Disease relevance of Hyperlysinemias

• A 7-year-old boy with speech delay, hyperactive behavior, and minor neurologic abnormalities had been found in the past to have "intermittent cystinuria." A more detailed investigation revealed hyperlysinemia and hyperlysinuria, with lesser increases in urinary excretion of arginine and cystine [1].
• The oral loading tests of L-lysine revealed hyperammonemia, hyperlysinemia, hyperargininemia, hypercitrullinemia and homocitrullinuria [2].

High impact information on Hyperlysinemias

• Biochemical studies revealed hyperlysinemia, hypocarnitinemia, normal organic acid profile, and an unusual acylcarnitine species in both urine and blood [3].
• On the basis of these and other results, we propose that AASS catalyzes the first two steps of the major lysine-degradation pathway in human cells and that inactivating mutations in the AASS gene are a cause of hyperlysinemia [4].
• Identification of the alpha-aminoadipic semialdehyde synthase gene, which is defective in familial hyperlysinemia [4].
• A normal child has been born to a mother with hyperlysinemia, indicating that the fetus may develop normally despite exposure to high lysine levels [5].
• It is suggested that familial hyperlysinemia, type I, be applied to patients with major defects in lysine-ketoglutarate reductase and saccharopine dehydrogenase, and that familial hyperlysinemia, type II, to be used to designate patients in whom significant amounts of lysine-ketoglutarate reductase are retained [6].

Chemical compound and disease context of Hyperlysinemias

• The relation of the two genetic entities involving lysine degradation, familial hyperlysinemia and saccharopinuria, is discussed [6].
• To complete the studies on the enzymes associated with familial hyperlysinemia, saccharopine oxidoreductase was partially purified from human liver and characterized [6].
• Serum citrulline levels were approximately 10 times higher than control level and lysine levels were within the normal range, in contrast to the classical form of the disease in which serum citrulline is approximately 100 times normal levels and hyperlysinemia is usually present [7].

Gene context of Hyperlysinemias

• Propionic acidemia and hyperlysinemia in a case with ornithine transcarbamylase (OTC) deficiency [8].

References