Occipital Horn Syndrome (OHS) is a rare genetic disorder affecting connective tissue, skeleton, and nervous system.
Here's a breakdown of what that entails:
Understanding Occipital Horn Syndrome
Occipital Horn Syndrome (OHS) is a milder variant of Ehlers-Danlos syndrome type IX, also known as X-linked cutis laxa. It is caused by mutations in the ATP7A gene, which is responsible for copper transport in the body.
Key Characteristics:
- Occipital Horns: This is the defining characteristic. These are wedge-shaped calcium deposits that develop at the base of the skull. They can usually be felt under the skin.
- Connective Tissue Problems: This can lead to:
- Loose joints (hypermobility)
- Soft, doughy skin
- Hernias
- Vascular problems in some individuals.
- Skeletal Abnormalities: Besides the occipital horns, other skeletal issues can occur.
- Neurological Issues:
- Dysautonomia: This refers to dysfunction of the autonomic nervous system, which controls involuntary functions like heart rate, blood pressure, sweating, and digestion. This can manifest as problems with bowel and bladder control, temperature regulation, and blood pressure.
- Bladder Diverticula: Outpouchings in the bladder wall are common.
- Other Potential Features: These may include coarse facial features, intellectual disability (variable), and hernias.
Genetics
OHS is X-linked recessive. This means that the ATP7A gene is located on the X chromosome. Males, having only one X chromosome, are typically more severely affected. Females, with two X chromosomes, may be carriers or may exhibit milder symptoms due to X-inactivation (where one X chromosome is randomly inactivated in each cell).
Diagnosis
Diagnosis is based on clinical findings (presence of occipital horns and other characteristic features) and can be confirmed by genetic testing to identify mutations in the ATP7A gene.
Management
There is no cure for Occipital Horn Syndrome. Management focuses on addressing specific symptoms and complications:
- Physical therapy to improve joint stability and muscle strength.
- Occupational therapy to help with daily living skills.
- Medical management of dysautonomia symptoms.
- Surgical repair of hernias or bladder diverticula if necessary.
In Summary
Occipital Horn Syndrome is a complex genetic condition with a variety of manifestations. The presence of occipital horns, along with connective tissue, skeletal, and neurological problems, are key features. Management is supportive and aims to improve the individual's quality of life.
