An Unusual Case of BSND Gene–Related (Type IV) Bartter Syndrome Presenting as Antenatal Bartter Syndrome:A Case Report and Review of Literature

Bartter syndrome is a group of autosomal recessive renal tubular disorders;it has two types of presentation:antenatal and classic.The antenatal type presents as severe unexplained polyhydramnios in the second trimester.This is due to fetal urinary losses of sodium,chloride,and potassium,leading to fetal polyuria.The classic type presents in the late neonatal or infancy stage,with dehydration,dyselectrolytemia,failure to thrive,and nephrocalcinosis.Antenatal scans are normal in such cases.Type I and II Bartter syndrome presents in the antenatal period,whereas type IV has a classic presentation.We describe an unusual case of type IVa Bartter syndrome presenting in the antenatal period,with severe polyhydramnios.The initial diagnosis was made based on amniotic fluid chloride levels and later confirmed by performing a genetic test.Genetic testing is important for confirming diagnosis and prognostication regarding the condition.

A novel splicing mutation in CLCNKB in a Chinese patient with Bartter syndrome type Ⅲ

Bartter syndrome type Ⅲ is a Bartter syndrome subtype, which has a group of autosomal-recessive inherited disorders with clinical characteristics such as renal salt wasting, hypokalemic metabolic alkalosis,elevated renin and aldosterone levels, with normal or low blood pressure.1 Unlike other subtypes that often begin in the neonatal period, type Ⅲ, due to mutations in the CLCNKB gene,2-4 is highly variable and usually presents as a ＂classic＂ Barrter variant characterized by an onset in early childhood and less severe or absent hypercalciuria and nephrocalcinosis.

Concurrence of Bartter syndrome and minimal change nephrotic syndrome

Nephrotic syndrome （NS） is a common disease in children with a group of symptoms including heavy proteinuria （≥50 mg/kg per 24 hours）, hypoalbuminaemia, hypercholesterolaemia and edema. Bartter syndrome （BS） is a clinically and genetically heterogenous kidney disease characterized by hypokalemia, hypochloremic metabolic alkalosis, obvious increase of rennin, angiotesin II, and normal blood pressure. Cases of Banter syndrome were frequently reported in recent years, but the Bartter syndrome accompanied by nephrotic syndrome as the first symptom has not been previously reported. Although BS is not classically associated with proteinuria, there have been a few reported cases of concomitant focal segmental glomerulosclerosis （FSGS） with BS.1-6 Recently, Hanevold et al5 and Sardani et al7 respectively described an African American child with BS and proteinuria whose renal biopsy revealed findings consistent with Clq nephropathy （ClqN）, as well as the expected hyperplasia of the juxtaglomerular apparatus （JGA） which is characteristic of BS. It was previously reported that BS was first diagnosed, and then gradually proteinuria followed, but the simultaneous presence of BS and NS is unusual. We herein present a boy with BS and NS whose renal biopsy revealed findings consistent with glomeruli minimal change disease and BS.