2003 Volume 32 Issue 3 Pages 255-259
ALT (alanine aminotransferase) is a typical serum enzyme used for clinical diagnosis of hepatic diseases. We analyzed the ALT gene of a patient whose serum showed extremely low activity. The ALT gene analysis showed a homozygous missense mutation from cytosine (C) to adenine (A) at 2297, which had resulted in a replacement of proline (CCG) with threonine (ACG) at 351 (Pro351Thr). Because the missense mutation was not detected in healthy individuals (n=98) by RFLP (restriction fragment length polymorphism), it may be concluded that the missense mutation is not a polymorphism. ALT of the patient as detected in serum by Western blotting was approximately the same as that in a healthy individual, suggesting that the mutated molecule of Pro351Thr has no ALT activity.
