Myhre syndrome
Overview
Myhre syndrome is a very rare inherited disorder with features affecting many systems and functions of the body. It is characterized by retarded growth, mental retardation, bone abnormalities and distinctive facial features.
Symptoms
The list of signs and symptoms mentioned in various sources for Myhre Syndrome includes:
- Prenatal growth deficiency
- Postnatal growth deficiency
- Mental retardation
- Deafness
- Unusual facies
- Underdeveloped upper jaw bone
- Prognathism
- Short eyelids
- Small mouth
- Enlarged muscles
- Decreased joint mobility
- Undescended testes
- Heart anomalies
- Thickened cranium
- Broad ribs
- Large vertebrae
- Flattened vertebrae
- Underdeveloped iliac wings
- Short long bones
- Joint stiffness
Causes
Mutations in the SMAD4 gene cause Myhre syndrome. The SMAD4 gene provides instructions for making a protein involved in transmitting chemical signals from the cell surface to the nucleus. This signaling pathway, called the transforming growth factor beta (TGF-β) pathway, allows the environment outside the cell to affect how the cell produces other proteins. As part of this pathway, the SMAD4 protein interacts with other proteins to control the activity of particular genes. These genes influence many areas of development.