NEWBORN SCREENING FACT SHEET FAH Deficiency (Tyrosinemia Type 1) What is it? 1) Diarrhea and bloody stools. This condition is one type of amino acid 2) Vomiting. disorder. People with tyrosinemia 1 have 3) Poor weight gain. problems breaking down an amino acid called 4) Extreme sleepiness. tyrosine from the food they eat. If not treated, 5) Irritability. the condition causes severe liver disease and 6) Cabbage-like odor to skin or urine. other serious health problems. Liver problems are common. They can lead to: What causes it? 1) Enlarged liver. In order for the body to use protein from the 2) Yellowing of the skin. food we eat, it is broken down into smaller parts 3) Tendency to bleed and bruise easily. called amino acids. Special enzymes then make 4) Swelling of the legs and abdomen. changes to the amino acids so the body can use them. Kidney problems also happen and can lead to: 1) Rickets, a bone-thinning condition. Tyrosinemia 1 occurs when an enzyme, called 2) Delays in walking. fumarylacetoacetase (FAH), is either missing or not working properly. When FAH is not Without prompt and careful treatment, babies with working, it cannot break down tyrosine. severe liver and kidney problems usually die. Tyrosine and other harmful substances then build up in the blood. One of these substances is Some babies also have episodes that include: called succinylacetone. When it builds up in the 1) Pain or weakness, especially in the legs. blood, it causes serious liver and kidney damage. 2) Breathing problems. It may also cause episodes of weakness or pain. 3) Rapid heartbeat. 4) Seizures. If tyrosinemia 1 is not treated, what problems 5) Coma, sometimes leading to death. occur? The symptoms can vary a great deal from person Tyrosinemia 1 in Children (Chronic Form) to person. There are two types of tyrosinemia 1. Children with the chronic form usually start The more common form happens in infants. The having symptoms after 2 months of age. Some of less common form is seen in older children and the first signs may be trouble gaining weight and adults. episodes of vomiting and diarrhea. Over time, the condition can cause liver, kidney and nerve Tyrosinemia 1 in Infants problems. Babies usually have symptoms within the first few months of life. Some of the first symptoms may be: FAH 1 of 5 May 2008 Liver Medication If the condition is not treated, a rare type of A medication called nitisinone (Orfadin®) is liver scarring called nodular cirrhosis used to prevent liver and kidney damage. It also can happen. This gets worse over time and can stops the neurologic crises. The medication also lead to liver failure. If not treated, many may lessen the risk for liver cancer. Your child children develop liver failure or liver cancer should start talking nitisinone as soon as before age 10. Medication, when started early, possible. Your doctor will need to write a can prevent liver failure in most children. prescription for this medication. Kidney Nitisinone will increase the level of tyrosine in Serious kidney problems can occur in untreated your child’s blood. So, a low-tyrosine diet is a children. When the kidneys are not working very important part of treatment. properly, episodes of vomiting, weakness and fever can happen. Rickets, a bone-thinning Vitamin D sometimes is used to treat children condition, may happen in children with kidney who have rickets. damage. Medication can prevent kidney problems in most children. Do not take any medication without talking with your doctor. Neurologic Crises Some children have episodes of weakness, pain Medical Formula or numbness in their arms, legs or other parts The special medical formula gives babies and of the body. Breathing problems and rapid children the nutrients and protein they need heartbeat may also happen. Some children have while helping keep their tyrosine levels within seizures that can lead to coma. Medication can a safe range. Your metabolic doctor and stop episodes of neurologic crisis in most dietician will tell you what type of formula is children. best and how much to use. Other Low-Tyrosine Diet A small number of children have had heart The diet is made up of foods that are very low problems. Some have had high blood pressure. in tyrosine and another amino acid called phenylalanine. This means your child will need What is the treatment for tyrosinemia 1? to limit foods such as cow’s milk and regular Your baby’s doctor will work with a metabolic formula. He or she will need to avoid meat, doctor and dietician to care for your child. eggs and cheese. Regular flour, dried beans, Lifelong treatment usually is needed to prevent nuts and peanut butter contain these amino liver and kidney problems. acids also must be limited. Treatment