Aminoaciduria-Symptoms, Causes, Test & Treatment

What is AminoAcidUria:

Aminoaciduria is a term used for the increased or decreased/abnormal excretion of amino acids in urine. Amino acids are high renal threshold substances. Means majority of them are reabsorbed from the urine and very less are excreted in urine.

There are two types of amino acids on the basis of its excretion amount in urine. These are the following:

• Amino acids that are excreted in small amounts in urine. There approximate value is 0-25mg per twenty four hours of urine. Means if these amino acids are found above then 25mg per 24 hours of urine then it means that the person is suffering from aminoaciduria .Some examples of these aminoacids are tryptophan,tyrosine,serine and leucine etc.
• And amino acids which are excreted in large amount in urine. There average value is 25 to 200 mg per 24 hours of urine. Means if these amino acids are found less then 25 or greater then 200 then it means that the person is suffering from aminoacidurea. Some examples of these amino acids are glycine,taurine,histidinie and glutamine etc.

Aminoaciduria Causes:

When the amount of amino acid is increased or decreased it is termed as amino acid urea but actually it is due to some disease or disorder like diabetes mellitus,acute infections,liver diseases and some genetic disorders etc.

But this increased or decreased level of amino acid in urine can also be due to some physiological conditions like pregnancy etc.

So before treating this disorder, one will need to find the cause of the disorder because as explained earlier, there could be many causes of it.

Classification of aminoaciduria:-

It is classified into three classes:

1. Renal aminoaciduria
2. Overflow aminoaciduria
3. Abnormal excretion of products derived from amino acids.

1. Renal Aminoaciduria:

As the name suggests, this aminoaciduria is due to defect in kidneys. Means that due to any disease or defect, kidneys are not able to reabsorb all the the amino acid and thus they appear in urine.

One example of such amino acid urea is cystinurea. It is a genetic/ inherited disease in which the the absorption of amino acid cystine from the kidneys doesn’t take place. And hence it appears in urine and renal stones are also formed.

2. Overflow Aminoaciduria:

Amino acid can also occur when there is increased amino acids in blood. Means excess of amino acids are passed through kidneys. In this situation when all the amino acids channels i.e sodium, amino acid co transport channels are occupied in there is more and more amino acids, then these extra amino acids would be excreted in urine. Means when renal threshold for absorption is crossed amino acids would come in urine. This type of amino acid urea is called overflow aminoacid urea.

This can be due to many reasons such as surgery, burns, and other physiological conditions in which excess of amino acids are present in blood.