Metatropic Dysplasia of Nonlethal Variant in a Chinese Child - A Case Report.

Michele A Tchio Tchoumba,Yan Bai,Xianying Yu,Runming Jin,Musa Male

doi:10.1111/os.12546

Abstract

Metatropic dysplasia (MD), is a rare skeletal dysplasia occurring predominantly in infants characterized by a distinctive long torso and short limbs; it is as a result of mutations in the TRPV4 gene. However, a clear distinction between various forms of skeletal dysplasias caused by the transient receptor potential vanilloid 4 (TRPV4) gene is difficult but could be achieved by a combination of gene sequencing, medical and radiological criteria. We hereby report a case of a 14‐month old girl who presented with an abnormal stature. The diagnosis of nonlethal MD was confirmed by X‐ray with dumbbell‐shaped long bones, platyspondyly, and delayed carpal ossification, as well as broadened pelvis with marginally widened ilia, epiphyseal plates, and slightly flattened acetabula. Furthermore, gene sequencing confirmed gene mutation on exon 15 of the TRPV4 gene with a heterozygous missense mutation (c.2396C > T), but no mutation was present in her parents. Our findings recorded metatropic dysplasia with the c.2396C > T mutation in the TRPV4 gene in China. This mutation caused changes in amino acid of TRPV4, which can induce growth retardation in children.

Highlights

Metatropic dysplasia (MD) or changeable dysplasia has been characterized by progressive spinal changes observed from the neonatal period in childhood with a wide severity range both clinically and radiographically[1,2]
We reported a 14-month old child with clinical and radiological features of MD with mutation of the transient receptor potential vanilloid 4 (TRPV4) gene
It is classified among various forms of skeletal dysplasias caused by TRPV4 gene impairment which incorporates familial digital arthropathy-brachydactyly, autosomal dominant brachyolmia, spondylometaphyseal dysplasia-Kozlowski type (SMDK), spondyloepiphyseal dysplasia-Maroteaux type (SEDM), parastremmatic dysplasia, and metatropic dysplasia[3,5]

Summary

Introduction

Metatropic dysplasia (MD) or changeable dysplasia has been characterized by progressive spinal changes observed from the neonatal period in childhood with a wide severity range both clinically and radiographically[1,2]. A 14-month old female child was brought to the Pediatric Department of Union Hospital by her parents because of short limbs. She was born with a healthy and uneventful birth history, as stated by her parents. Communication and locomotive abilities appeared to be normal considering her current age of 14 months.

A CASE REPORT OF NON-LETHAL METATROPIC DYSPLASIA

Findings

Discussion