consists of medication and a diet low Many vegetables and fruits have only small in tyrosine. The low-tyrosine diet is made up of amounts of phenylalanine and tyrosine and can a special medical formula and carefully chosen be eaten regularly in carefully measured foods. You must start the treatment as soon as amounts. you know your child has the condition. There are other medical foods such as special The following are treatments often flours, pastas and rice that are made especially recommended for children with tyrosinemia 1: for people with tyrosinemia 1. Some states offer help with payment, or require private FAH 2 of 5 May 2008 insurance coverage for formula and other prevented. Children who are treated usually special medical foods. have normal growth and intelligence. Your metabolic doctor and dietician will decide If treatment is not started right away, children on the best food plan for your child. The exact may have some liver or kidney damage. plan will depend on many things, such as your Rickets already may be present and need to be child’s age, weight and general health and how treated. Delays in growth and development also well the medication is working. Your dietician may be present. The effects of delayed will fine-tune your child’s diet over time. treatment vary from child to child. Blood, Urine and Other Tests What causes the FAH enzyme to be absent Your child will have regular blood and urine or not working correctly? tests to check: Genes tell the body to make various enzymes. 1) Amino acid levels. People with tyrosinemia 1 have a pair of genes 2) Amount of succinylacetone. that do not work correctly. Because of the 3) Nitisinone level. changes in this pair of genes, the FAH enzyme 4) Liver and kidney function. does not work properly or is not made at all. These tests help your doctor and dietician How is tyrosinemia 1 inherited? figure out whether any changes to the The condition is inherited in an autosomal medication or diet are needed. recessive manner. It affects both boys and girls equally. Some experts suggest that children with tyrosinemia 1 have a CT or MRI scan of their Everyone has a pair of genes that make the liver once a year to check for scarring or FAH enzyme. In children with tyrosinemia 1, cancer. neither of these genes works correctly. These children inherit one nonworking gene for the Liver Transplantation condition from each parent. Before nitisinone was available, liver transplantation was one of the main treatments Parents of children with tyrosinemia 1 rarely for tyrosinemia 1. Now nitisinone can prevent have the condition themselves. Instead, each or reverse many of the liver problems. More parent has a single non-working gene for the time is needed to see if this medication can condition. They are called carriers. Carriers do prevent liver cancer. For most children, not have the condition because the other gene nitisinone will delay, and hopefully prevent, the of this pair is working correctly. need for liver transplant. When both parents are carriers, there is a 25 Liver transplantation is still an option to percent chance in each pregnancy for the child prevent liver cancer. It also may be considered to have tyrosinemia 1. There is a 50 percent for children who show signs of liver cancer or chance for the child to be a carrier, just like the liver failure. If you have questions, talk to your parents. And, there is a 25 percent chance for metabolic doctor or doctor about the benefits the child to have two working genes. and risks of transplantation. Can other members of the family have What happens when tyrosinemia 1 is tyrosinemia 1 or be carriers? treated? When treatment is started early, severe liver, kidney and neurologic symptoms can be FAH 3 of 5 May 2008 Having Tyrosinemia 1 How many people have tyrosinemia 1? If they are healthy and growing normally, older About one in every 100,000 babies in the brothers and sisters of a baby with tyrosinemia United States is born with this condition. 1 are unlikely to be affected. However, finding out whether other children in the family have Does tyrosinemia 1 happen more frequently this condition may be important. Early in a certain ethnic group? treatment can prevent serious health problems. This condition occurs in all ethnic groups Ask your metabolic doctor whether your other around the world. It is found more often in children should be tested. people of French-Canadian background, especially in the Saguenay Lac Saint-Jean Tyrosinemia 1 Carriers region of Quebec. About one in 20 French- Brothers and sisters who do not have the Canadians in this region are carriers. One in condition still have a chance to be carriers like every 1,846 babies in this population is born their parents.