Biochemical diseases are genetic diseases that affect one of the biochemical processes in the human body.
Biochemical processes determine the development and growth of organs and the maintenance of their function. Some of these functions are directly related to nutrition and others are not.
The group of biochemical diseases includes several hundreds of diseases. Most of them are rare (e.g., affecting 1 out of hundreds of thousand individuals) and others are more frequent (e.g. affecting 1 out of 1000 – 10,000 individuals).
One of the most frequent biochemical disease is Phenylketonuria which occurs in one out of 10,000 newborns. Every year in BC, 2-3 children are born with PKU. PKU leads to severe intellectual impairment if untreated, but with early recognition of this disorder and early dietary treatment, this can completely be avoided. This allows children with PKU to have a completely normal development.
Biochemical diseases as a group are not recognizable by a common clinical trait or a common pattern of organ involvement. Depending on the particular defect, biochemical diseases may affect different organs and organ systems (liver, heart, kidney, muscle, brain and others) as single organs or as multi-organ disease.
The development of the disease may vary from an acute neonatal onset and early lethal outcome to chronic and slowly progressing. Mostly these diseases occur in infancy and early childhood, but sometimes they occur later in life and even in adulthood.
Most biochemical diseases affect the brain and a number of conditions lead to mental retardation, developmental delay, behavioural problems, neurologic handicap, and/or epilepsy. Treatment of nervous system manifestations is the greatest challenge.
Every year a number of new diseases are recognized and new treatment strategies are developed. Sometimes problems arising with a single patient lead to new research projects and findings that benefit patients with rare biochemical diseases as well as patients with other more frequent conditions.