Aspartylglucosaminuria (AGU) is an inherited disease that is characterized by a decline in mental functioning, accompanied by an increase in skin, bone and joint issues.

This enzyme plays a significant role in our bodies because it aids in breaking down certain sugars (for example, oligosaccharides) that are attached to specific proteins (for example, glycoproteins).

These proteins are most abundant in the tissues of the body and in the surfaces of major organs, such as the liver, spleen, thyroid and nerves.

The following signs and symptoms may appear:[3] (Children are physically uncoordinated, but remain able to play sports and do everyday activities until they reach adulthood.)

When a person receives one changed form of the gene AGU from one of the parents, the individual is then classified as a carrier.

[5][6] In order to be diagnosed with AGU an individual takes a urine test, which will show indication of an increased amount of aspartylglucosamin being secreted.

Around the age of 2–4 years, they begin showing signs of developmental delay, but development is still progressing.

This progressive decline continues until about age 25–28, when rapid impairment of abilities occurs, resulting in severe intellectual disability.