Disease Phenylketonuri
Dr. Tran: I have informed Dr.poole about your predicament and am here to ensure that you clearly understand to details about PKU.
Mr. Lee: Thanks Dr.Tran. We have lots of questions concerning our condition.
Dr, Tran: Okay, you can go ahead.
Mrs. Lee: what brings about disease PKU?
Dr, Tran: To begin with, PKU basis from mutations of a gene that aids an enzyme known as phenylalanine hydroxylase. This enzyme is cardinal for the conversion of amino acid phenylalanine into other substances needed by the body. In instances where PAH gene, is faulty, the body is unable to break down phenylalanine (Park, et al 1998).. Amino acids aid manufacturing of proteins, however, phenylalanine causes harm if it builds up in the body. Precisely, nerve cells found in the brain are very sensitive to phenylalanine. Diverse PAH mutations have consequences of incomplete phenylalanine. Some mutations cause non-PKU hyperphenylalaninemia. However, there are silent mutations that have no an effect. Foods with high amounts of proteins should be avoided as they bring about a buildup of phenylalanine. It buildup to high levels results to the symptoms of PKU.
Mrs. Lee: what are the genetics causes of PKU?
Dr, Tran: the second scenario involves genes, a human being has 23 pairs of chromosomes. Each chromosome carries with it the DNA. DNA is actually the blue print meant for the synthesis of diverse proteins within the body. The DNA has a segment responsible for storing the blue print coding(Park, et al 1998).. The coding is for enzyme phenylalanine hydroxylase that is found in the 12th chromosome. In a case a parent carries a faulty gene; they are referred to as carriers. However, since the parent contains an upright or a normal gene, they lack signs as well as symptoms of PKU. Autosomal recessive trend of inheritance take place when the PKU is transferred to the infant as an end result of parents being carriers. Consequently, in a case where both parents are carriers but PKU fails to manifest itself, then chances of their biological child getting PKU during birth is 25%. Some mutations cause hyperphenylalaninemia that isn’t caused by PKU. But there are also silent mutations that don’t change anything. Foods with a lot of protein should be avoided because they cause phenylalanine to build up. It leads to PKU symptoms when it builds up to high levels.
Mrs Lee: how do mutations affect the role of proteins and why?
Dr. Tran: PKU results from mutations a gene. It is this gene that helps an enzyme referred to as phenylalanine hydroxylase (Park, et al 1998).. This is the enzyme that is vital so as to convert amino acid phenylalanine to other products required by the body. Diverse mutations will result to incomplete phenylalanine. This will cause harm to amino acids consequently amino acids are responsible for the manufacturing of proteins. Phenylalanine is present in all proteins. Our bodies use an enzyme known as phenylalanine hydroxylase so as to change phenylalanine to tyrosine, a non important amino acid. The body requires tyrosine to develop neuro transmitters, like epinephrine, dopamine and norepinephrine.
Mr. Lee: How does the mutant molecule affect the other cellular molecules?
DR. Tran: PKU is caused by a fault in the PAH gene. The PAH gene aids the making of phenylalanine hydroxylase, this enzyme breaks down phenylalanine (Park, et al 1998). Consumption of high protein foods can results to a buildup of phenylalanine. This is the building block of proteins. If it builds up to harmful levels then it will cause some of the symptoms of PKU which normally vary from mild to severe.
Mr. Lee: we are really glad that you evaluated and gave us a detailed information about PKU. Thank you.
Park, Y. S., Seoung, C. S., Lee, S. W., Oh, K. H., Lee, D. H., & Yim, J. (1998). Identification of three novel mutations in Korean phenylketonuria patients: R53H, N207D, and Y325X. Human mutation, 11(S1), S121-S122.
