ESPN 51th Annual Meeting

ESPN 2018


 
A Rare Cause of Chronic Hyponatremia in an Infant: Aldosterone Synthase Type-2 Deficiency
GÜL YEŞILTEPE MUTLU 1 MEHMET TAŞDEMIR 2 NURAY USLU KIZILKAN 3 ESRA YÜCEL 4 TÜLAY GÜRAN 5 ŞÜKRÜ HATUN 1 HÜLYA KAYSERILI 4 ILMAY BILGE 2

1- DIVISION OF PEDIATRIC ENDOCRINOLOGY, DEPARTMENT OF PEDIATRICS, KOÇ UNIVERSITY SCHOOL OF MEDICINE, ISTANBUL, TURKEY
2- DIVISION OF PEDIATRIC NEPHROLOGY, DEPARTMENT OF PEDIATRICS, KOÇ UNIVERSITY SCHOOL OF MEDICINE, ISTANBUL, TURKEY
3- DIVISION OF PEDIATRIC GASTROENTEROLOGY, DEPARTMENT OF PEDIATRICS, KOÇ UNIVERSITY SCHOOL OF MEDICINE, ISTANBUL, TURKEY
4- DEPARTMENT OF MEDICAL GENETICS, KOÇ UNIVERSITY SCHOOL OF MEDICINE, ISTANBUL, TURKEY
5- DIVISION OF PEDIATRIC ENDOCRINOLOGY, DEPARTMENT OF PEDIATRICS, MARMARA UNIVERSITY SCHOOL OF MEDICINE, ISTANBUL, TURKEY
 
Introduction:

Aldosterone synthase deficiency is an autosomal recessive disorder, presenting with the severe salt loss in the infantile period. Failure to thrive and inadequate weight gain are the most important symptoms. Hyponatremia, hyperkalemia, decreased aldosterone level and increased plasma renin activity are major findings. While the level of aldosterone is so low to be detected in patients with aldosterone synthase (Corticosterone Methyl Oxidase, CMO) type-1 deficiency, type-2 deficiency can lead to mild clinical findings and mild decreased or normal aldosterone level.

Material and methods:

 

Case:

A seven-month-old girl presented with feeding difficulties, vomiting and inadequate weight gain that had developed from the first month of life. Apart from Familial Mediterranean Fever in her father, family history was unremarkable. Birth weight was 3.3 kg. On physical examination current weight was 4.7 kg (-4.05 SD), height was 61 cm (-2.64 SD), with no hyperpigmentation and genital abnormalities, other findings were insignificant. The serum level of sodium was 129 mEq/L, potassium was 5.1 mEq/L, blood gases were normal, aldosterone level was 55.9 ng/dL (5-90), plasma renin activity was 42.2 pg/mL (2.71-61.8), cortisol was 14 ng/mL (3-21), with a high urine sodium level (70mmol/L, normal<30). Plasma steroid profile, the level of 17-OH progesterone and cortisol were in normal range (0.075 ng/mL and 45.1 ng/mL, respectively), with a high serum corticosterone level (20.1 ng/mL) and low serum aldosterone level (0.035 ng/mL) by Liquid chromatography-tandem mass spectrometry. Clinical exome panel revealed compound heterozygous c.763G>T (p.Glu255Ter) and c.554C>T (Thr185Ile) mutations, and c.21177T>C (p.Val726Ala) and c.2080A>G (p.Met694Val) mutations in the CYP11B2 and MEFV genes, respectively. Thus, diagnosis of aldosterone synthase type-2 deficiency and FMF were ascertained in molecular scale. 

Results:

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Conclusions:

Aldosterone synthase type-2 deficiency and FMF has not been reported in the literature. In the gene pool of conservative populations apart from common diseases, the rate of carriage of rare hereditary diseases have been increasing and just like in the present case dual diagnosis can be observed.