A novel polymorphism in the coding region of the vasopressin type 2 receptor gene.
Nephrogenic diabetes insipidus (NDI) is a rare disease characterized by renal inability to respond properly to arginine vasopressin due to mutations in the vasopressin type 2 receptor (V2(R)) gene in affected kindreds. In most kindreds thus far reported, the mode of inheritance follows an X chromosome-linked recessive pattern although autosomal-dominant and autosomal-recessive modes of inheritance have also been described. Studies demonstrating mutations in the V2(R) gene in affected kindreds that modify the receptor structure, resulting in a dys- or nonfunctional receptor have been described, but phenotypically indistinguishable NDI patients with a structurally normal V2(R) gene have also been reported. In the present study, we analyzed exon 3 of the V2(R) gene in 20 unrelated individuals by direct sequencing. A C-->T alteration in the third position of codon 331 (AGC-->AGT), which did not alter the encoded amino acid, was found in nine individuals, including two unrelated patients with NDI. Taken together, these observations emphasize the molecular heterogeneity of a phenotypically homogeneous syndrome.
Rocha
J L
JL
Departamento de Farmacología, Universidade Federal de Minas Cerais, Belo Horizonte, Brasil.
Moreira
A C
AC
Friedman
E
E
Liberman
B
B
Silva
B C
BC
De-Marco
L
L
D018500:Diabetes Insipidus, Nephrogenic / Q000235:genetics*; D006801:Humans; D011110:Polymorphism, Genetic / Q000235:genetics*; D017483:Receptors, Vasopressin / Q000235:genetics*
D017483:Receptors, Vasopressin