Related Experiment Video
Updated: Aug 30, 2026

Navigating MARRVEL, a Web-Based Tool that Integrates Human Genomics and Model Organism Genetics Information
Published on: August 15, 2019
Metatropic dysplasia lethal variants
Christine M Hall1, Nursel H Elçioglu
1Department of Radiology, Great Ormond Street Hospital for Children NHS Trust, London, WCIN 3JH, UK. hallc@gosh.nhs.uk
Background:
The metatropic dysplasia group includes fibrochondrogenesis, Schneckenbecken dysplasia and metatropic dysplasia (various forms). The overlapping features of this group with other dysplasias may cause diagnostic confusion, particularly in perinatal lethal cases.
Objective:
To attempt to classify the radiological findings of the presented eight sporadic cases based on a broad review of the perinatally lethal metatropic group of conditions and to discuss some overlapping features in the light of current knowledge.
Results:
The first four cases are of recognised conditions, namely lethal metatropic dysplasia (Type 2) or hyperchondrogenesis, lethal hyperplastic metatropic dysplasia (Type 1) and fibrochondrogenesis. The remaining four cases cannot be categorised accurately and are different from each other but with some features of the metatropic group of dysplasias.
Conclusions:
The dysplasias within the metatropic dysplasia group are phenotypically distinct from many forms of chondrodysplasia but the pathogenesis still remains poorly understood from the morphological and molecular perspectives. Chondro-osseous morphology might be helpful in all lethal cases especially in our last four cases.
Related Concept Videos
Lethal Alleles
Lucien Cuénot discovered lethal alleles in 1905 while studying the inheritance of coat color in mice. The agouti gene is responsible for the color of the coat in mice. This gene codes for an agouti-signaling protein, which is responsible for melanin distribution in mammals. The wild-type allele gives rise to gray-brown coat color in mice, while the mutant allele gives rise to yellow coat color. In addition to coat color, the agouti gene is associated with the yellow...
Mutations
Pharmacogenetics of Drug Targets: β₂-Adrenergic Receptors, Apo E, Thymidylate Synthase
Point and Frameshift Mutations

