Hepatic methionine adenosyltransferase deficiency in a 31-year-old man.

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.     

Fever, frontal sinus mass, and CSF pleocytosis in a 44-year-old man

Intracranial complications arising from frontal sinusitis occur infrequently. However, they can progress with such rapidity that the clinical situation becomes far advanced before they are recognized. Radiographic imaging techniques may not be definitive early in the course of these complications. The infectious disease service was asked to evaluate a middle-aged man with acute global headache and nasal discharge for two weeks. CSF pleocytosis (3,600 WBC/mm3) was documented on lumbar puncture, and a dense mass was noted on sinus radiographs. At surgery, a large bony lesion was found extending from the right frontal sinus into the adjacent ethmoid sinus and nasal-frontal duct. The authors discuss the bacteriology, pathogenesis, and potentially serious intracranial and extracranial complications of frontal sinusitis which were considered during their evaluation of this patient.