Background
BSc (Hons), National University of Singapore , 1986
MSc, University of British Columbia ( Vancouver , Canada ), 1989
PhD, Baylor College of Medicine ( Houston , Texas , USA ), 1994
Diplomate, American Board of Medical Genetics (dipABMG), 1999
Fellow, American College of Medical Genetics (FACMG), 2000

Major Research Interests
Genetics of Craniofacial Disorders
The head is anatomically the most complex part of the vertebrate body, and a synthesis of embryology, evolution, and genetics is shaping our understanding of normal craniofacial development as well as craniofacial malformations. Oral clefts are a complex and heterogeneous group of birth defects that represent a major public health burden because of their high prevalence among newborns and the medical and economic burden they create for both affected infants and their families. The etiology of oral clefts remains enigmatic despite strong evidence that both genetic and environmental factors must be involved. It is likely that multiple genes control risk to oral clefts, some of which may interact with common environmental risk factors such as maternal smoking, alcohol consumption, and vitamin supplementation. We are part of an international collaborative effort to collect information on isolated, non-syndromic cleft lip with or without cleft palate (CL/P) cases and their families to test a number of candidate genes using the case-family design. Through this effort, we hope to identify genes exerting moderate to strong effects on risk to CL/P.
Our laboratory is also interested in studying candidate craniofacial genes in the zebrafish Danio rerio, a rapidly emerging model system for embryological, genetic/genomic, cellular/biochemical and other functional studies. A major advantage of the zebrafish is its rapid, external, and visually transparent embryonic development, which greatly simplifies analysis of embryonic morphogenesis and identification of developmental malformations. We are characterizing candidate craniofacial development/malformation genes using a combination of genomic and functional strategies, assisted by transposon-mediated transgenesis and insertional mutatgenesis technologies.

Novel Molecular Diagnostic Technologies
Another interest of our group has been in applying modern molecular tools to develop novel diagnostic tests for common genetic disorders such as a - and b -thalassemia and fragile X syndrome. We recently developed a simple single-tube multiplex-PCR assay to detect the seven most common deletional determinants of a -thalassemia (-- SEA, -- FIL, -- THAI, -- MED, -( a ) 20.5, - a 3.7 , and - a 4.2 ), which accounts for greater than 90% of all a -thalassemia mutations. To complement this multiplex PCR test, are in the process of developing simplified non-isotopic tests to detect the most common Southeast Asian a - and b -thalassemia point mutations based on minisequencing technology. A single cell molecular test for the -- SEA determinant of a -thalassemia is also being developed for application to preimplantation genetic diagnosis, an emerging alternative form of prenatal diagnosis that involves biopsy of single blastomeres from 8-10 cell stage embryos obtained by IVF/ICSI, followed by molecular analysis of the isolated blastomeres. For fragile X syndrome, the most common inherited mental retardation and second most common 'chromosomal' cause of mental impairment, we are exploring various genomic modification and FISH based strategies to develop a simple and reproducible test to detect the causative FMR1 gene CGG repeat hyperexpansion in both males and females.