Acromesomelic dysplasia-Maroteaux type, nine patients with two novel NPR2 variants

J Pediatr Endocrinol Metab. 2021 Jun 24;34(9):1115-1121. doi: 10.1515/jpem-2021-0055. Print 2021 Sep 27.

Abstract

Objectives: Acromesomelic dysplasia, type Maroteaux, is an autosomal recessive skeletal dysplasia caused by biallelic loss of function variations of NPR2, which encodes a cartilage regulator C-type natriuretic peptide receptor B. NPR2 variations impair skeletal growth. It is a rare type of dwarfism characterized by shortening of the middle and distal segments of the limbs with spondylar dysplasia.

Methods: We performed detailed clinical and radiological evaluation and sequence analysis for NPR2.

Results: Herein, we report nine patients from eight families with two novel NPR2 pathogenic variants.

Conclusions: This study describes typical clinical phenotypes of Maroteaux type acromesomelic dysplasia, and enriches the variant spectrum of NPR2 by reporting one nonsense and one missense novel variant. We emphasize the importance of detailed clinical evaluation before genetic testing in diagnosing rare skeletal disorders.

Keywords: NPR2; acromesomelic dysplasia-type Maroteaux; growth; short stature; skeletal disorder.