Our Providers

Our physicians offer comprehensive care to infants, children, and adolescents that fosters their total growth, development, and health by incorporating the current recommendations of the American Academy of Pediatrics, along with the latest advances in pediatric health.  All physicians are board certified by the American Board of Pediatrics and are Fellows of the American Academy of Pediatrics. The group has 24 hour call coverage and both offices have in-house laboratories. If you have further questions regarding the practice, please call Jennifer Manis, RN, BSN, clinical manager at (303) 791-9999 and select option 1.


Highlands Ranch Office

  • Nicholas C. Kyriazi, MD, FAAP

    Dr. Nicholas Kyriazi was born and raised in Northern Virginia.  He attended the George Washington University for his undergraduate education, also participating in varsity swimming and water polo.  He attended GWU for medical school and completed his pediatric residency training at Childrens National Medical Center, primary care tract.  Professionally, he is in his 32nd year of private practice, 26+ years in Colorado and with Littleton Pediatric Medical Center.  He has been the recipient of the 5280 Magazine top doctor four times since 2017.  He is married to a Denver native, and they have six children, and four grandsons.  He loves Colorado and especially the mountains.  He is excited to take care of your child from birth through college!

  • Robert O. Gin, MD, FAAP

    Dr. Robert Gin obtained his undergraduate degree in Biomedical Engineering from the University of Southern California and his Doctor of Medicine from the University of California, Irvine.  He completed his Pediatric Residency at the UCLA School of Medicine.  Prior to practicing in Colorado, Dr. Gin practiced in California and Arizona.  He enjoys skiing, biking, traveling, and spending time with his wife, two children, and two playful dogs.

  • Maureen Snelling, MD, FAAP

    Dr. Maureen Snelling grew up in Philadelphia, Pennsylvania.  She graduated from Lafayette College with a degree in Biology.  After graduation, she worked for a brief time in pharmaceutical sales before going to medical school at the Medical College of Pennsylvania.  She completed her residency at the University of Maryland in Baltimore, Maryland.  She moved to Colorado in 2001.  Dr. Snelling has a daughter who keeps her on her toes with sports and her crazy school schedule.  In her free time, Dr. Snelling enjoys skiing, spending time with her family, and loves to travel to a beautiful beach.  

  • Karen Koto, DO, FAAP

    Dr. Karen Koto was born and raised in Denver.  She graduated with highest honors in Biology and a minor in Chemistry from Oberlin College in Ohio and attended medical school at Touro University College of Osteopathic Medicine in Vallejo, CA.  She did her pediatric residency training at St John's Episcopal Hospital and Wyckoff Heights Medical Center in New York City.  She practiced in Grants Pass, Oregon prior to moving back to Colorado.  Karen and her husband Rob have 2 daughters, Grace and Nora.  She enjoys cooking, traveling, and spending time with family.  She loves caring for children and watching them learn and grow.

Ken Caryl Office

  • Tamera Nelson, MD, FAAP

    Dr. Tamera Nelson was born and raised in North Dakota. She attended the University of North Dakota, earning first a BSN in Nursing and then attending Medical School. She did her pediatric residency at Children’s Mercy Hospital in Kansas City, Missouri and then spent 6 years working ER and Urgent Care for Children’s Mercy and then at The Children’s Hospital of Colorado. After years of shift work, she happily joined Littleton Pediatrics in 2012. She loves getting to see her patients grow and develop through the years while guiding parents through the ups and downs along the way. She enjoys travel, cooking, reading, and hiking with her husband and dogs.

  • Nick Gilman, MD, FAAP

    Dr. Nick Gilman grew up in Denver, CO. He graduated from Reed College in Portland, OR with a degree in English Literature and soon after became an EMT at Children’s Hospital ER in Denver.  Then, while completing a year of service through Americorps VISTA in Baton Rouge, LA where he worked to enhance community services for individuals with HIV/AIDS, he met his future wife and decided to pursue a medical degree. He attended medical school at George Washington University in Washington, DC and returned to University of Colorado for his pediatric residency. After residency, he fulfilled a National Health Service commitment in Yakima, WA. Following nearly seven years there, Nick returned home to Denver where he lives with his wife (Carrie), daughter (Opal “who loves books”) and a very naughty cat named Stevie Johnston.  He loves spending time in the mountains and working with families through the joys and adventures of childhood.

  • Brienna Miller, MD

    Dr. Brienna Miller grew up in Indiana. She graduated from Purdue University with a degree in business and went on to obtain an MBA at Roosevelt University in Chicago. Due to her desire for a more meaningful career, she decided to switch gears and attended Harvard University to take prerequisite science classes. Once completed, she went on to Medical School at the University of Queensland/Ochsner Clinical School. Her first two years were spent in Brisbane, Australia followed by two years in New Orleans for her clinical rotations. She completed her residency at the University of Massachusetts/Baystate Medical Center. After moving around frequently for her education, she was thrilled to move to Colorado and settle down close to family. In her free time, she enjoys traveling, camping with friends, exploring new restaurants, attending concerts, spoiling her niece and nephew, and taking her golden retriever puppy everywhere with her. She is exited to help your children become the happiest and healthiest versions of themselves!

Our Locations

Hours of Operation


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8:00 am-12:00 pm