Professor, Department of Molecular and Human Genetics
Director, Cytogenetics Laboratory

B.S. in Biology, New Asia College, The Chinese University of Hong Kong, 1966
Ph.D. in Biochemical Genetics, Indiana University School of Medicine, 1975
Postdoctoral Fellow and Instructor in Medicine, Harvard Medical School, 1979
M.B.A., Washington University, St. Louis, 1992

RESEARCH INTERESTS:

The primary focus of my research is to improve and enhance diagnostic precision. A secondary goal is to maximize the possibilities created by the recent gene discoveries using FISH technology (Fluorescent In Situ Hybridization). Diagnostic application of chromosome abnormalities such as prenatal diagnosis of chromosome abnormalities, exclusion of chromosomal mosaicism in amniotic fluid cultures, chromosome mosaicism in Chronic Villus Sampling, clinical application of FISH technologies, preimplantation genetic diagnosis and recently chromosomal microarray analysis (CMA), all are powerful diagnostic tools that become more vital to the medical community as our diagnostic accuracy improves.

The Medical Genetics Laboratories (MGL) Cytogenetics Laboratory has pioneered the development of FISH testing involving recent gene discoveries through either close collaboration with investigators at Baylor College of Medicine (BCM) or investigators from other institutions, thereby enabling our laboratories the means to better recognize and diagnose genomic abnormalities related to certain chromosome disorders.

We began to offer chromosomal microarray analysis using BAC based comparative genomic hybridization (CGH) in February 2004. The CMA chip includes probes for virtually all known microdeletion/duplication syndromes, pericentromeric and subtelomeric regions, as well probes for some single gene disorders that may occur due to gain or loss of large DNA segments. Probes distributed randomly along all chromosome arms are also included to identify any full trisomies. Therefore, with a single test, CMA will detect almost all of the disorders detected by standard multiple FISH tests and provide a major advance in the diagnosis of patients in which a genetic cause of disability is strongly suspected but not observed by traditional cytogenetic analysis.

Our array coverage has doubled every year. In 2007, we successfully transitioned our BAC-based array to an Oligo-emulated array which significantly increased the sensitivity for detection of DNA fragments from 200 Kb to less than 50 Kb size. In March 2008, we launched our 105K array allowing the interrogation of the entire genome, including all subtelomeric and pericentromeric regions and enriched coverage of greater than 271 defined disease loci to a resolution of about 30 Kb while excluding repetitive sequences through a combination of bioinformatics and computation.

SELECTED PUBLICATIONS:

1. Sahoo T, del Gaudio D, German JR, Shinawi M, Peters SU, Person RE, Garnica A, Cheung SW, Beaudet AL (2008). Prader-Willi phenotype caused by paternal deficiency for the HBII-85 C/D box small nucleolar RNA cluster. Nat. Genet. 40: 719-721.

2. Shinawi M, Erez A, Shardy DL, Lee B, Naeem R, Weissenberger G, Chinault AC, Cheung SW, Plon SE (2008). Syndromic thrombocytopenia and predisposition to acute myelogenous leukemia caused by constitutional microdeletions on chromosome 21q. Blood 112: 1042-1047.

3. Ben-Shachar S, Ou Z, Shaw CA, Belmont JW, Patel MS, Hummel M, Amato S, Tartaglia N, Berg J, Sutton VR, Lalani SR, Chinault AC, Cheung SW, Lupski JR, Patel A (2008). 22q11.2 distal deletion: a recurrent genomic disorder distinct from DiGeorge syndrome and velocardiofacial syndrome. Am. J. Hum. Genet. 82: 214-221.

4. Ou Z, Kang SH, Shaw CA, Carmack CE, White LD, Patel A, Beaudet AL, Cheung SW, Chinault AC (2008). Bacterial artificial chromosome-emulation oligonucleotide arrays for targeted clinical array-comparative genomic hybridization analyses. Genet. Med. 10: 278-289.

5. Cheung SW, Shaw CA, Scott DA, Patel A, Sahoo T, Bacino CA, Pursley A, Li J, Erickson R, Gropman AL, Miller DT, Seashore MR, Summers AM, Stankiewicz P, Chinault AC, Lupski JR, Beaudet AL, Sutton VR (2007). Microarray-based CGH Detects Chromosomal Mosaicism Not Revealed by Conventional Cytogenetics. Am. J. Med. Genet. 143: 1679-1686.

6. Berg JS, Brunetti-Pierri N, Peters SU, King S-H L, Fong C, Salamone J, Freedenberg D, Hannig VL, Prock LA, Miller DT, Raffalli P, Harris DJ, Erickson RP, Cunniff C, Clark GD, Blazo MA, Peiffer DA, Gunderson KL, Sahoo T, Patel A, Lupski JR, Beaudet AL, Cheung SW (2007). Speech delay and autism spectrum behaviors are frequently associated with duplication of the 7q11.23 Williams-Beuren syndrome region. Genet. Med. 9: 427-441.

7. Sahoo T, Cheung SW, Ward P, Darilek S, Patel A, Del Gaudio D, Kang S-H L, Lalani SR, Li J, McAdoo S, Burke A, Shaw CA, Stankiewicz P, Chinault C, Van den Veyver IB, Roa BB, Beaudet AL, Eng CM (2006). Prenatal diagnosis of chromosomal abnormalities using array-based comparative genomic hybridization. Genet. Med. 8: 719-727.

8. del Gaudia D, Fang P, Scaglia F, Ward PA, Craigen WJ, Glaze DG, Neul JL, Patel A, Lee JA, Irons M, Berry SA, Pursley AA, Grebe TA, Freedenberg D, Martin RA, Hsich GE, Khera JR, Friedman NR, Zoghbi HY, Eng CM, Lupski JR, Beaudet AL, Cheung SW, Roa BB (2006). Increased MECP2 gene copy number due to genomic duplication in neurodevelopmentally delayed males. Genet. Med. 8: 784-792.

9. Yatsenko SA, Cheung SW, Scott DA, Nowaczyk MJM, Tarnopolsky M, Naidu S, Bibat G, Patel A, Leroy JG, Scaglia F, Stankiewicz P, Lupski JR (2005). Deletion 9Q34.3 syndrome: Genotype-phenotype correlations and an extended deletion in a patient with Opitz C trigonocephaly. J. Med. Genet. 42: 328-335.

For more publications, see listing on Pub Med.

CONTACT INFORMATION:

Sau W Cheung, Ph.D., M.B.A.
Director, Cytogenetics Laboratory
Medical Genetics Laboratories
Baylor College of Medicine
One Baylor Plaza, MS NAB 2015
Houston, TX, 77030, U.S.A.

Phone: 713-798-4991
Fax: 713-798-3157
E-mail:

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