-transparent.png){kind=logo}
A 31-year-old man with hepatic methionine adenosyltransferase (MAT) deficiency was evaluated for an odd odor to his breath. He had no other symptoms. Plasma methionine was 716 microM (normal, 15-40 microM), and plasma methionine-oxidation products were 460 microM (normal, 0). Hepatic MAT activity was 28% of normal. Unlike the control human enzyme, the patient's residual MAT activity was not stimulated by 10% dimethylsulfoxide and the velocity was not increased by high substrate concentration; at 1.0 mM methionine, the patient's MAT activity was only 7% of normal. These biochemical findings are consistent with a deficiency of the high-Km isoenzyme of MAT. Despite this enzyme deficiency, liver histology and clinical tests of hepatic and other organ function were normal. The patient, who is 25 years older than the oldest reported individual with MAT deficiency, provides evidence that partial MAT deficiency is a benign disorder and that chronic hypermethioninemia (less than 1 mM) is not by itself detrimental to health.
W A Gahl, and
J D Finkelstein, and
K D Mullen, and
I Bernardini, and
J J Martin, and
P Backlund, and
K G Ishak, and
J H Hoofnagle, and
S H Mudd
January 2000,
Pharmacology & therapeutics,
W A Gahl, and
J D Finkelstein, and
K D Mullen, and
I Bernardini, and
J J Martin, and
P Backlund, and
K G Ishak, and
J H Hoofnagle, and
S H Mudd
July 2004,
Clinical orthopaedics and related research,
W A Gahl, and
J D Finkelstein, and
K D Mullen, and
I Bernardini, and
J J Martin, and
P Backlund, and
K G Ishak, and
J H Hoofnagle, and
S H Mudd
April 1979,
Biochemical medicine,
W A Gahl, and
J D Finkelstein, and
K D Mullen, and
I Bernardini, and
J J Martin, and
P Backlund, and
K G Ishak, and
J H Hoofnagle, and
S H Mudd
June 2021,
Chest,
W A Gahl, and
J D Finkelstein, and
K D Mullen, and
I Bernardini, and
J J Martin, and
P Backlund, and
K G Ishak, and
J H Hoofnagle, and
S H Mudd
September 2016,
International journal of dermatology,
W A Gahl, and
J D Finkelstein, and
K D Mullen, and
I Bernardini, and
J J Martin, and
P Backlund, and
K G Ishak, and
J H Hoofnagle, and
S H Mudd
February 2008,
Revista clinica espanola,
W A Gahl, and
J D Finkelstein, and
K D Mullen, and
I Bernardini, and
J J Martin, and
P Backlund, and
K G Ishak, and
J H Hoofnagle, and
S H Mudd
March 2012,
Molecular genetics and metabolism,
W A Gahl, and
J D Finkelstein, and
K D Mullen, and
I Bernardini, and
J J Martin, and
P Backlund, and
K G Ishak, and
J H Hoofnagle, and
S H Mudd
July 2023,
Brain pathology (Zurich, Switzerland),
W A Gahl, and
J D Finkelstein, and
K D Mullen, and
I Bernardini, and
J J Martin, and
P Backlund, and
K G Ishak, and
J H Hoofnagle, and
S H Mudd
September 2007,
Chest,
W A Gahl, and
J D Finkelstein, and
K D Mullen, and
I Bernardini, and
J J Martin, and
P Backlund, and
K G Ishak, and
J H Hoofnagle, and
S H Mudd
January 1984,
Investigative radiology,
