ATP6V1B1 mutations in distal renal tubular acidosis and sensorineural hearing loss: clinical and genetic spectrum of five families

Figures & data

Table 1. Clinical and laboratory findings of the five probands with DRTA and hearing loss.

	153–101	423–101	631–101	642–101	953–101
Age at last control (years)	14	16	16	12	16
Age at diagnosis (months)	1	2.5	1.5	10	2
Sex	Male	Male	Female	Male	Female
Birth weight (g)	2850	4000	2730	3500	2000
Presenting clinical manifestations	Weakness, hypotonicity, dehydration	Weakness, hypotonicity	Vomiting, dehydration	Growth and developmental delay, constipation	Weakness, hypotonicity
Weight SDS at last control	−3.664	−1.243	−1.363	−1.369	−1.746
Height SDS at last control	−3.914	−2.071	−2.170	−1.189	−2.562
Medullary nephrocalcinosis	+	+	+	+	+
Severe sensorineural deafness	+	+	+	+	+
Biochemical findings at diagnosis^1
Blood pH (7.35–7.45)	7.10	7.30	7.30	7.23	7.27
Urine pH (5–7)	7	8	7	7	6.5
Serum creatinine (0.5–1.4 mg/dL)	0.5	0.6	0.7	0.5	1.1
Sodium (135–147 mEq/L)	140	138	130	147	143
Potassium (3.5–5 mEq/L)	1.9	1.9	2.2	1.8	2.6
Bicarbonate (23–29 mEq/L)	8	17	15	11	15
Serum anion gap^2 (6–14 mEq/L)	10	12	11	13	10
Phosphate (2.4–4.1 mg/dL)	3	3	2.8	3.5	2.4
Alkaline phosphatase (38–126 U/L)	15	13	15	16	16
Mutation	c.91C>T (p.R31X)	c.232G>A (p.G78R)	c.497delC (p.T166RfsX9)	c.1155dupC (p.I386HfsX56)	c.1155dupC (p.I386HfsX56)

1. Normal range is given in parenthesis; 2. Serum anion gap = Na⁺ − (Cl⁻+ HCO⁻); SDS, standard deviation score; N/A, not available.

Figure 1. Pedigrees along with segregation of identified mutations. Electropherograms of each mutation is provided.