A low protein diet is the gold standard in the management of HT. People with HT1 follow a low protein diet in combination with a medication prescribed to them by their doctor. In a person without HT, Tyr would be broken down into metabolites and then into substances the body can use, by enzymes, including FAH and TAT. HT1 and HT2 are simply enzyme deficiencies at different points in the Tyr breakdown process. People with HT2 cannot break Tyr down into metabolites, and people with HT1 cannot break down metabolites into useful substances. This means Tyr and metabolites can build up in the body to high levels. In HT1, a buildup of metabolites and Tyr can cause serious damage to the liver, kidneys and brain, and increase the risk of liver cancer. In HT2, crystals of Tyr can build up in the eyes and skin, causing painful inflammation.
Medication works in people with HT1 by stopping the breakdown of Tyr into harmful metabolites, but it doesn’t lower the levels of Tyr. This medication is not effective in people with HT2 because their bodies can’t break Tyr down into metabolites.
A low protein diet means people with HT can stay healthy and be the best version of themselves.