Inborn error of metabolism--zellweger syndrome, how to treat?

No: Unfortunately there is no treatment and children usually die within the first year of life. There are currently ongoing investigation of possible treatments.

Mostly Supportive: Zellweger Syndrome is part of a spectrum of multiple genetic disorders of cell metabolism affecting protein & fatty acid processes. Treatment is mostly supportive. Causes severe birth defects of organ systems, abnormal physical features, mental retardation & more. See link beow for more info: http://rarediseases.info.nih.gov/gard/7917/zellweger-syndrome/resources/1