Our Staff

Dr. Jeffrey Mantia, M.D., FAAP
Board certified pediatrician

A native of St. Louis, Missouri, and longtime Kalamazoo resident, Dr. Mantia received his undergraduate degree from Kalamazoo College and his medical degree from Michigan State University.  He completed his pediatric residency training at DeVos Children's Hospital in Grand Rapids.  After working in hospital owned offices in Knoxville, Tennessee and southeast Grand Rapids, Dr. Mantia founded Grandville Pediatrics in 2001. 

While he enjoys all aspects of pediatric care, he has particular interests in sports medicine, nutrition, education, vaccine advocacy and international adoption.  He is married and has 2 sons.  His outside interests include travel, guitar, bicycling, watching movies and attending musical performances and sporting events.


Abigail Lamar MSN, RN, CPNP
Board Certified Pediatric Nurse Practitioner

Abigail ("Abi")  has lived in Holland, Michigan her whole life. She attended Grand Valley State University for both her BSN and MSN. She worked for 4 years as an RN at Helen DeVos Children’s Hospital, including 1 year with the Pediatric Nephrology team. She has been working as a Pediatric Nurse Practitioner since 2008 and originally worked for a primary care pediatric group in Holland as well as for the Pediatric Hospitalist group in Holland. Most recently, Abi spent 5 years working in the Pediatric Emergency Department at Helen DeVos Children’s Hospital before joining Grandville Pediatrics in 2017.   Abi is married and has 3 daughters, including a set of identical twins. In addition to spending time with her family Abi enjoys spending time outdoors, boating, fitness, sports, traveling and gardening. Abi looks forward to meeting with you and talking about your child’s healthcare needs.


Emily Rusticus, MSN, RN, CFNP
Board Certified Family Nurse Practitioner

Emily received her nursing degree from Trinity College in Palos Heights, IL. She worked at Children's Memorial Hospital in Chicago for several years, and locally at Helen Devos Children's Hospital after returning to the Grand Rapids area. She received her FNP degree from St. Louis University and worked locally in a Family Practice office prior to joining Grandville Pediatrics in 2017. Growing up as an athlete, Emily is particularly interested in pediatric sports medicine, but also enjoys nutrition and weight management, female adolescent concerns, and infant care. She lives in Grand Rapids with her husband, daughter and Border Collie/Australian Shepherd mix. She enjoys anything sports related (Go Green!), hiking, running and Netflix.


Jenna Sargent, MSN, RN, CPNP
Board Certified Pediatric Nurse Practitioner

Jenna was born and raised in Grand Rapids and received her undergraduate degree in nursing from the University of Michigan. She worked as a registered nurse in the neonatal ICU at Helen DeVos Children’s Hospital for 1 ½ years and then transferred to the Pediatric Perioperative Unit and worked there for 3 ½ years. She received her master’s in nursing and completed the Pediatric Nurse Practitioner program at Wayne State University. In her spare time, she loves spending time with her family and her Maltese-Yorkie dog. She is a big Michigan fan and enjoys going to U of M football games in the fall. She also enjoys running, being outdoors, reading, and traveling.