Kiranjit Singh April 4, 2014
PHENYLKETONURIA
Phenylketonuria, also known as PKU is an autosomal recessive disorder. PKU
is a rare disorder. Only one out of fifteen thousand people in the US are born
with it. PKU is an inherited disease which means that it is passed down through
generations. This disorder increases the levels of phenylalanine in the blood.
Phenylalanine is an amino acid, also known as a building block of proteins that
is taken in through the diet that the person eats.
Proteins are essential to our body. We need them to repair tissues and
make new cells. Amino acids are 20 different building blocks that are made of
protein. Protein comes from fish, meat, eggs, nuts and beans that everyone
eats. Our bodies are designed to breakdown those proteins into amino acids. Any
of the amino acids that are not essential to the body are disposed and are
released through the urine. One of the amino acids is called phenylalanine. Phenylalanine
cannot process through the bodies of people who are diagnosed with PKU. If phenylalanine
cannot be processed, it will cause a buildup in the blood. This buildup will
affect your nerve cells and that causes brain damage.
The only way PKU can occur is when the child is born with the disease.
The person most likely affected is the child. Plus there is no other way an
individual can inherit this disease unless they are born with it. In order for
the child to be affected, both parents have to have the recessive-diseased
allele. Even if both parents do not have PKU, they can still be carriers of the
disease if they are heterozygous. If both parents are heterozygous then there
is a 25% chance that their baby might have the disease. Nonetheless, if the
child is affected, then that means that the child is homozygous recessive. Furthermore,
even if one parent is the carrier of the disease (heterozygous) and the other
parent has the disease (homozygous recessive) then that means that there is a
50% chance that the baby will be normal and a 50% chance that the baby will
have the disease.
Babies are born with PKU. As soon as the baby is born, it is the doctor’s
job to test the baby for PKU with a simple blood test. The reason only newborn
babies are affected by this disease is depending on if the parents have the
diseased allele. If the parents do not have the diseased allele then there is
no possibility that the child will be diagnosed with that disease.
If PKU is not treated early, as in if the parents are unaware that their
baby had this disease, what will happen is that the first few months the baby
will seem to be normal but after that time period you will notice the symptoms.
You will notice that the baby has started to lose interest in things when they
are 3 to 7 months old. When the baby is one year old, it starts to become
obvious that the baby’s brain is not developing the way a normal baby’s brain
would develop. Other symptoms include dry skin, seizures, rash or the baby
starting to get smelly because the phenylalanine is in their urine, breath and
sweat. Often, kids with untreated PKU have small heads called microcephaly. This
means that if this disease is not treated on time then the phenylalanine can
build up into harmful levels in the body. This can cause permanent mental
retardation along with other health problems.
Thankfully, PKU is a treatable disease. The treatment involves the
person to have a diet with low in phenylalanine, preferably when the child is
growing. It is important that this diet be strictly followed. A person with PKU
can live a normal healthy life span with a normal mentality if they continue on
with this diet for the rest of their lives. The only problem there can be in
the treatment of this disease is if this disease is not caught on time. If this
is the case then the individual can suffer through permanent intellectual
disability.
Do you think people who are diagnosed with PKU should have children and
risk causing their disease to pass onto their children? Why or why not?
References:
I never knew that their was a disease called Phenylketonuria. After reading this blog about the disease I was really interested and amazed to know that only one out of fifteen thousand people in the US are born with this disease. I also learnt about how this disease is carried and who the carrier is. Overall I loved the way you put out your information as every question that came in my mind was answered from reading the blog. I think a video would have been good to add in your blog. Overall the blog was good:) TEGVIR
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