Group 2 peroxisomal disorders are a group of rare genetic disorders that affect the peroxisomes, which are small organelles within cells that are responsible for various metabolic functions. These disorders are classified into 3 subgroups depending on which enzyme or protein is affected. Group 2 includes disorders that affect enzymes involved in the breakdown of very long-chain fatty acids.
There are several different types of group 2 peroxisomal disorders, including:
X-ALD is the most common of these disorders, affecting about 1 in 20,000 people. It primarily affects boys and can cause progressive neurological symptoms such as difficulty walking, seizures, and loss of vision. Zellweger syndrome is the most severe form of group 2 peroxisomal disorders and typically leads to death in early infancy. NALD and infantile Refsum disease are milder forms of Zellweger syndrome, with symptoms that may include hearing and vision loss, developmental delays, and liver dysfunction. Acyl-CoA oxidase deficiency is a rare disorder that can cause muscle weakness, developmental delay, and vision problems.
Diagnosis of group 2 peroxisomal disorders typically involves genetic testing to look for mutations in the genes associated with these disorders. Treatment is generally supportive and focused on managing symptoms. For example, in X-ALD, treatment may involve medications to manage seizures and physical therapy to help maintain mobility.
Overall, while group 2 peroxisomal disorders are rare, they can have devastating effects on those who are affected. Understanding these disorders and their symptoms can help with early diagnosis and management of symptoms.