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High Serum Gamma-Glutamyltransferase Concentrations in a Family

N Engl J Med 1994; 330:1832-1833June 23, 1994

Article

To the Editor:

Gamma-glutamyltransferase (GGT) is a glycoprotein enzyme that catalyzes the transfer of the gamma-glutamyl group from gamma-glutamyl peptides to other peptides and to l-amino acids. The activity of GGT in the kidney is very high; there is lower activity in the liver and pancreas. Patients with cholestasis usually have increased serum GGT concentrations, and the concentrations may be increased by certain enzyme-inducing drugs or alcohol abuse1-3. Measurements of serum GGT aid in interpreting elevated serum alkaline phosphatase values, since patients with skeletal disease have normal serum GGT values. GGT activity in serum is the sum of the activities of heterogeneous isoenzymes that migrate in zone electrophoresis, as follows: GGT-1 to the prealbumin-albumin region, GGT-2 to the alpha-globulin region, GGT-3 to the alpha-globulin region, and GGT-4 to the beta globulin region4,5.

We describe a family in which a number of members had high serum GGT concentrations (Figure 1Figure 1Serum GGT Concentrations in a Family with an Isolated Elevation of the Enzyme.), as measured by a photoenzymatic method (normal values, 0 to 50 U per liter). The proband was identified by routine testing. No family member had a history of drug use, alcohol abuse, or any form of viral hepatitis, and all the family members studied were healthy and had normal results on other liver-function tests. The GGT elevations were in the GGT-2 fraction. The inheritance seems to be predominantly autosomal dominant. These results indicate that high serum GGT concentrations do not always indicate the presence of hepatobiliary disease.

Michele Bibas, M.D.
Germano Zampa, M.D.
Alberto Procopio, M.D.
Ospedale San Giacomo, 00186 Rome, Italy

Roberto Guaitolini, M.D.
Ospedale San Camillo, 00154 Rome, Italy

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Citing Articles (1)

Citing Articles

1. 1

   Alfonso Pompella, Michele Emdin, Claudio Passino, Aldo Paolicchi. (2004) The significance of serum γ-glutamyltransferase in cardiovascular diseases. Clinical Chemistry and Laboratory Medicine 42:10, 1085-1091
   CrossRef