The phenylketonuria or PKU is a metabolism disorder which causes the body to not metabolize the amino acid called phenylalanine in the liver It is a hereditary disease caused by the lack of an enzyme known as phenyl alanine hydroxylase (abbreviated as FAOH) or of tyrosine hydroxylase (DHPR) .
He origin This term comes from English phenylketonuria , hence the initials with which this disorder is known (PKU). It is a disease of genetic transmission which is characterized by affecting certain chemical components of the organism whose consequence may be intellectual disabilities.
People born without the phenyl alanine hydroxylase enzyme (enzymes allow certain chemical reactions to be activated in the body) that resides in the liver, can't synthesize phenylalanine coming from food and it begins to accumulate excessively in the body. It should be noted that people who do not suffer from this disease can synthesize this substance and turn it into L-DOPA , a fundamental neurotransmitter for the normal functioning of neurological development. There are seven essential amino acids for people (leucine, tryptophan, valine, isoleucine, tyrosine, methionine and phenylalanine) which are obtained from the synthesis of certain components present in different foods.
Although it is a disease of which there is not so much awareness, it is known that in the United States only, they are born around 25,000 babies a year with PKU; In addition, although the precise origin of it is unknown, it is known to be more common in individuals whose ancestors have been Northern Europeans or native indigenous from North America.
This genetic alteration which is transmitted from father to son had in Ivar Asbjørn Følling to one of its main disseminators. This Norwegian medical expert was the one who described the disease in 1934 , before any other specialist.
Følling He warned that the enzymes mentioned above are responsible for hydroxylating phenylalanine, in a reaction that allows the production of tyrosine. This means that, if the body does not have any of these enzymes, it will suffer an excess of phenylalanine in the blood (since this substance will not become tyrosine), and will result in others disorders .
The accumulation of phenylalanine and other substances (such as phenylpyruvate ) generate damage to the brain and central nervous system. Those who suffer from phenylketonuria can experience from a mental disability to seizures and spasms, through tremors and skin rashes.
The symptom presented by those children who suffer from this disease are hair color, eyes and skin of a lighter color than the rest of his brothers (phenylalanine is one of the main responsible in the production of melanin, which allows the coloring on the skin and hair),delay in intellectual abilities , a head of smaller size than expected, sudden movements and hyperactivity attacks of seizures and tremors , unusual posture of the hands. It should be added that those who do not receive treatment or avoid foods that contain phenylalanine, begin to eliminate a weird smell (comparable to the one fired by mice or mold) through the skin, urine and breath; This smell is due to the accumulation of this substance in the body.
Diagnosis and treatment
Thanks to the tests and diagnoses that allow to detect this disease in newborn children, it is possible to treat this condition by helping those individuals to grow and develop in a healthy way. The treatment of phenylketonuria usually includes a diet which excludes foods with high amounts of phenylalanine, such as eggs or milk.
To detect phenylketonuria, simple ones are performed blood test (In some countries this test is among the obligatory ones that are carried out to the neonates), in case of positive, new analyzes are carried out in order to confirm the diagnosis and proceed to the treatment.
It is important that we know that this disease is perfectly treatable and that a series of preventions will be enough to ensure healthy growth for those children who suffer from phenylketonuria. The treatment includes a diet low in phenylalanine that requires exhaustive supervision of professionals, which if carried out correctly will ensure an adult life in the physical and mental aspects much healthier than if it is done in a little compromised way.
Foods such as milk, eggs and all those containing aspartame (like the artificial sweetener Nutrasweet) they have phenylalanine and are the first ones that should be avoided when making such a diet.
exist alternatives specially developed for people who suffer from this disease that allow them to lead a healthy life without having to dispense with fundamental foods for growth, such as milk. Lofenalac infant milk powder, for example, is used as a source of protein for individuals with phenylketonuria, which is made with a low phenylalanine content and balanced in terms of the amount of the rest of the essential components for growth, such as amino acids.
In addition, it is of vital importance that those parents who have children with this disease have a clear awareness of the consequences that could affect them if said disease is not treated, or if the diet recommended by specialists is not properly performed, among which is a chronic mental retardation that will be presented in the first year of life and that will be irrevocable. Likewise, if parents do not know if they can carry the gene of this disease in their genes, it is essential that when thinking about conceiving a new life the respective enzymatic analyzes are carried out, in order to be prepared, in case their children can be carriers of such ailment.
Finally, those women who suffer from phenylketonuria should perform a strict diet , not only before becoming pregnant, but during pregnancy and the time of breastfeeding, even if the baby was born without the defective gene, because the accumulation of this substance in the mother's body could cause consequences in the child's organism.