Phenylketonuria Phenylketonuria, otherwise known as PKU, is a rare genetic disease that is caused by a person’s body being unable to metabolize the amino acid phenylalanine. The disease can cause mental retardation because the build up of phenylalanine in the body. When phenylalanine is not broken down and turned in a different amino acid, tyrosine, it can create other enzyme routes that build up in the blood stream and body tissue. This can be extremely harmful to the body and its development. This disease is caused by missing the enzyme phenylalanine hydroxylase, this enzyme is the one that normally breaks down phenylalanine. It is rare for this enzyme to be completely absence, but this form leads to the most severe mental …show more content…
PKU is passed on in a “autosomal recessive” gene. This means that a person may have one of the genes for the disease but if they have the other dominant gene they will not be affected by the disease. In the diagram ‘P’ is the dominant gene and ‘p’ is the recessive gene. People who have one recessive gene and one dominant gene ‘Pp’ are called silent carriers. The person with ‘PP’ does not have any of the PKU gene. The person with ‘pp’ has PKU. Each time two carriers reproduce the chances the baby of having PKU is 25%. The chances of them being a silent carrier is 50%. One in every about fifty people in the general population are carriers. And the chances of that carrier’s mate is a carrier is about one in 2500. PKU occurs in about one of out every 10,00 babies born in the United States. Incidents of this disease occur equally in male and female babies. (Schuett) Screening for PKU is now done in every state for all newborn babies. The test, called the heel stick test, is done at about three days old, to get early detection. Early detection is the key when treating PKU. If at an early age the baby’s diet is changed to avoid phenylalanine, a baby who was once destined to become severely mental retarded, now can live their lives fully without any symptoms of the disease. A baby who has PKU must immediately be kept away from foods containing protein, because protein contains high levels of
In this assignment I am going to describe two physiological disorder in details, the details that I am going to go into is what the disorder is, signs and symptoms, cause of the disorder, physiological changes as a result of treatment and the factors influencing the development of the disorder, explain the signs and symptoms related to two named physiological disorders, describe the investigations that care carried out to enable the diagnosis of these physiological disorders and assess possible difficulties involved in the diagnosis of the disorders from their signs and symptoms.
According to research, PKU is “an autosomal recessive genetic disorder characterized by mental retardation due to a deficiency in phenylalanine hydroxylase, an enzyme necessary to metabolize the essential amino acid phenylalanine to tyrosine. Without phenylalanine hydroxylase, phenylalanine is converted to neurotoxic phenyl pyruvic acid” (Gonzalez, 2009). For those who have PKU, the phenyl pyruvic acid would become quite toxic and lead to damage within the brain causing mental retardation. PKU was first discovered in 1938 by a man named Asbjorn Fölling, and throughout the early 1960s phenyl pyruvic acid was found in urine using a reaction with ferric chloride. However, it was in 1958, that Dr. Guthrie transferred to the Buffalo Children’s Hospital and was able to develop a new approach to measure and monitor
This disease is genetically inherited and is a dominant characteristic, therefore unfortunately the offspring of a victim has 50% chance of inheriting the disease.
The majority of people diagnosed with PKU have survived because it is not a life threatening condition and if its not treated it only leads to mental retardation at its worst.
Diabetes is a lifelong disease that can affect both children and adults. This disease is the sixth leading cause of death in the United States. It claims about 178,000 lives each year. Type one diabetes, also known as insulin dependent diabetes mellitus, usually occurs in people less than thirty years of age, but it also may appear at any age. Diabetes is a very serious disease with many life threatening consequences, but if it is taken care of properly, diabetics can live a normal life.
It is an inherited genetic disease. It is passed down in families in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show any symptoms. Around 1 person in every 150 people are thought to be carriers. There are two types of Krabbe disease the infantile and the late on-set. The infantile form, which affects 85 to 90% of people with
PKU, also known as Phenylketonuria, is a genetic disorder that builds up the amino acid phenylalanine in the human body. This genetic disorder is known to be an example of the norm of reaction. The norm of reaction defines itself as a phenotype range that a person with a certain genotype reveals due to the differing of a certain environmental condition. Since this genetic mutation targeted the gene that encrypts the enzyme phenylalanine hydroxylase, it shows that if a person has one and/or two copies of that certain gene, that person would have the ability to eat and metabolize foods with phenylalanine. But, if a person has two copies of the mutated gene, they wouldn’t be able to eat nor metabolize foods with phenylalanine because if a person with PKU were to ingest foods with phenylalanine, the amino acid will accumulate in their body and become highly toxic to the person and the PKU homozygotes will lead to an assortment of detrimental symptoms, which currently occurs in about 1 in 10,000 babies.
