Phenylketonuria (commonly known as PKU) is an inherited disorder that increases the levels of a substance called phenylalanine in the blood. Genetic disorder diseases Phenylalanine is a building block of proteins ( an amino acid ) that is obtained through the diet. A genetic disorder It is found in all proteins and in some artificial sweeteners. Example of genetic disorder If PKU is not treated, phenylalanine can build up to harmful levels in the body, causing intellectual disability and other serious health problems.
The signs and symptoms of PKU vary from mild to severe. What is a recessive genetic disorder The most severe form of this disorder is known as classic PKU. Recessive genetic disorder definition Infants with classic PKU appear normal until they are a few months old. 5 genetic disorders Without treatment, these children develop permanent intellectual disability.
Y linked genetic disorders Seizures, delayed development, behavioral problems, and psychiatric disorders are also common. Genetic disorder symptoms Untreated individuals may have a musty or mouse-like odor as a side effect of excess phenylalanine in the body. Genetic disorder testing Children with classic PKU tend to have lighter skin and hair than unaffected family members and are also likely to have skin disorders such as eczema.
Less severe forms of this condition, sometimes called variant PKU and non-PKU hyperphenylalaninemia, have a smaller risk of brain damage. At genetic disorder People with very mild cases may not require treatment with a low-phenylalanine diet.
Babies born to mothers with PKU and uncontrolled phenylalanine levels (women who no longer follow a low-phenylalanine diet) have a significant risk of intellectual disability because they are exposed to very high levels of phenylalanine before birth. What causes a genetic disorder These infants may also have a low birth weight and grow more slowly than other children. Xxy genetic disorder Other characteristic medical problems include heart defects or other heart problems, an abnormally small head size ( microcephaly ), and behavioral problems. Genetic disorder research project Women with PKU and uncontrolled phenylalanine levels also have an increased risk of pregnancy loss.
The PAH gene provides instructions for making an enzyme called phenylalanine hydroxylase . What does genetic disorder mean This enzyme converts the amino acid phenylalanine to other important compounds in the body. Which of these is not a genetic disorder If gene mutations reduce the activity of phenylalanine hydroxylase, phenylalanine from the diet is not processed effectively. Which of the following is a genetic disorder As a result, this amino acid can build up to toxic levels in the blood and other tissues. 3 genetic disorders Because nerve cells in the brain are particularly sensitive to phenylalanine levels, excessive amounts of this substance can cause brain damage.
Classic PKU, the most severe form of the disorder, occurs when phenylalanine hydroxylase activity is severely reduced or absent. A dominant genetic disorder occurs when People with untreated classic PKU have levels of phenylalanine high enough to cause severe brain damage and other serious medical problems. Causes of genetic disorder Mutations in the PAH gene that allow the enzyme to retain some activity result in milder versions of this condition, such as variant PKU or non-PKU hyperphenylalaninemia.
This condition is inherited in an autosomal recessive pattern , which means both copies of the gene in each cell have mutations. Genetic disorder library The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition.