SNP Shot: Genomic Insights

Refsum disease is a genetic disorder characterized by vision impairment, a lack of smell (anosmia), and various other symptoms.

The vision loss in Refsum disease results from retinitis pigmentosa, an eye condition affecting the retina. The retina, located at the back of the eye, is responsible for light detection. Retinitis pigmentosa causes progressive degeneration of the retina's light-sensing cells, leading to vision loss. Night blindness is usually the initial symptom, often appearing in childhood. The disease gradually impairs peripheral vision over time and can ultimately cause blindness.

While vision loss and anosmia are nearly universal in Refsum disease, other symptoms differ among individuals. Approximately a third of those affected have congenital bone defects in their hands and feet. Later-onset symptoms can include gradual muscle weakness and atrophy, impaired balance and coordination (ataxia), hearing impairment, and dry, flaky skin (ichthyosis). Furthermore, some individuals with Refsum disease experience heart rhythm abnormalities (arrhythmia) and related cardiac issues that can be life-threatening.

Inheritance:

Refsum disease follows an autosomal recessive inheritance pattern. This means that both copies of the responsible gene in each cell must have mutations for the condition to manifest. Individuals with autosomal recessive disorders inherit one mutated gene copy from each parent, who are typically carriers without displaying symptoms themselves.