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. The disease is caused by a defect in an enzyme known as aspartylglucosaminidase. 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). Aspartylglucosaminuria itself is characterized as a lysosomal disease because it does deal with inadequate activity in an enzymes function. Aspartylglucosaminidase functions to break down 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. When glycoproteins are not broken down, aspartylglucosaminidase backs up in the lysosomes along with other substances. This backup causes progressive damage to the tissues and organs. Signs and symptoms
At birth, there is no sign that a child will develop symptoms of aspartylglucosaminuria. Typically, signs and symptoms become apparent between two and four years of age and become progressively worse as the individual ages.
For the developmental symptoms, Educational intervention and speech therapy beginning in infancy could help to reduce the high risk for motor, cognitive, speech, and language delay. For the skeletal features, referral to an orthopedist for consideration of surgical release of contractures. In addition, early referral to physical therapy could help increase joint mobility. Lastly, thyroid hormone replacement could help out the thyroid dysfunction. History
In 1988, Goldblatt et al. first reported a 4-year-old boy with hypoplastic patellae, mental retardation, scrotal hypoplasia, skeletal deformities, kidney anomalies, flattened nasal bridge, and short stature. Later in 2000, Cormier-Daire et al. reported seven patients with genital anomalies (scrotal hypoplasia and cryptorchidism in the boys and clitoral hypertrophy in the girls), facial dysmorphism, kidney anomalies, absent patellae, and severe mental retardation in the two survivors. The condition is now known as genitopatellar syndrome. See also
Say-Barber-Biesecker-Young-Simpson syndrome
KAT6B

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