Introduction: Isolated hypoaldestronism is a rare endocrinopathy in a limited number of patients who secrete normal level of cortisol, due to mutation in CYP11B2. In some cases clinical diagnosis can be late and genetic analysis showed difficulties.
Case 1: A 7 month-old girl infant was referred to endocrinology department due to womiting, failure to thrive and severe hyponatremia with unexplained neutropenia. She was born term with 2440 gr. There was no consanguinity between parents. In her physical examination height, weight, relative body mass index were <-2 SDS. She had atopic eczema. In laboratory evaluation; we detected low Na (122 mmol/L), high potassium (5,9 mmol/L) and calsium (11,7 ng/dl) with high plasma renin activity (80,5 ng/ml/hours) and low aldosterone (13,3 pg/ml) level. NaCl and fludrocortisone was initiated. LC/LCMS revealed appropriate serum hormon profile with AS deficiency. A heterozygous change in the CYP11B2 (c.554 C> T (p.T185I)) was detected.
Case 2: A 2 month-old male infant was referred to endocrinology department due to severe hyponatremia with suspected diagnosis of congenital adrenal hyperplasia. He was full term, birth weight of 2700 gr. Parents were first degree cousin. In his examination, dissemine squamatos lession was noticed. He was followed by immunolgy department for severe eczema, protein-losing diarrhea and eosinophilia in the mean time. His weihgt (3190 gr) height (52 cm) and head circumtance (35.5 cm) was <-2 SDS. While Na level was 124 mmol/l, PRA was high (100ng/ml/h) with low aldosterone level (5.4 pg/ml). LC/LCMS was compatible with diagnosis. A heterozygous change was detected in the CYP11B2 gene c.763 G> T (p.Glu255Ter).
In both infants, although mutations do not explain the etiology, it is thought that there may be an additional mutation in a region that affects gene function and that our cases may have compound heterozygous mutations. Because of the additional findings; neutropenia in Case 1 and eosinophilia in Case 2, advanced genetic analysis for Whole Exom Sequencing are carried on.
Conclusion: Aldosterone synthetase deficiency is a rare cause of persistant hyponatremia. Clinical findings vary with age. The association of eosinophilia and neutropenia has not been reported so far. In order to explain for these rare associations, an advanced genetic analyses is needed in rare cases such ours.
19 - 21 Sep 2019
European Society for Paediatric Endocrinology