Current Environment:

Research Overview

We are studying patients with Angelman syndrome (AS), a developmental disorder that affects movement, speech and social behavior, and investigating interventions that could potentially improve the care of patients with this condition. AS is caused by a deficiency of a maternally-expressed gene and is manifested at birth. Symptoms may include, but are not limited to, functionally severe developmental delay, speech impairments, movement or balance problems, and behavioral uniqueness, including a combination of frequent laughter or smiling, apparent happy demeanor, easily excitable personality, hand flapping movements and short attention span.

Current Projects:

Characterization of Angelman syndrome

We are conducting an observational study, following children with AS over 5 to 10 years to gain a better understanding of disease progression and the clinical features of AS's four molecular subclasses. The study will also attempt to establish genotype-phenotype correlations, which might aid in clinical care of AS patients.

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A trial of levodopa in Angelman syndrome

Levodopa is a drug commonly used in adults with Parkinson disease to control tremors and involuntary movements. Levodopa is not FDA-approved for use in children, but many children have used this drug for a variety of medical conditions over the last 30 years. Parents who put their children with AS on levodopa have reported improvements in cognition and abnormal movements, but the drug has not been rigorously studied in AS. Therefore, the goal of this study is to understand the efficacy of levodopa in these children.

Angelman syndrome clinical research studies

Gene identification for rare Mendelian disorders in collaboration with various basic science laboratories Clinical trials in rare Mendelian disorders

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Research Background

Dr. Tan is a clinical geneticist with an interest in a broad range of rare and ultra-rare Mendelian disorders, including pediatric cancer predisposition syndromes. He is also interested in the design of clinical trials for rare genetic syndromes. After graduating from medical school in Nottingham (United Kingdom), he undertook training in pediatrics and clinical genetics in Nottingham, Bury St. Edmunds, Cambridge (Cambridgeshire), and Boston. He has been on the faculty at Boston Children’s Hospital since 2006 and has been actively involved in clinical research studies on Angelman syndrome since then. He leads the Boston site of the Angelman Syndrome Natural History study and was the overall principal investigator of a multi-center phase II/III clinical trial of levodopa in Angelman syndrome.

He is also interested in Bohring-Opitz syndrome and serves on the Medical Advisory Board of the Bohring- Opitz Syndrome Foundation.

In addition, he now serves as the site PI of a gene therapy trial in adults with ornithine transcarbamylase deficiency.

Selected Publications

  1. Tan WH, Bacino CA, Skinner SA, Anselm I, Barbieri-Welge R, Bauer-Carlin A, Beaudet AL, Bichell TJ, Gentile JK, Glaze DG, Horowitz LT, Kothare SV, Lee HS, Nespeca MP, Peters SU, Sahoo T, Sarco D, Waisbren SE, Bird LM. Angelman syndrome: Mutations influence features in early childhood. Am J Med Genet A. 2011; 155A(1):81-90.
  2. Bird LM, Tan WH, Bacino CA, Peters SU, Skinner SA, Anselm I, Barbieri-Welge R, Bauer-Carlin A, Gentile JK, Glaze DG, Horowitz LT, Mohan KN, Nespeca MP, Sahoo T, Sarco D, Waisbren SE, Beaudet AL. A therapeutic trial of pro-methylation dietary supplements in Angelman syndrome. Am J Med Genet A. 2011; 155A(12):2956-63.
  3. Tan WH, Bird LM, Thibert RL, Williams CA. If not Angelman, what is it? A review of Angelman-like syndromes. Am J Med Genet A. 2014; 164A(4):975- 92.
  4. von Oettingen JE, Tan WH, Dauber A. Skeletal dysplasia, global developmental delay, and multiple congenital anomalies in a 5 year-old boy – Report of the second family with B3GAT3 mutation and expansion of the phenotype. Am J Med Genet A. 2014; 164A(6):1580-6.
  5. Smpokou P, Fox VL, Tan WH. PTEN hamartoma tumour syndrome: early tumour development in children. Arch Dis Child. 2015; 100(1):34-7.
  6. Tan WH, Bird LM. Angelman syndrome: Current and emerging therapies in 2016. Am J Med Genet C Semin Med Genet. 2016 Nov 8. doi: 10.1002/ajmg.c.31536. [Epub ahead of print]
  7. Bird LM, Tan WH. Treatment of genetic disorders-A vision coming into focus. Am J Med Genet C Semin Med Genet. 2016 Nov 3. doi: 10.1002/ajmg.c.31535. [Epub ahead of print]
  8. Lamont RE, Tan WH, Innes AM, Parboosingh JS, Schneidman-Duhovny D, Rajkovic A, Pappas J, Altschwager P, DeWard S, Fulton A, Gray KJ, Krall M, Mehta L, Rodan LH, Saller DN Jr, Steele D, Stein D, Yatsenko SA, Bernier FP, Slavotinek AM. Expansion of phenotype and genotypic data in CRB2-related syndrome. Eur J Hum Genet. 2016 Oct;24(10):1436-44.

Publications