title: A signal peptide mutation of the arginine vasopressin gene in monozygotic twins.
abstract: Familial neurohypophysial diabetes insipidus (FNDI) is a rare autosomal dominant syndrome stemming from the absence of arginine vasopressin (AVP). More than thirty-five different germline mutations in the arginine vasopressin-neurophysin II gene have been reported. These mutations are either in the signal peptide or scattered throughout the neurophysin II domain. A missense mutation altering alanine at position -1 to either valine or threonine in the signal peptide domain has previously been found in ten unrelated families. In the present report, Brazilian female monozygotic twins with clinically typical central DI in whom biochemical and molecular characterization were carried out are described. Direct mutational analysis by sequencing of the vasopressin gene in germline DNA revealed a heterozygous missense mutation (G-->A) at nucleotide 279, predicting the substitution of alanine by threonine at position -1 of the signal peptide moiety. In summary, we present an extremely rare case of familial central diabetes insipidus in monozygotic Brazilian twins with a seemingly common missense mutation in the AVP gene.
authors.affiliation: Department of Pharmacology, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
authors.forename: Wolfanga L
authors.initials: WL
authors.lastname: Boson
authors.forename: Juliana C
authors.initials: JC
authors.lastname: Sarubi
authors.forename: Catarina B
authors.initials: CB
authors.lastname: d'Alva
authors.forename: Eitan
authors.initials: E
authors.lastname: Friedman
authors.forename: Daniela
authors.initials: D
authors.lastname: Faria
authors.forename: Luiz
authors.initials: L
authors.lastname: De Marco
authors.forename: Bernardo
authors.initials: B
authors.lastname: Wajchenberg
mesh_terms: D000328:Adult; D001127:Arginine Vasopressin / Q000235:genetics*; D020790:Diabetes Insipidus, Neurogenic / Q000235:genetics*; D004200:Diseases in Twins / Q000235:genetics*; D005260:Female; D006801:Humans; D020125:Mutation, Missense; D014430:Twins, Monozygotic
chemical_list: D001127:Arginine Vasopressin