.5-5.1
Serum chloride100.94 (98.88-103.00)109.53 (105.51-113.54)98-107
pH7.48 (7.46-7.50)7.25 (7.21-7.30)7.35-7.45
Serum HCO3 (mmol)29.83 (29.31-30.35)17.80 (16.21-19.38)22-26
Serum calcium2.24 (2.15-2.33)2.28 (2.22-2.33)2.12-2.52
Serum phosphate1.38 (1.21-1.56)1.25 (0.96-1.53)0.81-1.58
Serum magnesium0.54 (0.50-0.59)0.81 (0.76-0.86)0.70-1.0
Radiological findingsFHHNCdRTA
n (%)
Stones0 (0.00)3 (20.0)
Nephrocalcinosis17 (100)12 (80.0)
Stone number
Single stone0 (0.00)2 (66.7)
Multiple stone0 (0.00)1 (33.3)
Stone location
Kidney0 (0.00)2 (66.7)
Bladder0 (0.00)0 (0.00)
Ureteric0 (0.00)2 (66.7)
  • FHHNC: familial hypomagnesemia with hypercalciuria and nephrocalcinosis, dRTA: distal renal tubular acidosis, FTT: failure to thrive, UTI: urinary tract infection, FEMg%: fraction excretion of magnesium, TRP%: transtubular reabsorption of phosphate, pH: potential of hydrogen, HCO3: bicarbonate