Deficiency diseases in children include those diseases that are a result of having an insufficient amount of a particular enzyme. Enzymes are substances that are needed by your body to speed up a vital chemical reaction. Without the enzyme, the reaction will happen too slowly. Not only will the product that your body is trying to make not be made at all, but the substance that depends on the enzyme will accumulate. This reaction causes disease.
Alkaptonuria
This is a hereditary disease, caused by the deficiency of an enzyme called homogentisic acid oxidase. This enzyme is important in the metabolism of two amino acids (called phenylalanine and tyrosine). Without it, the amino acid tyrosine (made from phenylalanine) is not broken down and a substance called homogentisic acid will accumulate in the child's connective tissue. This accumulation will cause the child's urine to have a dark color. As an adult, it could also cause cartilage to look dark blue, as well as joint disease and heart problems.
Essential Fructosuria
This disease is caused by a deficiency of an enzyme called fructokinase. This results in fructose accumulating and appearing in the child's urine after a meal that contains fructose or sucrose. The fructose in the urine, called fructosuria, would only be detected by a urinalysis. Otherwise, the child would not have any symptoms.
Hereditary Fructose Intolerance
According to Gerhard Meisenberg, PhD, in "Principles of Medical Biochemistry," this deficiency disease is caused by a hereditary deficiency of an enzyme called frustose-1-phosphate aldolase B. The insufficient amount of this enzyme causes frustose-1-phosphate to accumulate. Children will have nausea and vomiting after they eat meals with either fructose or sucrose, and they will be weak, shaky and sweaty. If they are not treated, the accumulation of fructose-1-phosphate can damage their liver, causing it to become enlarged and eventually leading to liver failure.
Galactosemia
Dr. Meisenberg writes in "Principles of Medical Biochemistry," that this deficiency disease is also hereditary and is caused by the deficiency of an enzyme called galactose-1-phosphate-uridyltransferase. Without the necessary amount of this enzyme, substances called galactose and galactose-1-phosphate will accumulate after children eat food which contains galactose and after they drink milk. Children will show symptoms weeks after they are born. They will vomit, be jaundiced and develop an enlarged liver. If they are not treated, not only will they develop cataracts, but it is possible to develop mental retardation and liver failure.
Adenosine Deaminase Deficiency
This is a hereditary disease where children have a deficiency of an enzyme called adenosine deaminase, an enzyme needed to remove waste products from white blood cells called T lymphocytes. These cells are part of your immune system, designed to fight against foreign invaders. But without this particular enzyme, your T lymphocytes are destroyed. Children with this deficiency disease will have recurring infections, diarrhea and abnormalities in their skeleton.
Lesch-Nyhan Syndrome
Lesch-Nyhan is a hereditary disease in which male children are deficient in an enzyme called HGPRTase (hypoxanthine-guanine phosphoribosyltransferase). This enzyme is vital in order to be able to reuse the "recycled" parts of cells for making DNA. Male children with this disease have mental retardation. They might be very aggressive, compulsive and engaged in self-mutilation. In addition, they can have gout and make either spastic or writhing muscular movements.
References
- "Current Diagnosis and Treatment: Pediatrics"; William Hay, Jr., M.D., Myron Levin, M.D., Judith Sondheimer, M.D., Robin Deterding, M.D.; 2009
- "Current Medical Diagnosis and Treatment 2009"; Stephen McPhee, M.D., Maxine Papadakis, M.D.; 2009
- "Principles of Medical Biochemistry"; Gerhard Meisenberg, PhD, William Simmons, PhD; 1998
