ESPE Abstracts

Introduction: Salt wasting is a potentially life-threatening condition in the newborn period. Other than 21 OH-CAH other rarer adrenal causes should be considered in the differential diagnosis

Objective: To report the laboratory, clinical features, management and genotype of a series of consecutive patients who showed up at our Center for a salt wasting syndrome in the last 32 years, excluding patients with 21 OH CAH.

Patients & Methods: We retrospectively collected data of 20 children managed in our hospital from 1989 to 2021.

Results: Overall, the mean age at presentation was 19,9 ± 16,2 days of life (1-56 days). Symptoms at presentation were poor growth (80%), vomiting (50%), feeding difficulties (35%), hypotonus (30%), dehydration (30%). At the onset severe hyponatremia (sodium <130 mmol/L) was present in all cases and hyperkalemia (> 7 mmol/L) in 50% of patients. The molecular analysis confirmed the suspected diagnoses in all cases. 35% of children resulted affected by pseudohypoaldosteronism type 1 r (PHA1r), 35% by aldosterone synthase deficiency (ASD), 20% by pseudohypoaldosteronism type 1 r (PHA1s) and 10% by X-linked adrenal hypoplasia congenita (AHC). Although natremia was not significantly different in patients grouped by diagnosis, a significant difference in potassium levels between PHA1s patients (10.6±0.7mmol/l) vs the others (6.8±0.8 mmol/L) (P<0.001) was found. Moreover in PHA1s patients the time onset of symptoms was significantly earlier (5.5 ±2.6 days of life) than the others (23 ± 16 days of life) (P<0,001). According to the pathophysiology of the diseases, all patients with ASD and AHC had high plasma renin levels and low aldosterone levels; conversely, patients with PHA1r and PHA1s showed elevated levels of both. One case was initially suspected for ASD but finally was diagnosed by AHC at 21 months of life when he developed glucocorticoid deficiency.

Conclusions: We found a relative higher incidence of ASD and PHA1r compared to the results of a recent Italian study (Bizzarri C et al. Ital J Pediatr. 2016); PHA1s patients showed an earlier and more severe onset of symptoms associated with life threatening hyperkalemia. In our experience, in patients with hyponatremia, with or without severe hyperkalemia, the adrenal function evaluation should be part of the diagnostic work up even in patient who were already screened for 21 OH-CAH at birth. Early molecular analysis confirmation by a Next Generation Sequencing targeted gene panel could be helpful especially in cases with clinical and laboratory features overlap (AHC, ASD).