Salt-Losing Syndrome in a Girl with Type I and II Pseudohypoaldosteronism.

BACKGROUND Pseudohypoaldosteronism (PHA) is characterized by renal tubular resistance to aldosterone and leads to hyponatremia, hyperkalemia, and metabolic acidosis. PHA is divided into 2 types: PHAI and PHAII. PHAI can be dominant (systemic disease) or recessive (renal form). PHAII causes hypertension with hyperkalemia and is recognized mostly in adults. PHA can be a life-threatening disease due to salt-wasting syndrome and severe hypovolemia. CASE REPORT We describe the case of a 2-month-old girl who was admitted to our hospital with hypovolemic shock due to salt-wasting syndrome. Laboratory tests revealed severe electrolyte abnormalities: hyponatremia (Na-116 mmol/L), hyperkalemia (K-10 mmol/L) and metabolic acidosis (pH-7.27; HCO3-12 mmol/L). Serum aldosterone was >100 ng/dL. Genetic analysis confirmed mutations in SCNN1A and CUL3 gene responsible for PHAI and PHAII. Supplementation with NaCl, pharmacological treatment of hyperkalemia, and restriction of potassium in the diet resulted in the normalization of serum electrolytes and proper future development. CONCLUSIONS Pseudohypoaldosteronism should always be considered in the differential diagnosis of hyponatremia and hyperkalemia in children. Salt loss syndrome can lead to hypovolemic shock and, when unrecognized and untreated, to death of a child due to arrythmias and brain edema. The presence of 2 types of PHA in the same patient increases the risk of salt loss and at the same time significantly increases the risk of hypertension because of genetic predisposition and regular diet. Increased salt concentration in sweat and saliva may suggest pseudohypoaldosteronism.

TRANSIENT PSEUDOHYPOALDOSTERONISM SECONDARY TO URINARY TRACT INFECTION IN A MALE INFANT WITH UNILATERAL HYDRONEPHROSIS DUE TO PRIMARY OBSTRUCTIVE MEGAURETER: A CASE REPORT.

We present a case of transient form of type 1 pseudohypoaldosteronism (S-PHA) in a 1.5-month-old male infant who presented with lethargy, failure to thrive, severe hyponatremia (Na=118 mmol/L), hypochloremia (Cl=93 mmol/L) and fever due to urinary tract infection. Potassium levels were normal. Markedly elevated serum aldosterone level and elevated serum renin confirmed the diagnosis of pseudohypoaldosteronism. Renal ultrasound showed grade III hydronephrosis on the left kidney while contrast-enhanced voiding urosonography excluded the existence of vesicoureteral reflux, which raised suspicion of obstructive uropathy at the level of vesicoureteral junction. Serum sodium normalized after several days of intravenous fluids and antibiotic therapy, after which oral supplementation of sodium was introduced. The levels of 17-hydroxyprogesterone, adrenocorticotropic hormone, cortisol and thyroid-stimulating hormone were normal. Functional magnetic resonance urography conducted at the age of 3 months confirmed the diagnosis of primary congenital obstructive megaureter and the infant was referred to a pediatric surgeon. Although a rare occurrence, S-PHA can be a potentially life-threatening condition in infants if not recognized and treated appropriately. Therefore, serum concentrations of electrolytes should be obtained in every child diagnosed with obstructive anomaly of the urinary tract and/or acute cystopyelonephritis. On the other hand, every child diagnosed with S-PHA should be evaluated for obstructive anomaly of the urinary tract.

[Pseudohypoaldosteronisme type I: a rare cause of failure to thrive]. / Une cause rare de stagnation pondérale à la naissance : le pseudohypoaldostéronisme de type I.

We report on a boy, born on term, presenting with a weight loss and a persistent failure to thrive after 10 days despite a normal behavior under bottle-feeding. The clinical examination was normal and biological assessment revealed hyponatremia with hyponatriuria, normal kaliemia and elevated aldosterone values, leading to type I pseudohypoaldosteronism diagnosis. Treatment with salt supplementation allowed growth improvement. The diagnosis was confirmed by the identification of a mutation in the mineralocorticoid receptor. This change was also found in several family members.

[Mechanism of intracerebral calcification in hypoparathyroidism].

The mechanism of intracranial calcification in hypoparathyroidism, more frequently seen in pseudo--than idiopathic hypoparathyroidism, has not been completely elucidated, but may be related more to the duration of hypocalcaemia and hyperphosphatemia than parathyroid hormone itself. Hyperphosphatemia promotes ectopic calcification, especially in blood vessel and periarticular tissue in renal failure, but in brain tissue in hypoparathyroidism. Participation of PTH receptor2 in the brain and superoxide production by mitochondria in hypoparathyroidism should be explored with reference to intracerebral calcification and neurodegenerative diseases.

Effect of hydrochlorothiazide in pseudohypoaldosteronism with hypercalciuria and severe hyperkalemia.

Severe hyperkalemia resistant to treatment with sodium chloride (NaCl) supplements plus cation exchange resins can be found in pseudohypoaldosteronism type I. In a patient with the multiple target organ variant of this condition, hyperkalemia persisted at dangerous levels (8.5 mmol/l) despite large doses of NaCl (50 mmol/kg per day) and cation exchange resins (6 g/kg per day). Hypercalciuria was also present. The total volume of fluids and supplements required was not tolerated orally. Indomethacin (2 mg/kg per day) and later hydrochlorothiazide (2 mg/kg per day) were tried to further correct imbalance. Plasma potassium (K) and Na levels, the urinary Na/K ratio, transtubular potassium gradient (TTKG), and urinary calcium/creatinine (Ca/Cr) ratio were used to evaluate the effect of hydrochlorothiazide. Under treatment, plasma Na was stable (137-144 mmol/l), K levels decreased from 8.5 to 5 mmol/l, urinary Na/K from 90 to 24, and TTKG increased from 0.3 to 1.8. Ca/Cr decreased from 3.5 to 1.5 mmol/mmol. The dosage of cation exchange resins was decreased, oral fluids were tolerated, and the patient's general condition improved. Hence: hydroclorothiazide can be useful in the treatment of severe hyperkalemia and hypercalciuria of pseudohypoaldosteronism type I.