PKU Flashcards
what is PKU
A birth defect that causes an amino acid called phenylalanine to build up in the body. The gene concerned (phenylalanine) controls the production of an enzyme called phenylalanine hydroxylase. This enzyme converts the amino acid phenylalanine to tyrosine. If this enzyme is not present, then phenylalanine will accumulate in the bloodstream and become toxic.
The toxicity results in damage to the growing brain, and thus produces extreme mental retardation, as well as a tendency towards epileptic seizures and a failure to produce normal skin pigmentation.
What are the symptoms of PKU with respect to the digestive system
PKU is a rare metabolic disorder. Children with PKU can’t process an amino acid called phenylalanine. Phenylalanine is in many common foods.
It helps the body make protein. It’s also important for brain growth. It’s normally changed to tyrosine, which helps create all of the body’s proteins.
Therefore, people that suffer from PKU must limit foods containing phenylalanine. Which is mostly protein
How do the conditions affect the functioning of the digestive system
Without the enzyme necessary to break down phenylalanine, a dangerous build-up can develop when a person with PKU eats food that contain protein or eats aspartame, an artificial sweetener. This can eventually lead to serious health problems.
What diet modifications are required for PKU
The main way to treat PKU is to eat a special diet that limits foods containing phenylalanine. Infants with PKU may be fed breast milk. They usually also need to consume a special formula known as Lofenalac. When your baby is old enough to eat solid foods, you need to avoid letting them eat foods high in protein. These foods include:
• Eggs
• Cheese
• Nuts
• Milk
• Chicken
• Beans
• Beef
• Pork
• fish
To make sure that they still receive an adequate amount of protein, children with PKU need to consume PKU formula. It contains all the amino acids that the body needs, except for phenylalanine. There are also certain low-protein, PKU-friendly foods that can be found at specialty health stores
How does PKU affect regulation and protection of the body
PKU Is an inherited disorder that increases the levels of a substance called phenylalanine in the blood
The gene concerned (phenylalanine) controls the production of an enzyme called phenylalanine hydroxylase. This enzyme converts the amino acid phenylalanine to tyrosine. If this enzyme is not present, then phenylalanine will accumulate in the bloodstream and become toxic. The toxicity results in damage to the growing brain, and thus porduces extreme mental retardation, as well as a tendency towards epileptic seizures and a failure to produce normal skin pigmentation.
an increased susceptibility to infections has been observed in some patients with PKU. which is not well known whether it is due to alterations of plasma essential amino acid concentrations or to some other factors.
Inheritance patterns of PKU
For a child to inherit PKU, both the mother and father must have and pass on the changed gene. This pattern of inheritance is called autosomal recessive. It’s possible for a parent to be a carrier — to have the changed gene that causes PKU, but not have the disease. As PKU is inhertited in a autosomal recessive fashion, all children of a mother with PKU will inherit 1 affected gene.
The genetic cause of PKU
PKU is caused by a change in the phenylalanine hydroxylase (PAH) gene. This gene helps create the enzyme needed to break down phenylalanine.
PKU affects chromosome 12
Occurrence of the allele in in the Australian population
it affects approximately 1 in 10,000 people in Australia
Rate of occurrence of PKU in newborns in Australia
Around one in 10,000 babies born in Australia has PKU.
Survival rates past and present for PKU
Without treatment, PKU can cause intellectual disabilities. PKU does not shorten life expectancy, with or without treatment
Find the treatments applied for PKU
The main treatment for PKU is a low protein diet that completely avoids high protein foods (such as meat, eggs, and dairy products) and controls the intake of many other foods, such as potatoes and cereals.
the drug kuvan for the treatment of PKU. Kuvan is a cofactor for phenylalanine hydroxylase which helps improve the PKU patient’s innate PAH enzyme activity and increase their Phe tolerance.
Palynziq can be used in adults with PKU. Palynziq is an enzyme, injected under the skin every day by the patients, that circulates in the blood, metabolising Phe, and substitutes for the defective phenylalanine hydroxylase enzyme. Palynaiq works well for many adult PKU patients but can have serious side effects in some patients.
Taking a PKU formula- a special nutritional supplement for life to make sure that you get enough essential protein
Community support groups that help families with members with PKU
The children’s PKU network (CPN) is a non-profit organization dedicated to providing support and services to children with PKU, their families and all those involved in the treatment of this disorder.
• National PKU Alliance
• Children’s PKU Network
• National PKU News
• New England Consortium of Metabolic Programs
• University of Washington, PKU clinic
• Mid-Atlantic Connection for PKU and Applied Disorders
• PKU Toolkit
• PKU Association of NSW
• PKU.com
• Intermountain PKU and Allied Disorders Association
• National Society for Phenylketonuria
What test can be done to identify sufferers and carriers of PKU
The disease can be identified almost immediately after birth. A blood sample is usally taken by pricking the baby’s heel (called a heel prick)
If a child or adult shows symptoms of PKU, such as development delays, the doctor will order a blood test to confirm the diagnosis. This test involves taking a sample of blood and analysing it for presence of the enzyme needed to break down phenylalanine
general symptoms
• A musty odor in the breath, skin or urine, caused by too much phenylalanine in the body
• Nervous system (neurological) problems that may include seizures
• Skin rashes, such as eczema
• Lighter skin, hair and eye color than family members, because phenylalanine can’t transform into melanin — the pigment responsible for hair and skin tone
• Unusually small head size (microcephaly)
• Hyperactivity
• Intellectual disability
• Delayed development
• Behavioral, emotional and social problems
• Mental health disorder
Phenylalanine
is an essential ammino acid
