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Thomas B. Friedman, Ph.D.

+1 301 496 7882
+1 301 402 7580
Thomas B. Friedman, Ph.D.

Chief, Laboratory of Molecular Genetics 
Chief, Section on Human Genetics

Dr. Friedman received a B.S. and 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 the NIDCD as the chief, Laboratory of Molecular Genetics. Dr. Friedman's Section on Human Genetics at the NIDCD studies hereditary hearing loss in humans and animal models. His laboratory also studies the functions (cell biology and biochemistry) of proteins encoded by genes associated with deafness.

Dr. Friedman served as the acting scientific director of the NIDCD from June 6, 2020 to April 10, 2021.


Laboratory of Molecular Genetics

Scientific Areas:

Molecular genetics of hereditary deafness

Selected Publications

Adeyemo A, Faridi R, Chattaraj P, Yousaf R, Tona R, Okorie S, Bharadwaj T, Nouel-Saied LM, Acharya A, Schrauwen I, Morell RJ, Leal SM, Friedman TB, Griffith AJ, Roux I. Genomic analysis of childhood hearing loss in the Yoruba population of Nigeria. Eur J Hum Genet. 2021 Nov 26. doi: 10.1038/s41431-021-00984-w. Epub ahead of print. PMID: 34837038.

Sethna S, Zein WM, Riaz S, Giese AP, Schultz JM, Duncan T, Hufnagel RB, Brewer CC, Griffith AJ, Redmond TM, Riazuddin S, Friedman TB, Ahmed ZM. Proposed therapy, developed in a Pcdh15-deficient mouse, for progressive loss of vision in human Usher syndrome. Elife. 2021 Nov 9;10:e67361. doi: 10.7554/eLife.67361. PMID: 34751129; PMCID: PMC8577840.

Katsuno T, Belyantseva I, Cartagena-Rivera AX, Ohta K, Crump SM, Petralia RS, Ono K, Tona R, Imtiaz A, Rehman A, Kiyonari H, Kaneko M, Wang Y-X, Abe T, Ikeya M, Fenollar-Ferrer C, Riordan GP, Wilson EA, Fitzgerald TS, Segawa K, Omori K, Ito J, Frolenkov GI, Friedman TB, Kitajiri S-I. TRIOBP-5 sculpts stereocilia rootlets and stiffens supporting cells enabling hearing. JCI Insight. 2019 June 20.

Inside the inner ear of a mouse, arc-shaped hair cell bundles emerge from the surface of the membrane. Hair cells transform incoming sound vibrations into signals that can be picked up by the auditory nerve and translated in the brain as sound.

Cover of JCI Insight, 20 June 2019. Source: Inna Belyantseva, M.D, Ph.D., NIDCD

Fang Q, Indzhykulian AA, Mustapha M, Riordan GP, Dolan DF, Friedman TB, Belyantseva IA, Frolenkov GI, Camper SA, Bird JE. The 133-kDa N-terminal domain enables myosin 15 to maintain mechanotransducing stereocilia and is essential for hearing. eLIFE. 2015 Aug 24;4.

Cover of eLIFE: A Tale of Two Isoforms

Cover of eLIFE

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 Apr 21;6:6873.

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 Aug 26;111(34):12390-5.

Rehman AU, Santos-Cortez RL, Morell RJ, Drummond MC, Ito T, Lee K, Khan AA, Basra MA, Wasif N, Ayub M, Ali RA, Raza SI, University of Washington Center for Mendelian Genomics, Nickerson DA, Shendure J, Bamshad M, Riazuddin S, Billington N, Khan SN, Friedman PL, Griffith AJ, Ahmad W, Riazuddin S, Leal SM, Friedman TB. (2014) Mutations in TBC1D24, a gene associated with epilepsy, also cause nonsyndromic deafness DFNB86. Am J Hum Genet 2014 Jan 2;94(1):144-52. doi: 10.1016/j.ajhg.2013.12.004.

Graphic representation of TBC1D24 structure (left) and its encoded protein (right). DFNB86-associated mutations are shown above the diagram, and epilepsy-associated mutations are shown below.

Riazuddin S, Belyantseva, IA, Giese APJ., Kwanghyuk L, Indzhyukulian AA, Nandamuri SP, Yousaf R, Sinha GP, Lee S, Terrell D, Hegde RS, Ali RA, Anwar S, Andre-Elizondo PB, Sirmaci A, Parise LV, Basit S, Wali A, Ayub M, Ansar M, Ahmad W, Khan S, Akram J, Tekin M, Riazuddin Sh, Cook T, Buschbeck EK, Frolenkov G, Leal SM, Friedman TB, Ahmed ZM. (2012) Alterations of the CIB2 calcium-and integrin-binding protein cause Usher syndrome type 1J and nonsyndromic deafness DFNB4. Nature Genetics Volume 44: pages 1265-1271.

Rehman AU, Morell, RJ, Khan SY, Belyantseva IA, Boger ET, Shahzad M, Ahmed ZA, Riazuddin S, Khan SN, Friedman TB (2010) Targeted capture and next-generation sequencing identifies C9orf75, encoding TAPERIN, as the mutated gene in nonsyndromic deafness DFNB79. The American Journal of Human Genetics 86: 378-388.

Localization of TAPERIN at the base
(taper) of hair cell stereocilia in the mouse
inner ear. The American Journal of
Human Genetics 2010

Borck G, Rehman AU, Lee K, Pogoda, H-M, Kakar N, von Ameln S, Grillet N, Hildebrand MS, Ahmed ZM, Nürnberg G, Ansar M, Basit S, Javed Q,. Morell RJ, Nasreen NA, Shearer AE, Ahmad A, Kahrizi K, Shaikh RS, RA A, Khan SN, Goebel I, Meyer NC, Kimberling WJ, Webster JA, Stephan D, Schiller M, Bahlo M, Najmabadi H, Gillespie PG, Nürnberg P, Wollnik B, Riazuddin S, Smith RJH, Ahmad W, Müller U, Hammerschmidt M, Friedman TB, Riazuddin S, Leal SM, Ahmad J, Kubisch C (2011) Loss-of-Function Mutations of ILDR1 Cause Autosomal-Recessive Hearing Impairment DFNB42. The American Journal of Human Genetics 88: 1-11.

Kitajiri S, Sakamoto T, Belyantseva IA, Goodyear RJ, Stepanyan R, Fujiwara I, Bird JE, Riazuddin S, Ahmed ZM, Hinshaw JE, Sellers J, Bartles JR, Hammer JA, Richardson GP, Griffith AJ, Frolenkov GI, Friedman TB. Actin-Bundling Protein TRIOBP Forms Resilient Rootlets of Hair Cell Stereocilia Essential for Hearing. Cell, Volume 141, Issue 5, 786-798, 28 May 2010.

Cover of Cell

Cover of Cell May 2010

Belyantseva IA, Boger ET, Naz S, Frolenkov GI, Sellers JR, Ahmed ZM, Griffith AJ, Friedman TB. Myosin-XVa is required for tip localization of whirlin and differential elongation of hair-cell stereocilia. Nature Cell Biology 7(2):148–56, 2005.

Nature Cell Biology cover image

Cover of Nature Cell Biology 2005

Belyantseva IA, Boger ET, Friedman TB. Myosin XVa localizes to the tips of inner ear sensory cell stereocilia and is essential for staircase formation of the hair bundle. Proceedings of the National Academy of Sciences of the USA 100:13958–63, 2003.

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