Introduction:
Inborn errors of metabolism are genetic and rare disorders where the body does not turn food into energy. Such disorders are generally caused by defects in certain types of proteins (enzymes) that help the body to break down or metabolize food particles. A food product that cannot be broken down and cannot be transformed into energy builds up in the body and may cause various symptoms. Inborn errors of metabolism can cause developmental delays or any other medical problem if they are not controlled in time. Metabolism is defined as the chemical reaction in the body that is responsible for changing food into energy. The human body depends on this energy to carry out day-to-day activities. Specific proteins in the body control chemical reactions to produce energy. These metabolic reactions happen at the same time and are regulated by the body in such a way that the body’s cells stay healthy and in working condition. Inborn errors of metabolism are a huge group of rare inherited diseases that usually result from a defect in an enzyme or any transport protein, eventually leading to a blocked metabolic pathway. Effects occur due to the toxic accumulation of substrates preliminary to the block, mediated by an alternative metabolic pathway, flawed energy production, and a deficiency of products.
What Are Inborn Errors of Metabolism?
Inborn errors of metabolism are defined as genetic and uncommon conditions. In these conditions, the body does not transform food into energy. Various types of proteins or enzymes help the body break down or metabolize food. In these conditions, defective proteins can be seen, and the body becomes unable to metabolize the food. Inborn errors of metabolism are an assorted group of disorders that can be inherited or may result from spontaneous mutations. These diseases or disorders are behind the collapse of the metabolic pathway, participating in the breakdown or storage of carbohydrates, fatty acids, and proteins. These inborn metabolism errors are rare and occur in 1 in 2000 to 2500 births. It is stated that these conditions can present at any age, and hence awareness of these diseases is important. Sometimes, these diseases' evaluation, diagnosis, and management become critical for the medical team. If the inborn errors of metabolism are not controlled in time, then developmental delays or medical problems may occur. Inborn errors of metabolism are often present at birth as they are inherited. Newborn babies are usually screened for various serious conditions, which include metabolic, hormonal, and blood-related disorders. If these conditions are detected early and prompt management and treatment are provided, then lifelong health problems can be prevented. There are many types of inborn errors in metabolism and some are mentioned below:
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Fructose intolerance.
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Maple sugar urine disease (MSUD).
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Phenylketonuria (PKU).
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Urea cycle disorder (UCD).
What Is the Process of Metabolism?
Metabolism is a process in which chemical reactions occur in the cells of the body that eventually change food into energy. This energy is used by the human body to carry out various tasks and activities. Some proteins in the body are responsible for the chemical reactions occurring in metabolism. The various metabolic reactions occur at the same time and are regulated by the body. This process of metabolism keeps the body healthy and in working order. When we eat food, the digestive system uses enzymes to break down proteins into amino acids, fats into fatty acids, and carbohydrates into simple sugars. The body uses sugar, amino acids, and fatty acids as energy sources when needed. These compounds get absorbed into the blood, which carries them to the cells. After they enter the cells, other enzymes initiate the chemical reactions involved in the process of metabolizing the compounds. During this process, energy is released from the compounds for use by the body or is stored in body tissues, especially in the liver, muscles, and fat. A metabolism is a balancing act involving two activities simultaneously, known as anabolic or constructive activity and catabolic or destructive activity. Several hormones are involved in the process of metabolism and also direct the process. In short, metabolism is a short process.
What Is the Etiology of Inborn Errors of Metabolism?
Inborn errors of metabolism characterize a group of more than 900 disorders that are genetically inherited and can also be caused by mutations in gene coding. The inborn errors of metabolism are inherited as autosomal recessive, autosomal dominant, and X-linked disorders, but most of them are autosomal recessive. It was thought that single-gene mutations caused inborn errors of metabolism, but then it was realized that they might arise due to different genetic defects. Thus, various factors such as environment, epigenetics, microbiome, etc., are potential modifying etiologic factors in individual inborn errors of metabolism.
What Are the Signs and Symptoms of Inborn Errors of Metabolism?
There are various conditions of inborn errors of metabolism and signs and symptoms depend upon the specific condition. A few of the signs and symptoms are given below:
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Hampered growth in babies and children.
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Unintended weight loss and inability to weight gain in babies and children.
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Lack of energy and fatigue.
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Hypoglycemia (occurs when the level of glucose in the blood drops below what is known as healthy).
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Poor feeding habits.
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Problems related to digestion.
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Vomiting and nausea.
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High levels of acid or ammonia in the blood.
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Abnormal liver function.
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Developmental delays in babies or children.
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Seizures or any neurological problems.
What Are the Ways to Treat and Manage Inborn Errors of Metabolism?
The treatment plan relies on certain disorder of the metabolic disorder and a few of the typical treatments include the following:
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Change in Diet and Lifestyle: The patient should avoid certain kinds of food that the body would not be able to handle and break down.
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Medicines: Medicines can be used to manage certain symptoms and help the patient feel better and avoid emergencies.
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Enzyme Replacement Therapy: Injections of a deficient enzyme may help in some way to manage and treat the specific disorder.
Conclusion:
The prognosis varies according to the individual inborn error of metabolism and can differ for different forms of a particular inborn error of metabolism. An early diagnosis and rapid treatment of inborn metabolism errors can save the patient's life. The rate of mortality may be higher for certain types of inborn errors of metabolism, especially those present in neonates, and also for some presentations of inborn errors of metabolism in adults. These groups of diseases may also affect a particular organ or an organ system, leading to morbidity due to acute or chronic organ dysfunction. Most of the patients suffering from inborn errors of metabolism may need monitoring in intensive care units. Progression can be rapid, with life-threatening deterioration within hours, episodic along with intermittent decompensations and asymptomatic intervals, or slow degeneration over a longer period, which can be in decades. This condition cannot be prevented as it is hereditary, but it can be managed with early diagnosis and prompt treatment.
