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Phenylketonuria
Can patients with phenylketonuria eat fish and shrimp?
Children with phenylketonuria cannot eat fish and shrimp because phenylketonuria is caused by a deficiency of phenylalanine hydroxylase in the phenylalanine metabolic pathway, leading to metabolic disorder of phenylalanine in the liver. Phenylketonuria is the first hereditary metabolic disease that can be controlled by diet, as natural foods contain certain amounts of phenylalanine. Therefore, once diagnosed, children with phenylketonuria should stop consuming a natural diet and should be treated with a low phenylalanine diet. Fish and shrimp contain rich protein and high levels of phenylalanine, hence children with phenylketonuria cannot eat fish and shrimp.
What tests do parents with phenylketonuria undergo?
Parents with phenylketonuria can undergo chromosome testing. Phenylketonuria is a common amino acid metabolic disease and an autosomal recessive genetic disorder. Currently, it is mainly screened after the birth of the child by testing the blood for phenylketonuria. Phenylketonuria can also be screened prenatally before the birth of the newborn. Screening can be conducted by extracting amniotic fluid from the pregnant woman for genetic screening through amniocentesis between the 16th and 20th weeks of pregnancy. If chromosomal abnormalities are detected through amniocentesis, it indicates that the fetus carries the pathogenic gene, proving that the child will have phenylketonuria after birth. Couples carrying related genes also need to undergo prenatal screening.
When do people with phenylketonuria need to eat a special diet until?
Phenylketonuria is the first genetic metabolic disease that can be treated through dietary control. Since natural foods contain certain amounts of phenylalanine, once children with phenylketonuria are diagnosed, they should stop consuming a natural diet and start a low-phenylalanine diet treatment. Treatment with a low-phenylalanine formula should continue at least until the age of 12. When the concentration of phenylalanine in the blood is controlled at an ideal level, gradually small amounts of natural diet can be reintroduced. The food added should adhere to the principles of being low in protein and phenylalanine.
Can people with phenylketonuria not eat things high in protein?
Phenylketonuria patients should avoid foods high in protein, as phenylketonuria is a common amino acid metabolism disorder caused by a deficiency of phenylalanine hydroxylase in the metabolic pathway of phenylalanine, leading to disordered metabolism of phenylalanine in the liver. Phenylketonuria is a hereditary metabolic disease that can be managed through diet. Natural foods contain certain amounts of phenylalanine. Once diagnosed, the patient should cease consuming natural diets and switch to a phenylalanine-restricted diet. Foods rich in protein have higher amounts of phenylalanine, thus, those with phenylketonuria should not consume foods high in protein.
Phenylketonuria positive means what?
Phenylketonuria is an autosomal recessive inherited disease and is the most common congenital amino acid metabolism disorder. Generally, if the activity of phenylalanine hydroxylase in the body is reduced, or if there is a deficiency in its coenzyme tetrahydrobiopterin, the concentration of phenylalanine in the blood and tissues will increase, and phenylpyruvic acid, phenylacetic acid, and phenyllactic acid in the urine will also increase. Generally, newborns may not show any special clinical features at first. Often, the first test results may be high due to maternal influence or dietary factors, which can cause these elevated indicators in newborns. If the second test is normal, there usually isn’t a significant problem. A third test can also be performed; if the third test still shows no issues, then phenylketonuria can be ruled out. Generally, if phenylketonuria is diagnosed, it should be treated promptly and properly.
Phenylketonuria has what symptoms?
Phenylketonuria is an autosomal recessive genetic disorder. It is the most common congenital amino acid metabolism disorder. Its main clinical characteristics include intellectual disability, light skin and hair pigmentation, and a mousy urine odor. This name arises from the excretion of large amounts of phenylketonic acid metabolites in children's urine, which leads to the characteristic odor. Typically, affected children appear normal at birth, but symptoms usually begin to appear between three to six months of age, with most significant symptoms evident by one year. The most prominent issue is delayed intellectual development, with intelligence quotients often falling below normal. Skin pigmentation usually becomes lighter several months after birth due to insufficient melanin synthesis, resulting in hair turning from black to yellow and a paler skin complexion. Additionally, a distinct mousy body odor is produced due to the excretion of excessive phenylacetic acid in urine and sweat.
Does phenylketonuria require lifelong dietary control?
Theoretically, phenylketonuria requires lifelong dietary control. Phenylketonuria is caused by a deficiency in phenylalanine hydroxylase in the metabolic pathway of phenylalanine, leading to disordered metabolism of phenylalanine in the liver. Phenylketonuria is the first genetic metabolic disease that can be managed through diet. Since natural foods all contain certain amounts of phenylalanine, once diagnosed, affected children should cease consuming natural diets and should be treated with a low-phenylalanine diet. Treatment with a low-phenylalanine formula should continue at least until the age of 12. When the concentration of phenylalanine in the blood is controlled at an ideal level, natural foods can gradually be reintroduced in small amounts. The reintroduction of food should still follow the principles of low protein and low phenylalanine. The types and amounts of food that each child can add vary individually and are related to the severity of the enzyme deficiency.
Can phenylketonuria be cured?
Phenylketonuria is one of the few treatable genetic metabolic diseases. It strives for early diagnosis and treatment to avoid irreversible damage to the nervous system. Once diagnosed, aggressive treatment should be given. The younger the age at which treatment starts, the better the effect. The main approach is to use a low-phenylalanine formula milk. When the blood concentration drops to a normal level, natural diet can gradually be added in small amounts, with breast milk being the preferred choice, as it contains only one-third the phenylalanine of cow's milk. Larger infants can add cow's milk, porridge, noodles, eggs, etc. The added foods should also follow the principle of being low in protein and low in phenylalanine, because concentrations of phenylalanine that are too high or too low will affect growth and development. Low-phenylalanine treatment should continue at least until after puberty. Lifelong treatment is more beneficial for patients. This disease can only control symptoms, and lifelong treatment is the best; it cannot be completely cured.
"Phenylketonuria weakly positive" means what?
The indication of weakly positive phenylketonuria suggests a re-examination of blood phenylalanine levels. Generally, there are no obvious specialized clinical symptoms of phenylketonuria in the newborn period. Some newborns may experience feeding difficulties, vomiting, or irritability, and the manifestations of phenylketonuria gradually appear after three months of age. Currently, hospitals routinely screen newborns for phenylketonuria. This screening is conducted 72 hours after birth and must be completed by no later than 20 days post-birth. If the result of the blood phenylalanine test is weakly positive or positive, further testing is generally recommended to determine whether the infant has phenylketonuria or if other factors are affecting the phenylalanine levels.
Can phenylketonuria be detected before a newborn is born?
Phenylketonuria can be screened prenatally before the birth of a newborn. The procedure involves genetic screening using amniotic fluid drawn through amniocentesis between the 16th and 20th week of pregnancy. Phenylketonuria is an autosomal recessive hereditary disease, greatly associated with chromosomal abnormalities. If chromosomal abnormalities are detected through amniocentesis, indicating the presence of pathogenic genes, it confirms that the fetus will be born with phenylketonuria. If both parents carry the relevant genes, prenatal screening is still necessary to rule out the risk of the disease in the fetus.