Type I Tyrosinemias is a rare inherited metabolic disorder that affects the way the body breaks down the amino acid tyrosine. It is caused by a deficiency of the enzyme fumarylacetoacetate hydrolase (FAH), which is necessary for the complete breakdown of tyrosine.
In normal metabolism, tyrosine is broken down into several byproducts, including fumarylacetoacetate, through a series of enzymatic reactions. However, in individuals with Type I Tyrosinemias, the lack of FAH causes fumarylacetoacetate to build up in the body. This can lead to the accumulation of toxic substances, such as succinylacetone, which can cause serious damage to the liver and kidneys, as well as other organs and tissues.
Symptoms of Type I Tyrosinemias can vary in severity and may appear in infancy or early childhood. They can include failure to thrive, poor weight gain, liver enlargement (hepatomegaly), developmental delays, and a characteristic cabbage-like odor in the urine. Without prompt diagnosis and treatment, the condition can lead to liver failure and death in severe cases.
Treatment for Type I Tyrosinemias typically involves a strict low-tyrosine diet, which restricts the intake of tyrosine and phenylalanine (another amino acid that can be converted to tyrosine). This helps to reduce the buildup of toxic byproducts. In some cases, medication may be used to further lower the levels of toxic substances. Liver transplantation may also be considered for individuals with severe liver damage.
Early diagnosis and lifelong management are crucial for individuals with Type I Tyrosinemias to prevent serious complications and improve outcomes. Regular monitoring and adherence to a specialized diet are essential
