5th February 2024

Peroxisomal disorders

Peroxisomes are cytoplasmic organelles that play a central role in the catabolism of very long-chain fatty acids and other compounds via beta-oxidation, essential in the biosynthesis of crucial cellular membrane constituents, cholesterol and bile acids. 

Zellweger’s syndrome

It is an autosomal recessive condition caused by gene mutations involved in peroxisome function.

It is considered a collective spectrum of disease, with the most severe form referred to as Zellweger syndrome. Its intermediate form is known as neonatal adrenoleukodystrophy, and infantile Refsum disease is milder.

• Symptoms: neurological deficits, progressive liver and renal dysfunction, optic nerve hypoplasia, pigmentary retinopathy, hypotonia, developmental delay, failure to thrive, flat brows

Refsum’s disease

It is an autosomal recessive condition. It is caused by a mutation in the gene that transports phytanoyl-CoA hydroxylase enzymes into peroxisomal compartments. Phytanic acid cannot be broken down and accumulates in the cell. Patients usually develop normally, and symptoms start at 10-20 years old, including nyctalopia, retinitis pigmentosa, cerebellar ataxia, anosmia, ichthyosis, and hearing impairment.

Diagnosis is made with raised phytanic acid in blood, low pristanic acid and molecular genetic diagnosis.

Treatment is done by minimising intake of phytanic acid and plasmapheresis.