MON-078 WFS1 Related Disorder in A 4-Month Old Girl

Abstract

Background: Idiopathic early-onset central diabetes insipidus (CDI) may be due to mutations of arginine vasopressin-neurophysin II (AVP-NPII (AVP)) or wolframin (WFS1/2) genes (1). Clinical Case: A 4-month old girl presented to our pediatric endocrinology clinic due to severe polydipsia-polyphagia and polyuria. Plasma and urine glucose and HbA1c were normal and 24h monitoring of urinary output was elevated (4.2ml/kg/h). We proceeded to a modified 5-h water deprivation test followed by 0.1 mcg DDAVP IM. Results were compatible with partial central DI: at 5-hrs weight loss 5%, urine osmolality 155 from 111 at 0΄and 355 mOsm/kg 2hrs after DDAVP administration.Pituitary MRI was normal with presence of posterior pituitary bright spot and normal pituitary stalk.We initiated therapy with oral desmopressin acetate titrated at the dose of 70mcg x 3/day under close clinical and biochemical surveillance. Hyponatremia, with high natriuresis >100 mmol/L and elevated BNP occurred the 3rd day. Fludrocortisone 100 mcg x 2/day controlled natriuresis and supplemental oral NaCl 15% 15ml/day was needed to restore normal electrolytes (2).Marked catch-up growth was observed already at 1 month for height, weight and head circumference. Methods: Whole exome sequencing was performed targeted to a gene panel related to DI, containing AVP gene, WFS1/2 genes and AVPR2/AQP2 genes. Result: Two heterozygous variants were revealed: WFS1:NM_001145853:exon8:c. G997A:p.V333I,WFS1:NM_006005:exon8:c.G997A:p.V333I and WFS1:NM_00114585 3:exon8:c.G1832A:p.R611H,WFS1:NM_006005:exon8:c.G1832A:p.R611H reported as possibly damaging in 1/6 and 4/6 prediction programs respectively. These variants will be checked in both parents to confirm the presumed compound heterozygosity pattern in the child. Conclusion: We present a 4-month old girl with two heterozygous variants of WFS1 gene which may cause early-onset central diabetes insipidus and possibly a WFS1 related disorder (1).Reference:(1) Perrotta S et al. Early-onset central diabetes insipidus is associated with de novo arginine vasopressin-neurophysin II or Wolfram syndrome 1 gene mutations. Eur J Endocrinol. 2015 Apr;172(4):461-72(2) Papadimitriou DT, Spiteri A, Attilakos A, Papadimitriou A. Cerebral Salt Wasting Complicated by Central Diabetes Insipidus and Growth Hormone Deficiency. Indian J Pediatr. 2018 Jul;85(7):580-581