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Siskin Children's Institute

Medical & behavioral Health Team


MEdical Providers


james van decar, Md, FAAP

Dr. Van Decar is a neurodevelopmental pediatrician with more than 30 years of experience serving children with special needs and is an expert in the evaluation, diagnosis, and management of developmental disabilities in children. He retired from the Air Force in 2015 after a 28-year career spanning medical school at the Uniformed Services University of the Health Sciences in Bethesda, Maryland, residency in pediatrics and fellowship in developmental disabilities in San Antonio, Texas, and then multiple assignments including Lakenheath Air Force Base in England, Wright Patterson Air Force Base in Ohio, and Eglin Air Force Base in Florida. 

In addition to the exceptional care he provided to thousands of military dependent children with special needs, he also established one of the Department of Defense (DoD)’s first early intervention programs for children when their families were stationed overseas. He advocated for them through efforts to reform the DoD’s Exceptional Family Member Program, and worked to improve Tricare’s Autism Demonstration Program. Dr. Van Decar is a member of the planning committee for the American Academy of Pediatrics Developmental Pediatrics board review course, and also consults with the Florida State University Autism Center.  In addition, he was recently appointed by the Governor of Tennessee to the State Interagency Coordinating Council for Early Intervention Services.


Stephanie Klees, Md, MS, FAAP

Dr Klees is a developmental behavioral pediatrician with over 15 years of pediatric experience serving children with special needs both domestically and abroad. Dr Klees graduated with a medical degree from the State University of New York at Stony Brook in 2003 and completed her pediatric residency at Children’s Hospital Oakland in Oakland, California in 2006. She was a National Health Service Corps Scholar and worked for 2 years at a community health center in St Louis, Missouri to fulfill her commitment. She has been board certified in General Pediatrics since 2006 and worked for many years as a primary care physician in various communities including St Louis, Birmingham, AL, Fremont, CA and Boston, MA. She obtained a Master’s degree in Global Health Sciences at UCSF in 2013 and then worked as Yale University faculty for the Human Resources for Health partnership with the Rwanda Ministry of Health where she had the privilege of working with Rwandan pediatricians to help strengthen the pediatric residency program there. Most recently, Dr Klees completed a three-year fellowship in Developmental Behavioral Pediatrics at Hasbro Children’s Hospital/Brown University in Rhode Island.  

Dr. Klees feels privileged to work with children with developmental differences, learning difficulties, and behavioral concerns.  She is passionate about working collaboratively with families, other healthcare providers, and schools to find ways to maximize children's developmental potential. 

Applied Behavior Analysis


Alyssa Harris, BCBA

Alyssa is a Board Certified Behavior Analyst and TN Licensed Behavior Analyst and from Cookeville, TN. She earned a bachelor’s degree in Psychology and a master’s degree in Special Education from Tennessee Tech University. She completed her coursework in Applied Behavior Analysis though Florida Institute of Technology.

Alyssa has provided ABA Therapy services to individuals with autism of all age groups in the home, community, and school settings. Alyssa is passionate about educating families about the importance of ABA Therapy.