Infantile refsum disease

Infantile Refsum Disease (IRD) is a rare genetic disorder that affects multiple systems of the body. It is classified as a peroxisomal disorder due to the malfunction of peroxisomes, specialized structures within cells that play a key role in the breakdown and synthesis of various critical substances.

Etiology

IRD is caused by mutations in the PEX1, PEX6, or PEX26 genes. These genes are responsible for the formation of peroxisomes. Mutations in these genes disrupt the normal function of peroxisomes, leading to the accumulation of certain toxic substances in the body, particularly very long-chain fatty acids (VLCFAs) and phytanic acid.

Symptoms

The symptoms of IRD typically appear in infancy or early childhood. They may include retinitis pigmentosa, a condition that causes progressive vision loss, and sensorineural hearing loss. Other symptoms may include developmental delay, intellectual disability, poor growth, liver dysfunction, and distinctive facial features.

Diagnosis

Diagnosis of IRD is based on the clinical symptoms, biochemical testing showing elevated levels of VLCFAs and phytanic acid, and genetic testing confirming mutations in the PEX1, PEX6, or PEX26 genes.

Treatment

There is currently no cure for IRD. Treatment is supportive and aims to manage the symptoms. This may include dietary restrictions to limit the intake of phytanic acid, physical therapy to manage mobility issues, and regular monitoring of vision and hearing.

Prognosis

The prognosis for individuals with IRD varies. Some individuals may have a relatively mild course with survival into adulthood, while others may have severe, life-threatening complications in early childhood.

See also

• Zellweger spectrum
• Peroxisomal biogenesis disorder
• Genetic disorder
• Retinitis pigmentosa
• Sensorineural hearing loss

NIH genetic and rare disease info

• NIH info on Infantile refsum disease

Infantile refsum disease is a rare disease.