Moolenaar et al. (1999) described a 38-year-old man of African ancestry who was in good health and had normal intelligence. However, he complained of an abnormal body odor, which resembled the odor of fish, since the age of ... Moolenaar et al. (1999) described a 38-year-old man of African ancestry who was in good health and had normal intelligence. However, he complained of an abnormal body odor, which resembled the odor of fish, since the age of 5 years. The fish odor had led to severe psychologic and professional problems and increased under stress and effort. Furthermore, the patient complained of unusual muscular fatigue. Plasma creatine kinase was consistently approximately 4-fold higher than the upper limit of the reference interval. Routine clinical chemical and hematologic determinations, including serum cobalamin and urea, were unremarkable. In addition, plasma folate and homocysteine were within the normal range. Analysis of very long chain fatty acids and a carnitine ester profile were normal, as were the results of amino acid and organic acid analyses of blood and urine. The brothers, sisters, and 2 sons of the patient were without signs or symptoms. Moolenaar et al. (1999) used nuclear magnetic resonance (NMR) spectroscopy to study serum and urine from the patient. The concentration of N,N-dimethylglycine (DMG) was increased approximately 100-fold in serum and 20-fold in urine. The presence of DMG as a storage product was confirmed by use of NMR spectroscopy and gas chromatography-mass spectrometry. The high concentration of DMG was caused by a deficiency of the enzyme dimethylglycine dehydrogenase. This deficiency was the first inborn error of metabolism discovered by use of in vitro NMR spectroscopy of body fluids. Moolenaar et al. (1999) concluded that DMGDH deficiency must be added to the differential diagnosis of patients complaining of fish odor.
In a patient with deficiency of dimethylglycine dehydrogenase, Moolenaar et al. (1999) identified homozygosity for a missense mutation in the DMGDH gene (605849.0001).