HLD4; Mitochondrial Hsp60 Chaperonopathy (MitCHAP-60)
Inheritance from both parents will result in the disease
Age range at onset:
Typically early infancy (first 3 months)
Specialists you may see:
Onset of symptoms in the first three months of life, characterised by nystagmus, intellectual disability, hypotonia and progressive spastic paraplegia. While head circumference is normal at birth, growth rate will typically slow within the first months of life. Those with this condition can experience seizures and often have feeding difficulties. Survival beyond the first two decades of life is not expected.
More common in consanguineous groups, this condition is caused by mutations in the HSPD1 gene. This gene encodes a mitochondrial protein called Hsp60.
Symptoms are very similar to severe Pelizaeus-Merzbacher Disease; the inclusion of HSPD1-related hypomyelination as a form of Pelizaeus-Merzbacher-like Disease is controversial due to the lack of neuronal involvement.