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aspartylglucosaminuria

Friday 1 August 2008

Definition: Aspartylglucosaminuria (AGU) is a rare, autosomal recessive metabolic disorder caused by deficient activity of the enzyme N-aspartyl-beta-glucosaminidase.

After trisomy 21 and fragile X syndrome, this is the most frequent multiple congenital anomaly/mental retardation syndrome.

Aspartylglycosaminuria is most common in patients of Finnish ancestry, affecting about 2.5% to 3% of the population.

Clinical manifestations consist of psychomotor retardation, grotesque facial appearance, hepatosplenomegaly, ventral hernia and skeletal abnormalities. It is a member of Finnish disease heritage, a group of diseases or syndromes caused by mutation in a single gene characterized by higher frequency in Finland than the rest of the world.

Aspartylglucosaminidase (1-aspart-amido-beta-N-acetylglucosamine aminohydrase - E.C.3.5.1.26) is an enzyme which cleaves the N-acetyl-glucosamine-asparagine linkage of oligosaccharide chains in glycoprotein and glycopeptide metabolism, causes Aspartylglycosaminuria.

Laboratory

Biochemical tests show high urinary levels of aspartylglucosamine and low activity of aspartylglucosaminidase.