What is phenylketonuria PPT?
Phenylketonuria (PKU) is an inborn error of metabolism that results in decreased metabolism of the amino acid phenylalanine. A birth defect that causes an amino acid called phenylalanine to build up in the body. Newborns should be screened for PKU.
What is the PAH gene?
The PAH gene provides instructions for making an enzyme called phenylalanine hydroxylase. This enzyme is responsible for the first step in processing phenylalanine, which is a building block of proteins (an amino acid) obtained through the diet. Phenylalanine is found in all proteins and in some artificial sweeteners.
How PKU is diagnosed?
PKU is diagnosed with a blood test. In the United States and most other countries, a blood test is taken through a heel stick on newborn babies within 48 hours of birth. Further tests will be required to confirm the type of PKU and plan the best way of treating it.
What is phenylketonuria PDF?
Phenylketonuria (PKU) is an autosomal recessive inborn error of phenylalanine (Phe) metabolism resulting from deficiency of phenylalanine hydroxylase (PAH). Most forms of PKU and hyperphenylalaninaemia (HPA) are caused by mutations in the PAH gene on chromosome 12q23.
What are types of phenylketonuria?
There are two main types, classic PKU and variant PKU, depending on whether any enzyme function remains. Those with one copy of a mutated gene typically do not have symptoms. Many countries have newborn screening programs for the disease.
How big is the PAH gene?
90 kb.
The human PAH gene, which is located on chromosome 12q, consists of 13 exons spanning 90 kb. To date, more than 520 different mutations in the PAH gene have been characterized in PKU patients and recorded in the PAH Mutation Analysis Consortium Database (http://www.pahdb.mcgill.ca).
How long is the PAH gene?
90 kb
The PAH gene is 90 kb in length (about 171 kb if flanking regions are included) with 13 exons. Locus-specific databases, such as PAHdb (http://www.pahdb.mcgill.ca) and BIOPKU (http://www.biopku.org), have been an important resource for understanding the nature, prevalence, and impact on PAH deficiency.
What do you do if PKU is positive?
If the first phenylalanine test demonstrates positive results, a repeat test should be performed. Treatment to prevent sequelae from this disorder is best carried out in cooperation with an experienced PKU center. Dietary care is expensive, and financial assistance may be necessary for many families.
When should 2nd PKU be done?
The American Academy of Pediatrics recommends that a PKU screening test be repeated by two weeks of age if it was performed before the newborn was 24 hours of age.
