Objective: Idiopathic early-onset central diabetes insipidus (CDI) might be due to mutations of arginine vasopressin-neurophysin II (AVP-NPII (AVP)) or wolframin (WFS1) genes. Design and methods: Sequencing of AVP and WFS1 genes was performed in nine children with CDI, aged between 9 and 68 months, and negative family history for polyuria and polydipsia. Results: Two patients carried amutation in the AVP gene: a heterozygous G-to-T transition at nucleotide position 322 of exon 2 (c.322G>T) resulting in a stop codon at position 108 (p.Glu108X), and a novel deletion fromnucleotide 52 to 54 (c.52-54delTCC) producing a deletion of a serine at position 18 (p.Ser18del) of the AVP pre-prohormone signal peptide. A third patient carried two heterozygous mutations in the WFS1 gene localized on different alleles. The first change was A-to-G transition at nucleotide 997 in exon 8 (c.997A>G), resulting in a valine residue at position 333 in place of isoleucine (p.Ile333Val). The second novel mutation was a 3 bp insertion in exon 8, c.2392-2393insACG causing the addition of an aspartate residue at position 797 and the maintenance of the correct open reading frame (p. Asp797-Val798insAsp). While similar WFS1 protein levels were detected in fibroblasts from healthy subjects and from the patient and his parents, a major sensitivity to staurosporine-induced apoptosis was observed in the patient fibroblasts as well as in patients with Wolfram syndrome. Conclusions: Early-onset CDI is associated with de novo mutations of the AVP gene and with hereditary WFS1 gene changes. These findings have valuable implications for management and genetic counseling.
ASJC Scopus subject areas
- Endocrinology, Diabetes and Metabolism