Hyperlysinemia Explained

Hyperlysinemia is an autosomal recessive^[2] metabolic disorder characterized by an abnormal increase of lysine in the blood, but appears to be benign.^[3] It is caused by mutations in AASS, which encodes α-aminoadipic semialdehyde synthase.^[4]

Hyperlysinemia is associated with ectopia lentis (a displacement or malposition of the eye's crystalline lens) in humans.^{[5] [6] [7]}

Signs and symptoms

While hyperlysinemia typically causes no health problems, patients may exhibit behavioral abnormalities, delayed speech and language development, infantile hypotonia, intellectual disability, microcephaly, neurodevelopmental delay, psychomotor retardation, seizures, short attention spans, and short stature.^[8]

Genetics

Hyperlysinemia is inherited in an autosomal recessive manner.^[2] This means the defective gene responsible for the disorder is located on an autosome, and two copies of the defective gene (one inherited from each parent) are required in order to be born with the disorder. The parents of an individual with an autosomal recessive disorder both carry one copy of the defective gene, but usually do not experience any signs or symptoms of the disorder.

See also

• Saccharopinuria

Notes and References

1. Web site: Hyperlysinemia Genetic and Rare Diseases Information Center (GARD) – an NCATS Program . 16 April 2019 . rarediseases.info.nih.gov.
2. Sacksteder KA, Bier BJ, Morrell JC, Goodman BK, Geisbrecht BV, Cox RP, Gould SJ, Geraghty MT . June 2000 . Identification of the alpha-aminoadipic semialdehyde synthase gene, which is defective in familial hyperlysinemia . American Journal of Human Genetics . 66 . 6 . 1736–1743 . 10.1086/302919 . 1378037 . 10775527.
3. Dancis . J . Hutzler J . Ampola MG . Shih VE . van Gelderen HH . Kirby LT . Woody NC . May 1983 . The prognosis of hyperlysinemia: an interim report . Am J Hum Genet . 35 . 3 . 438–442 . 1685659 . 6407303.
4. Houten SM, Te Brinke H, Denis S, Ruiter JP, Knegt AC, de Klerk JB, Augoustides-Savvopoulou P, Häberle J, Baumgartner MR, Coşkun T, Zschocke J, Sass JO, Poll-The BT, Wanders RJ, Duran M . Apr 9, 2013 . Genetic basis of hyperlysinemia . Orphanet J Rare Dis . 8 . 57 . 10.1186/1750-1172-8-57 . 3626681 . 23570448 . free.
5. Web site: Eifrig . Charles W . 10 March 2015 . Ectopia Lentis Clinical Presentation: Causes . 9 December 2015 . Medscape . WebMD LLC.
6. Book: Basak, Samar K. . Atlas of clinical ophthalmology . 2013 . Jaypee brothers . 9789350903254 . Second . New Delhi . 231.
7. Book: Kaiser, Neil J. Friedman, Peter K. . Case reviews in ophthalmology . 2012 . Saunders Elsevier . 9781437726138 . Edinburgh . 184.
8. Web site: Hyperlysinemia . 21 February 2023 . Genetics and Rare Diseases Information Center . en.