Identification of Mutations of the Arginine Vasopressin-Neurophysin II Gene in Two Kindreds with Familial Central Diabetes Insipidus

Familial central diabetes insipidus is transmitted as an autosomal dominant trait with almost complete penetrance. Twenty-three different mutations of the arginine vasopressin-neurophysin II gene have been reported to date, located within the signal peptide-, the arginine vasopressin-, or the neurophysin II-coding region. In the present study two kindreds with familial central diabetes insipidus were examined. The entire coding region of the arginine vasopressin-neurophysin II gene of one affected subject of each family was amplified by PCR and subcloned into a pUC 18 plasmid, and six positive clones were sequenced. After identification of the mutation, direct sequencing was performed on the respective sequence of family members and 28 healthy control subjects. In family A, a missense mutation (C→T) at nucleotide position 280 was detected, predicting the substitution of alanine by valine at position −1 of the signal peptide. All affected subjects were heterozygote for the mutation, whereas none of the unaffected family members or control subjects displayed the mutant sequence. In family B, a missense mutation within the neurophysin II-coding sequence was identified (nucleotide 1757, G→C), predicting the substitution of glycine by arginine at position 23. Again, affected family members were found to be heterozygote for the mutation, which was not observed in unaffected family members or in control subjects. Although the mutation of family A was recently described in 3 other kindreds as well, the mutation within the neurophysin II-coding region represents a novel mutation of the AVP-NP II gene.

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Early-onset central diabetes insipidus is associated with de novo arginine vasopressin–neurophysin II or Wolfram syndrome 1 gene mutations

Acta Endocrinologica ◽

10.1530/eje-14-0942 ◽

2015 ◽

Vol 172 (4) ◽

pp. 461-472 ◽

Cited By ~ 15

Author(s):

Silverio Perrotta ◽

Natascia Di Iorgi ◽

Fulvio Della Ragione ◽

Saverio Scianguetta ◽

Adriana Borriello ◽

...

Keyword(s):

Diabetes Insipidus ◽

Arginine Vasopressin ◽

Early Onset ◽

De Novo ◽

Novel Mutation ◽

Wolfram Syndrome ◽

Central Diabetes Insipidus ◽

Nucleotide Position ◽

Exon 2 ◽

Neurophysin Ii

ObjectiveIdiopathic 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 methodsSequencing 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.ResultsTwo patients carried a mutation 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 from nucleotide 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.ConclusionsEarly-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.

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