Dennis J. Dietzen, PhD

Professor, Pathology & Immunology

Additional Titles

  • Professor, Pediatrics
  • Medical Director, Laboratory Services, St. Louis Children’s Hospital
  • Medical Director, Laboratory Services, Children’s Specialty Care Center


  • BS: Chemistry: Marian University, Indianapolis, IN (1986)
  • PhD: Biochemistry and Molecular Biology: Indiana University (1992)
  • Postdoctoral Research Fellowship: Washington University (1995)
  • Postdoctoral Fellowship, Clinical Chemistry: Washington University (1995)

Board Certifications

  • Diplomate, American Board of Clinical Chemistry, 1997


  • President, American Association for Clinical Chemistry, 2018
  • Miriam Reiner Award, AACC Capital Section, 2018
  • Roger L. Boeckx Lectureship, Children’s National Medical Center, 2013
  • Outstanding Contributions to Pediatric Clinical Chemistry, AACC, 2012

Clinical Interests

  • Pediatric Clinical Laboratory Medicine
  • Inborn Errors of Metabolism
  • Clinical Toxicology
  • Clinical Applications of Mass Spectrometry

Research Interests

My research activities focus on improving existing analytic diagnostic tools and expanding the repertoire of informative biomolecules available for disease detection in children. We have developed novel analytic tools for the detection of inborn errors of metabolism and drug exposure in children and continue to explore the value of broad metabolic profiling in conditions such as pre-eclampsia, intrauterine growth retardation, liver failure, and neonatal hypoglycemia.


Dietzen DJ, Weindel AL, Carayannopoulos MO, Landt M, Normansell ET, Reimschisel TE, Smith CH. Rapid comprehensive amino acid analysis by liquid chromatography/tandem mass spectrometry: comparison to cation exchange with post-column ninhydrin detection. Rapid Commun Mass Spectrom. 2008;22(22):3481-8.
Green RP, Hollander AS, Thevis M, Thomas A, Dietzen DJ. Detection of surreptitious administration of analog insulin to an 8-week-old infant. Pediatrics. 2010;125(5):e1236-40.
Odibo AO, Goetzinger KR, Odibo L, Cahill AG, Macones GA, Nelson DM, Dietzen DJ. First-trimester prediction of preeclampsia using metabolomic biomarkers: a discovery phase study. Prenat Diagn. 2011;31(10):990-4.
Oladipo OO, Weindel AL, Saunders AN, Dietzen DJ. Impact of premature birth and critical illness on neonatal range of plasma amino acid concentrations determined by LC-MS/MS. Mol Genet Metab. 2011;104(4):476-9.
Crews BO, Moore J, Dietzen DJ. Circulating intact parathyroid hormone is suppressed at 25-hydroxyvitamin D concentrations >25 nmol/L in children. J Pediatr Endocrinol Metab. 2014;27(7-8):657-60.
DeMarco ML, Dietzen DJ, Brown SM. Sweating the small stuff: adequacy and accuracy in sweat chloride determination. Clin Biochem. 2015;48(6):443-7.
Jiang X, Sidhu R, Mydock-McGrane L, Hsu FF, Covey DF, Scherrer DE, Earley B, Gale SE, Farhat NY, Porter FD, Dietzen DJ, Orsini JJ, Berry-Kravis E, Zhang X, Reunert J, Marquardt T, Runz H, Giugliani R, Schaffer JE, Ory DS. Development of a bile acid-based newborn screen for Niemann-Pick disease type C. Sci Transl Med. 2016;8(337):337ra63.
Dietzen DJ, Bennett MJ, Lo SF, Grey VL, Jones PM. Dried Blood Spot Reference Intervals for Steroids and Amino Acids in a Neonatal Cohort of the National Children’s Study. Clin Chem. 2016;62:1658-1667.
Dietzen DJ. Fifty shades of yellow. Clin Chem 2017;63:937-938.
Yarbrough ML, Briden KE, Mitsios JV, Weindel AL, Terrill CM, Hunstad DA, Dietzen DJ. Mass spectrometric measurement of urinary kynurenine-to-tryptophan ratio in children with and without urinary tract infection. Clin Biochem 2018;56:83-88.

Dionne Brierton
BJCIH Room 5800