Question: How many people are affected by Refsum disease ?
Answer: The prevalence of Refsum disease is unknown, although the condition is thought to be uncommon.
Source: GHR

Question: What are the genetic changes related to Refsum disease ?
Answer: More than 90 percent of all cases of Refsum disease result from mutations in the PHYH gene. The remaining cases are caused by mutations in a gene called PEX7. The signs and symptoms of Refsum disease result from the abnormal buildup of a type of fatty acid called phytanic acid. This substance is obtained from the diet, particularly from beef and dairy products. It is normally broken down through a process called alpha-oxidation, which occurs in cell structures called peroxisomes. These sac-like compartments contain enzymes that process many different substances, such as fatty acids and certain toxic compounds. Mutations in either the PHYH or PEX7 gene disrupt the usual functions of peroxisomes, including the breakdown of phytanic acid. As a result, this substance builds up in the body's tissues. The accumulation of phytanic acid is toxic to cells, although it is unclear how an excess of this substance affects vision and smell and causes the other specific features of Refsum disease.
Source: GHR

Question: Is Refsum disease inherited ?
Answer: This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition.
Source: GHR

Question: What are the treatments for Refsum disease ?
Answer: These resources address the diagnosis or management of Refsum disease: - Gene Review: Gene Review: Refsum Disease - Gene Review: Gene Review: Retinitis Pigmentosa Overview - Genetic Testing Registry: Phytanic acid storage disease - MedlinePlus Encyclopedia: Retinitis Pigmentosa These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care
Source: GHR