Lab Expertise

More than 34 years of training and experience in Clinical Chemistry with an emphasis on Pediatric Laboratory Medicine. Trained initially as an enzymologist. Skilled in the development of methods for the measurement of metabolic intermediates for the diagnosis of inherited metabolic diseases using all forms of mass spectrometry.

Clinical Expertise

Has directed full service clinical chemistry and specialized metabolic disease laboratories

Dr. Bennett's research focuses upon the pathway of mitochondrial fatty acid oxidation and upon the diagnosis of patients with genetic defects of this pathway. Little is known about the intramitochondrial organization of the proteins involved in this important pathway of metabolic response to increased energy demand. Specific focus is being placed on protein interactions that are responsible for the structural integrity and activation of the enzymes of fatty acid oxidation. It is anticipated that novel genetic defects related to non-enzymatic components of a fatty acid metabolome will be identified from a cohort of patients in whom fatty acid oxidation is impaired but in whom all known enzymes are genetically intact. A second area of research is in the severe recessively inherited neurodegenerative disease; Neuronal Ceroid-Lipofuscinosis type 3 (CLN3, Batten disease). Despite the gene being cloned 10 years ago, the pathogenesis of this untreatable disease remains unknown. The lab has recently defined the protein encoded by the cLN3 gene as a lipid raft resident and is currently studying interactions within the membranes to determine its function.

Education and Training

Board Certification

Clinical Chemistry – American Board of Clinical Chemistry

Undergraduate Degree

BSc in Physiology & Biochemistry - University of Reading, Reading, UK

Graduate Degree

Fellowship - United Sheffield Hospital, Sheffield, UK
FRCPath - Royal College of Pathologists, London, UK

Additional Training

PhD - University of Sheffield School of Medicine, Sheffield, UK

Titles and Academic Titles


Evelyn Willing Bromley Endowed Chair in Clinical Laboratories and Pathology

Professor of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine

Research Interests

Pathophysiology of inherited diseases of mitochondrial fatty acid oxidation
Mechanisms of neuronal death in the neuronal ceroid-lipofuscinoses, a group of severe inherited neurodegenerative diseases




Chen J, Meng C-K, Narayan SB, Luan W, Bennett MJ. The use of deconvolution reporting software and backflush improves the speed and accuracy of data processing for urinary organic acid analysis. Clin Chim Acta 2009 Jul;405(1-2):53-9. Epub 2009 Apr 16.

Loughrey C, Bennett MJ. Screening for MCAD deficiency in newborns. Editorial Brit Med J 338: 843-4, 2009.


Palladino AA, Bennett MJ, Stanley CA. Hyperinsulinism in infancy and childhood: when an insulin level is not always enough. Clin Chem 54:256-263, 2008.

Filling C, Keller B, Hirschberg D, Marschall H-U, Jornvall H, Bennett MJ, Oppermann U. Role of short-chain hydroxyacyl CoA dehydrogenases in SCHAD deficiency. Biochem Biophys Res Commun 368:6-11, 2008.

Jethva R, Bennett MJ, Vockley G. Short-chain acyl-coenzyme A dehydrogenase deficiency. Mol Genet Metab 95:195-200, 2008.

Sherman EA, Strauss KA, Tortorelli S, Bennett MJ, Knerr I, Morton DH, Puffenberger EG. Genetic mapping of glutaric aciduria, type 3, to chromosome 7 and identifications of mutations in C7orf10. Amer J Hum Genet 84:604-609, 2008.

Bennett MJ, Dietzen DJ, Rinaldo P, Garg U, Whitley RJ, LO SF, Rhead WJ, Hannon WH. Follow-up testing for metabolic diseases identified by expanded newborn screening using tandem mass spectrometry. A Laboratory Medicine Practice Guideline of the National Academy of Clinical Biochemistry.


Freeto S, Mason D, Chen J, Scott RH, Narayan SB, Bennett MJ. A rapid ultra performance liquid chromatography (UPLC tandem mass spectrometric method for measuring amino acids associated with maple syrup urine disease, tyrosinemia and phenylketonuria. Ann Clin Biochem 44:474-481, 2007.

Rakheja D, Narayan S, Bennett MJ. Juvenile neuronal ceroid-lipofuscinosis (Batten disease): a brief review and update. Curr Mol Med 7:603-608, 2007.


Narayan SB, Rakheja D, Tan L, Pastor JV, Bennett MJ. CLN3P, the Batten disease protein, is a novel palmitoyl-protein D-9 desaturase. Ann Neurol 60:570-577, 2006.