Table 1.
Clinical characteristics according to genetic causes of Bartter syndrome patients.
| SLC12A1 (n = 4) | KCNJ1 (n = 1) | CLCNKB (n = 33) | BSND (n = 1) | Mutation negative or not available (n = 15) | Total (n = 54) | |
|---|---|---|---|---|---|---|
| Male: Female (n) | 2:2 | 1:0 | 18:15 | 1:0 | 11:4 | 33:21 |
| Age of onset (median, month) (range) | 11 (0–17) | 12 | 4.5 (0–271) | 0 | 18 (0–111) | 5 (0–271) |
| Perinatal history | ||||||
| Small for GA, % (n) | 0 | 0 | 11 (3/28) | 0 | 9 (1/11) | 9 (4/45) |
| Preterm infant, % (n) | 100 (4) | 100 (1) | 3 (1/29) | 100 (1) | 55 (6/11) | 28 (13/46) |
| Polyhydramnios, % (n) | 100 (4) | 100 (1) | 36 (8/22) | 100 (1) | 40 (4/10) | 47 (18/38) |
| Initial symptom | ||||||
| Failure to thrive, % (n) | 50 (2) | 100 (1) | 76 (25) | 100 (1) | 27 (4) | 6 (33) |
| Polyuria, % (n) | 50 (2) | 100 (1) | 12 (4) | 100 (1) | 13 (2) | 19 (10) |
| Lethargy, % (n) | 0 | 100 (1) | 12 (4) | 0 | 13 (2) | 13 (7) |
| Muscle cramping, % (n) | 0 | 0 | 15 (5) | 0 | 13 (2) | 13 (7) |
| Clinical presentation, % (n) | ||||||
| Antenatal BS | 24 (1) | 100 (1) | 30 (10) | 100 (1) | 20 (3) | 30 (16) |
| Classic BS | 75 (3) | 0 | 67 (22) | 0 | 73 (11) | 67 (36) |
| Gitelman-like syndrome | 0 | 0 | 3 (1) | 0 | 7 (1) | 3 (2) |
| Family history, % (n) | 25 (1) | 100 (1) | 9 (3) | 0 | 13 (2) | 13 (7) |
| eGFR, mean (range), and clinical manifestations | ||||||
| On the first visit | ||||||
| eGFR, mL/min/1.73m2 | 104.4 (69.9–125.0) | 16.1 | 99.3 (27.7–237.0) | 83.0 | 87.2 (34.6–156.0) | 94.1 (16.1–237.0) |
| SNHL, % (n) | 0 | 0 | 3 (1) | 100 (1) | 7 (1) | 6 (3) |
| Nephrocalcinosis, % (n) | 100 (4) | 100 (1) | 21 (6/29) | 100(1) | 83 (5/6) | 41 (17/41) |
| On the last visit | ||||||
| eGFR, ml/min/1.73m2 | 76.6 (74.5–80.8) | 63.3 | 107.6 (5.0–164.0) | 88.6 | 106.1 (17.0–211.8) | 103.9 (5.0–211.8) |
| Impaired kidney function, % (n) | 0 (0) | 0 | 12 (4) | 0 (0) | 13 (2) | 11 (6) |
| SNHL, % (n) | 0 | 0 | 6 (2) | 100 (1) | 7 (1) | 7 (4) |
| Nephrocalcinosis, % (n) | 100 (4) | 100 (1) | 13 (3/24) | 100(1) | 46 (6/13) | 35 (15/43) |
| Developmental delay, % (n) | 25 (1) | 0 | 12 (4) | 100 (1) | 13 (2) | 15 (8) |
BS, Bartter syndrome; GA, gestational age; eGFR, estimated glomerular filtration rate [calculated using the bedside Schwartz equation for children and CKD-EPI equation for adults]; Impaired kidney function, defined as an eGFRcr < 60 mL/min/1.73 m2; SNHL, Sensorineural hearing loss.