The specific metabolic disorder that I picked for this discussion is Krabbe Disease or globoid cell leukodystrophy. The disease destroys the protective coating of nerve cells in the brain and throughout the body causing the nerve cells to stop responding or react unpredictably. The disease is caused by a person receiving two copies of a mutated gene that results in severely curtailed production of an enzyme called galactocerebrosidase (GALC) (Krabbe disease, n.d.). This enzyme is responsible for breaking down certain substances in a cell's recycling center. Unfortunately, in Krabbe disease, not enough GALC was produced so the cells begin accumulating fats called galactolipids which normally are responsible for maintaining the protective coating
Phenylketonuria, or PKU, is an autosomal recessive, heritable disease that decreases levels of the enzyme phenylalanine hydroxylase, which is responsible for the metabolism of the amino acid phenylalanine, resulting in an unhealthy buildup that can lead to brain damage, seizures, and intellectual disability. While not curable, PKU, if detected early on, can be treated to allow sufferers to lead full and healthy lives. The symptoms of PKU appear almost immediately after birth, requiring parents and hospitals to make the necessary preparations, including feeding infants with special formula. Lack of such care can result in
Hyperkalemic Periodic Paralysis Disease (HYPP) is a muscular disorder found prominently in horses that occurs due to an inherited genetic mutation [1]. Specifically, a point mutation in the sodium channel gene, found in the muscle of affected horses, is passed on to offspring [1]. Sodium channels found in the muscle cell membrane primarily control muscle fiber contraction [1]. According to research summarized by UC Davis, when this defective sodium channel gene is present, the channels “leak” due to fluctuation of blood potassium levels, causing the muscle to depolarize and to contract involuntarily [4]. These fluctuating potassium levels may result from a period of fasting, followed by intake of high potassium feed, such as alfalfa [1]. Ultimately, the depolarization causes the muscles to lose their effectiveness, and myopathy eventually develops [4]. All horses positive for the HYPP gene mutation are affected for their entire lives [2].
In the United States, Phenylketonuria (PKU) affects about 1 in 10,000 to 15,000 newborn babies, making it a very uncommon genetic disorder (U.S National Library of Medicine, 2016). Phenylketonuria stems from an abundant buildup of an essential amino acid called phenylalanine that can become very dangerous when it reaches excessive levels (U.S.National Library of Medicine, 2016). The excessive buildup of phenylalanine is caused by an alteration in the gene which codes for the enzyme known as phenylalanine hydroxylase (PAH), which functions in breaking down the aforementioned essential amino acid phenylalanine (U.S National Library of Medicine, 2016). This genetic mutation is caused by an autosomal, recessive genetic mutation in chromosome 12 (Genetic Science Learning Center, 2016).
PKU stands for phenylketonuria and is an amino acid disorder. PKU is defined as an inborn error of metabolism. Specifically, it characterized by the bodies inability to covert phenylalanine to tyrosine. Moreover, PKU occurs due to a phenylalanine hydroxylase deficiency. An infant develops PKU by inheriting it from their parents. Also, it is referred to as an autosomal recessive trait. Moreover, the infants are missing an phenylalanine hydroxylase enzyme. The method that is used to complete the screening is obtaining a blood sample, and then measuring the amount of Phe and Tyr. Also, genetic testing can be done by obtaining a blood sample. The complications that may arise in infants diagnosed with PKU is that the levels of phenylalanine and
What is PKU? Well PKU stands for "phenylketonuria". It's a type of amino acid disorder. People with this disorder have trouble breaking down an amino acid named phenylalanine from the food they consume. This type of disorder is a group of rare inherited conditions. They are caused by enzymes that do not function correctly. PKU is always tested right after birth in the United States. It is important to find this disease early as it can cause severe brain damage. It is usually done in the first few days after birth and as early as 24 hours after birth. It may be repeated within the first week or two after birth. If tested positive, the damage caused by PKU may begin weeks after the baby has consumed formula or breast milk. Babies with this disease
The benefit of PKU testing outweighs the potential risk. PKU can have devastating effects if not caught early. It is vital that treatment is initiated within the first 72 hours of life. PKU can be effectively managed if caught in time. The implementation of PKU testing has prevented millions of infants from experiencing the effects of intellectual disability and behavior abnormalities. Individuals with PKU can be successfully managed with monitoring of PKU levels and dietary modifications. The testing is cost effective and has high sensitivity and specificity. The estimated cost associated with the treatment of an individual with mental and intellectual disabilities can be millions of dollars. The population screening of metabolic disorders
It was found in recents studies that KS is most commonly inherited maternally. Due to the regular levels of aneuploid sperm men produce, all men in the general public have a risk of producing an aneuploid child, therefore producing a child with KS. Knowing this, a man does not necessarily have to have KS to still produce a child with Klinefelter syndrome however it is more common for a child to inherit Klinefelter syndrome if his father also has KS.