adenosine kinase deficiency

Four inborn errors of metabolism (IEMs) are known to cause hypermethioninemia by directly interfering with the methionine cycle.

Hypermethioninemia is occasionally discovered incidentally, but it is often disregarded as an unspecific finding, particularly if liver disease is involved. In many individuals the hypermethioninemia resolves without further deterioration, but it can also represent an early sign of a severe, progressive neurodevelopmental disorder.

ADK deficiency is a previously undescribed, severe inborn error of metabolism shedding light on a functional link between the methionine cycle and adenosine metabolism.

See also

 S-adenosylhomocysteine hydrolase (SAHH) deficiency, which causes a similar biochemical phenotype.

References

 Adenosine kinase deficiency disrupts the methionine cycle and causes hypermethioninemia, encephalopathy, and abnormal liver function. Bjursell MK, Blom HJ, Cayuela JA, Engvall ML, Lesko N, Balasubramaniam S, Brandberg G, Halldin M, Falkenberg M, Jakobs C, Smith D, Struys E, von Döbeln U, Gustafsson CM, Lundeberg J, Wedell A. Am J Hum Genet. 2011 Oct 7;89(4):507-15. PMID: 21963049