Overview Edit

Genes are the portions of DNA used to code for a known function of a protein or process to create a living organism (3). Even though it is the genes that encode for the function, the environment in which the organism lives in also has an effect on the expression, or phenotype, of certain genes (3).  The environment includes living space, exercise routine, diet, temperature, etc.  PKU is an example of a genetic mutation that is effected by the environment.

Phenylketonuria (PKU) Edit

640px-L-phenylalanine-skeletal image

Image 1. Showing the molecular structure of the amino acid Phenylalanine

Phenylketonuria, or commonly known as PKU, is an autosomal recessive genetic disorder where a mutation occurs and disrupts the breakdown of the amino acid Phenylalanine (3).  This occurs due to a mutation in the gene PAH, whose function is to create the enzyme phenylalanine hydroxylase (2). Phenylalanine hydroxylase breaks down this amino acid into different compounds that are important for the body (2). Since the gene’s code is altered and cannot break down into those compounds this causes a buildup of the amino acid phenylalanine which induces a high level of toxicity within the body that can cause damage (2).  Symptoms can range from mild to severe; some symptoms include seizures, delayed development, behavioral problems, intellectual disability, small head size, musty odor and other psychiatric disorders (1). The brain is highly affected by the increased toxic levels of phenylalanine, which causes severe brain damage (2).

Environment's Role Edit

The environment plays a factor with PKU through diet, which is one of the main treatments. The PKU diet consists of limiting foods that contain phenylalanine, which is mostly found in foods containing protein (1). Another method of treatment is a drug called sapropterin (Kuvan) (1). This drug is used with the combination of the PKU diet (1).  My limiting the consumption levels of PKU, the symptoms can be reduced significantly and can allow the person to reduce chance of irreversible brain damage (2).

Resources: Edit

1 Mayo Clinic Staff. Phenylketonuria (PKU). Mayo Clinic. November 26, 2014.

2 Phenylkertonuria. Genetics Home Reference. Published December 1, 2014.

3 Genetics. Wikipedia. 2008.