Thomas B. Friedman, Ph.D.

Senior Investigator

Section on Human Genetics


Porter Neuroscience Research Center, Room 1F-141
35 Convent Drive
Bethesda, MD 20892


Research Topics

The goal of our laboratory is to identify and characterize the molecular machines and pathways necessary for the development and maintenance of the inner ear. For the past 20 years, we have contributed to the understanding of the exquisite anatomical and physiological complexity of the inner ear by identifying many of the defective genes causing deafness ("deafness genes") in humans and by studying their biological functions in animal models. We continue to ascertain large families segregating deafness in order to identify novel deafness chromosomal loci and genes.

The five interrelated research goals of the Section on Human Genetics are:

  • Ascertain large families segregating deafness.
  • Map genes for inherited forms of human syndromic and nonsyndromic deafness.
  • Identify mutant genes associated with deafness using whole exome and genome sequencing.
  • Engineer animal models that mimic human deafness to access pathophysiology.
  • Reveal the pathophysiology and wild type functions of "deafness genes."

Improved understanding of the mutated genes will provide important information on hearing and brain processing. The identification of the relevant genes will also permit early and more accurate diagnosis for certain forms of hereditary hearing and communication impairments.


Dr. Friedman received a B.S. and his Ph.D. from the University of Michigan where he worked with Tahir Mohammed Rizki on the molecular genetics of purine metabolism in Drosophila. After postdoctoral work (studying galactosemia in humans) at the National Institute of Mental Health, he became a faculty member in the Department of Zoology and the Department of Pediatrics and Human Development at Michigan State University. For five years he was also the Director of the Interdepartmental Graduate Program in Genetics. In 1996, he joined NIDCD as the Chief, Laboratory of Molecular Genetics. Dr. Friedman's Section on Human Genetics at the NIDCD studies hereditary hearing loss and Usher Syndrome in humans and mouse models. His laboratory also studies the functions (cell biology and biochemistry) of proteins encoded by genes associated with deafness.

Selected Publications

  1. Nakano Y, Kelly MC, Rehman AU, Boger ET, Morell RJ, Kelley MW, Friedman TB, Bánfi B. Defects in the Alternative Splicing-Dependent Regulation of REST Cause Deafness. Cell. 2018;174(3):536-548.e21.
  2. Bird JE, Takagi Y, Billington N, Strub MP, Sellers JR, Friedman TB. Chaperone-enhanced purification of unconventional myosin 15, a molecular motor specialized for stereocilia protein trafficking. Proc Natl Acad Sci U S A. 2014;111(34):12390-5.
  3. Bird JE, Barzik M, Drummond MC, Sutton DC, Goodman SM, Morozko EL, Cole SM, Boukhvalova AK, Skidmore J, Syam D, Wilson EA, Fitzgerald T, Rehman AU, Martin DM, Boger ET, Belyantseva IA, Friedman TB. Harnessing molecular motors for nanoscale pulldown in live cells. Mol Biol Cell. 2017;28(3):463-475.
  4. Drummond MC, Barzik M, Bird JE, Zhang DS, Lechene CP, Corey DP, Cunningham LL, Friedman TB. Live-cell imaging of actin dynamics reveals mechanisms of stereocilia length regulation in the inner ear. Nat Commun. 2015;6:6873.
  5. Kitajiri S, Sakamoto T, Belyantseva IA, Goodyear RJ, Stepanyan R, Fujiwara I, Bird JE, Riazuddin S, Riazuddin S, Ahmed ZM, Hinshaw JE, Sellers J, Bartles JR, Hammer JA 3rd, Richardson GP, Griffith AJ, Frolenkov GI, Friedman TB. Actin-bundling protein TRIOBP forms resilient rootlets of hair cell stereocilia essential for hearing. Cell. 2010;141(5):786-98.

Related Scientific Focus Areas

This page was last updated on Thursday, August 18, 2022