Novel Mutations Found in the AVP-NPII Gene

Alejandro García-Castaño, Leire Madariaga, Gustavo Pérez de Nanclares, Amaia Vela, Itxaso Rica, Sonia Gaztambide, Rosa Martínez, Idoia Martinez de LaPiscina, Inés Urrutia, Anibal Aguayo, Olaia Velasco, Familial Neurohypophyseal Diabetes Insipidus Spanish Working Group, Luis Castaño
The Journal of Clinical Endocrinology & Metabolism, Volume 105, Issue 4, April 2020, Pages 1112–1118
https://doi.org/10.1210/clinem/dgaa069

Abstract

Context

Familial neurohypophyseal diabetes insipidus is a rare disease produced by a deficiency in the secretion of antidiuretic hormone and is caused by mutations in the arginine vasopressin gene.

Objective

Clinical, biochemical, and genetic characterization of a group of patients clinically diagnosed with familial neurohypophyseal diabetes insipidus, 1 of the largest cohorts of patients with protein neurophysin II (AVP-NPII) gene alterations studied so far.

Design

The AVP-NPII gene was screened for mutations by PCR followed by direct Sanger sequencing in 15 different unrelated families from Spain.

Results

The 15 probands presented with polyuria and polydipsia as the most important symptoms at the time of diagnosis. In these patients, the disease was diagnosed at a median of 6 years of age. We observed 11 likely pathogenic variants. Importantly, 4 of the AVP-NPII variants were novel (p.(Tyr21Cys), p.(Gly45Ser), p.(Cys75Tyr), p.(Gly88Cys)).

Conclusions

Cytotoxicity seems to be due to consequences common to all the variants found in our cohort, which are not able to fold correctly and pass the quality control of the ER. In concordance, we found autosomal dominant familial neurohypophyseal diabetes insipidus in the 15 families studied.

You may also like...