HYPM
Hypomyelinating Leukodystrophies (HLDs)
Description:
Hypomyelinating leukodystrophies (HLDs) are a group of rare genetic disorders that affect the myelin sheath, the protective layer surrounding nerve cells. Myelin is essential for the proper transmission of electrical signals within the nervous system. In HLDs, the myelin sheath is either underdeveloped (hypomyelination) or absent (demyelination), leading to progressive neurological dysfunction.
Types of HLDs:
There are over 50 known types of HLDs, each caused by a different genetic mutation. Some of the most common types include:
- Adrenoleukodystrophy (ALD)
- Pelizaeus-Merzbacher disease (PMD)
- Metachromatic leukodystrophy (MLD)
- Alexander disease
- Canavan disease
Associated Diseases:
HLDs can be associated with a wide range of systemic and neurological symptoms, depending on the specific type of disorder. Common symptoms include:
- Developmental delays and cognitive impairment
- Muscle weakness and difficulty with coordination
- Sensory disturbances (e.g., vision or hearing loss)
- Spasticity and tremors
- Seizures
- Difficulty swallowing and speech problems
- Behavioral changes
In severe cases, HLDs can lead to paralysis, blindness, and premature death.
Did you Know ?
HLDs are rare, affecting approximately 1 in 150,000 people worldwide. However, the incidence of HLDs can vary significantly depending on the specific type of disorder and the population being studied.
