Article,

An Activating Deletion Variant in the Submembrane Region of Natriuretic Peptide Receptor-B Causes Tall Stature

, , , , , , , , , and .
J Clin Endocrinol Metab, 105 (7): 2354-66 (2020)Lauffer, Peter Miranda-Laferte, Erick van Duyvenvoorde, Hermine A van Haeringen, Arie Werner, Franziska Boudin, Eveline Schmidt, Hannes Mueller, Thomas D Kuhn, Michaela van der Kaay, Danielle C M eng Case Reports Research Support, Non-U.S. Gov't 2020/04/14 J Clin Endocrinol Metab. 2020 Jul 1;105(7):2354-66. doi: 10.1210/clinem/dgaa190..
DOI: 10.1210/clinem/dgaa190

Abstract

CONTEXT: C-type natriuretic peptide (CNP) is critically involved in endochondral bone growth. Variants in the genes encoding CNP or its cyclic guanosine monophosphate (cGMP)-forming receptor (natriuretic peptide receptor-B NPR-B, gene NPR2) cause monogenic growth disorders. Here we describe a novel gain-of-function variant of NPR-B associated with tall stature and macrodactyly of the great toes (epiphyseal chondrodysplasia, Miura type). DESIGN: History and clinical characteristics of 3 family members were collected. NPR2 was selected for sequencing. Skin fibroblasts and transfected HEK-293 cells were used to compare mutant versus wild-type NPR-B activities. Homology modeling was applied to understand the molecular consequences of the variant. RESULTS: Mother's height was +2.77 standard deviation scores (SDS). The heights of her 2 daughters were +1.96 SDS at 7 years and +1.30 SDS at 4 years of age. Skeletal surveys showed macrodactyly of the great toes and pseudo-epiphyses of the mid- and proximal phalanges. Sequencing identified a novel heterozygous variant c.1444_1449delATGCTG in exon 8 of NPR2, predicted to result in deletion of 2 amino acids Met482-Leu483 within the submembrane region of NPR-B. In proband's skin fibroblasts, basal cGMP levels and CNP-stimulated cGMP production were markedly increased compared with controls. Consistently, assays with transfected HEK-293 cells showed markedly augmented baseline and ligand-dependent activity of mutant NPR-B. CONCLUSIONS: We report the second activating variant within the intracellular submembrane region of NPR-B resulting in tall stature and macrodactyly. Our functional and modeling studies suggest that this domain plays a critical role in the baseline conformation and ligand-dependent structural rearrangement of NPR-B required for cGMP production.

Tags

Users

  • @tdmueller
  • @jvsi_all

Comments and Reviews