Identification and Functional Characterization of Two Novel NPR2 Mutations in Japanese Patients With Short Stature

N Amano, T Mukai, Y Ito, S Narumi… - The Journal of …, 2014 - academic.oup.com
N Amano, T Mukai, Y Ito, S Narumi, T Tanaka, S Yokoya, T Ogata, T Hasegawa
The Journal of Clinical Endocrinology & Metabolism, 2014academic.oup.com
Context: C-type natriuretic peptide-natriuretic peptide receptor B (NPR-B) signaling is critical
for endochondral ossification, which is responsible for longitudinal growth in limbs and
vertebrae. Biallelic NPR2 mutations cause acromesomelic dysplasia, type Maroteaux, which
is bone dysplasia characterized by severe short stature and short limbs. A monoallelic NPR2
mutation has been suggested to mildly impair long bone growth. Objective: The goal of this
study was to identify and characterize NPR2 mutations among Japanese patients with short …
Context
C-type natriuretic peptide-natriuretic peptide receptor B (NPR-B) signaling is critical for endochondral ossification, which is responsible for longitudinal growth in limbs and vertebrae. Biallelic NPR2 mutations cause acromesomelic dysplasia, type Maroteaux, which is bone dysplasia characterized by severe short stature and short limbs. A monoallelic NPR2 mutation has been suggested to mildly impair long bone growth.
Objective
The goal of this study was to identify and characterize NPR2 mutations among Japanese patients with short stature.
Subjects and Methods
We enrolled 101 unrelated Japanese patients with short stature. NPR2 and NPPC were sequenced, and the identified variants were characterized in vitro.
Results
In two subjects, we identified two novel heterozygous NPR2 mutations (R110C and Q417E) causing a loss of C-type natriuretic peptide-dependent cGMP generation capacities and having dominant-negative effects. R110C was defective in trafficking from the endoplasmic reticulum to the Golgi apparatus. In contrast, Q417E showed clear cell surface expression.
Conclusions
We identified heterozygous NPR2 mutations in 2% of Japanese patients with short stature. Our in vitro findings indicate that NPR2 mutations have a dominant negative effect, and their dominant-negative mechanisms vary corresponding to the molecular pathogenesis of the mutations.
Oxford University Press