Table 1.
Summary of selected clinical and laboratory variables in affected dogs with X‐linked hereditary nephropathy (n = 8) and unaffected (n = 4) littermates (median [range]) at initial onset of each milestone.
| Baseline | Milestone 1 | Milestone 2 | Milestone 3 | Milestone 4 | Milestone 5 | |
|---|---|---|---|---|---|---|
| Microalbuminuria | 2nd UPC ≥ 2 | sCr ≥ 1.2 mg/dL | sCr ≥ 2.4 mg/dL | sCr ≥ 5 mg/dL | ||
| Affected | N = 8 | N = 8 | N = 8 | N = 8 | N = 7 or 6a | N = 6a or 5b |
| Age (weeks) | 7 (7–8) | 13.5 (10–19) | 20 (14–29) | 27 (21–39) | 33 (23–48) | 37a (26–52) |
| sCr (mg/dL) | 0.36 (0.30–0.44) | 0.49 (0.34–0.64) | 0.63 (0.47–0.73) | 1.27 (1.20–1.38) | 2.47 (2.40–2.80) | 5.71a (5.41–6.75) |
| BUN (mg/dL) | 3.5 (2–7) | 4.5 (4–8) | 7.5 (5–10) | 16 (13–27) | 33 (31–50) | 115a (77–128) |
| SDMA (μg/dL) | 13.5 (9–14) | 13 (10–15) | 11.5 (10–15) | 22.5 (17–29) | 36 (29–45) | 69b (54–95) |
| GFR (mL/min/kg) | 5.34 (4.75–5.56) | 4.65 (3.33–5.41) | 3.33 (3.00–4.86) | 1.47 (0.99–1.69) | 0.67 (0.65–0.81) | 0.36b (0.28–0.37) |
| USG | 1.019 (1.005–1.024) | 1.014 (1.009–1.027) | 1.014 (1.003–1.029) | 1.013 (1.012–1.021) | 1.012 (1.008–1.017) | 1.017b (1.014–1.021) |
| UPC | 0.3 (0.2–1.0) | 0.4 (0.3–1.0) | 4.3 (2.0–8.0) | 21.3 (13.6–41.0) | 23.7 (20.6–60.0) | 25.2b (17.6–29.8) |
| Weight (kg) | 4.8 (3.2–5.1) | 10.4 (5.8–17.4) | 16.4 (11.9–21.4) | 19.3 (17.0–25.1) | 19.9 (16.8–24.2) | 15.8a (14.9–20.8) |
| BCS | 2.5 (2.5–3) | 2.75 (2.5–3.5) | 3.25 (2.5–3.5) | 3 (2–3.5) | 2.25a (2–3) | 1.5a (1–1.5) |
| Unaffected* | N = 4 | N = 4 | N = 4 | N = 4 | N = 4 | N = 4 or 3c |
|---|---|---|---|---|---|---|
| Age (weeks) | 7 (7–8) | 13 (10–17) | 19 (14–29) | 24.5 (21–39) | 32.5 (23–43) | 37 (26–49) |
| sCr (mg/dL) | 0.40 (0.32–0.43) | 0.45 (0.36–0.62) | 0.65 (0.45–0.78) | 0.78 (0.58–0.80) | 0.85 (0.65–0.98) | 0.92 (0.69–1.05) |
| BUN (mg/dL) | 5 (3–8) | 4 (3–11) | 7.5 (7–9) | 9.5 (8–14) | 12 (10–13) | 14 (11–15) |
| SDMA (μg/dL) | 12.5 (10–14) | 11.5 (11–15) | 12 (11–15) | 11 (10–12) | 11 (11–14) | 11c (11–11) |
| GFR (mL/min/kg) | 4.96 (4.52–5.32) | 4.80 (3.10–5.39) | 3.64 (2.99–4.41) | 2.80 (2.57–3.73) | 2.45 (2.26–2.67) | 2.36 (2.12–2.41) |
| USG | 1.010 (1.004–1.014) | 1.017 (1.012–1.023) | 1.011 (1.008–1.026) | 1.023 (1.010–1.035) | 1.022 (1.010–1.038) | 1.029 (1.017–1.036) |
| UPC | 0.6 (0.3–0.8) | 0.2 (0.1–0.4) | 0.2 (0.0–0.3) | 0.1 (0.0–0.2) | 0.1 (0.0–0.1) | 0.1 (0.0–0.2) |
| Weight (kg) | 4.5 (3.9–5.8) | 9.3 (6.2–13.6) | 15.6 (11.9–18.0) | 21.2 (17.0–23.4) | 23.8 (21.1–25.8) | 24.4 (23.5–27.5) |
| BCS | 2.75 (2–3) | 2.75 (2.5–3.5) | 3 (2.5–3.5) | 3.25 (3–4) | 3.5 (3–3.5) | 3.5 (3–4) |
sCr, serum creatinine; BUN, blood urea nitrogen; SDMA, symmetric dimethylarginine; GFR, glomerular filtration rate; USG, urine specific gravity; UPC, urine protein creatinine ratio; BCS, body condition score.
*Results used in unaffected dogs correspond with initial onset of each milestone in an affected sibling.
aN = 6 dogs; bN = 5 dogs; cN = 3 dogs.