What is Omodysplasia?
Omodysplasia is a rare genetic syndrome defined by its unique facial features and severely shortened limbs. It is a skeletal dysplasia disorder. There are just 40 cases of the syndrome reported worldwide.
Syndrome Synonyms:
Micromelic Dysplasia, Congenital, with Dislocation of Radius; Omodysplasia
What gene changes cause Omodysplasia?
There are two forms of the syndrome. One is inherited in an autosomal dominant pattern with mutations in the FZD2 gene, another is an autosomal recessive pattern with mutations in the GPC6 gene.
Autosomal recessive inheritance means an affected individual receives one copy of a mutated gene from each of their parents, giving them two copies of a mutated gene. Parents, who carry only one copy of the gene mutation will not generally show any symptoms but have a 25% chance of passing the copies of the gene mutations onto each of their children.
In the case of autosomal dominant inheritance, just one parent is the carrier of the gene mutation, and they have a 50% chance of passing it on to each of their children. Syndromes inherited in an autosomal dominant inheritance are caused by just one copy of the gene mutation.
What are the main symptoms of Omodysplasia?
The main symptoms of the syndrome vary according to the type of the syndrome.
- The autosomal recessive form of the syndrome has severe shortening of the upper and lower limbs as a main symptom, as well as micromelic dwarfism.
The autosomal dominant form of the syndrome presents with a normal stature and only the upper limbs are shortened. - The unique facial features of the syndrome include frontal bossing, a depressed nasal bridge, a short nose, and a long philtrum (the space between the bottom of the nose and the top of the upper lip).
- Affected individuals may also have issues with movement of their elbows and knees.
Possible clinical traits/features:
Atrial septal defect, Axillary pterygium, Blepharophimosis, Aplasia/Hypoplasia of the radius, Abnormality of femur morphology, Abnormality of the metaphysis, Abnormality of the humerus, Wide nasal bridge, Popliteal pterygium, Autosomal recessive inheritance, Short neck, Short humerus, Hernia, Short tibia, Depressed nasal bridge, Cognitive impairment, Hemangioma, Frontal bossing, Umbilical hernia, Ventricular septal defect, Pulmonary artery stenosis, Anterolateral radial head dislocation, Limited elbow flexion/extension, Limited knee flexion/extension, Hypoplastic distal humeri, Increased fibular diameter, Flat face, Rhizomelia, Micrognathia, Micromelia, Increased nuchal translucency, Limited elbow extension, Limited elbow flexion, Limited hip movement, Limited knee extension, Limited knee flexion, Long philtrum, Low-set, posteriorly rotated ears, Short nose, Anteverted nares, Fibular hypoplasia, Malformation of the heart and great vessels, Epicanthus, Cryptorchidism, Craniosynostosis, Malar flattening, Disproportionate short stature.
How is it diagnosed?
To find out if someone has a diagnosis of Omodysplasia, it is important to have a consultation and evaluation with a clinical genetic specialist. Specialists may also suggest specific genetic testing or other types of tests to help reach a diagnosis. FDNA’s AI technology can help speed up the diagnostic process by analyzing facial features and other health information.
