Meet Our Family Doctors in Mount Pleasant, SC

John A. Knepper, DO

Dr. Knepper attended medical school at the Osteopathic Medical College of Philadelphia. In 1988 he moved to Mount Pleasant, SC to complete his Internship and Residency Training in Family Practice at the US Naval Hospital Charleston. From 1991 to 1994, Dr. Knepper served with the US Navy as a Family Practice physician in Okinawa. In March 2000, he established Sewee Family Medicine.

Dr. Knepper is board certified in Family Practice. His is a member of the American Academy of Family Physicians and the American Board of Family Practice.

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Elizabeth T Whirrett, MD

Dr. Whirrett attended medical school at FUHS/The Chicago Medical School. She did her residency in Columbia SC at Richland Memorial Hospital. She moved to Charleston in 2004 and has been practicing in West Ashley for 8 years.

Dr. Whirrett is board certified in Family Medicine.

Elizabeth T Whirrett

Justine Dela Rosa DeCastro, MD

Dr. DeCastro is a Charleston native who graduated from Bishop England High School and attended the University of SC for her undergraduate studies and medical school. She served as a physician and active duty Captain in the US Air Force while stationed at Barksdale AFB, LA. After completing her military commitment, she returned to Charleston for her residency in Family Medicine at Trident / MUSC. Prior to joining Sewee Family Medicine, Dr. DeCastro has had experience in primary care, urgent care, long-term care and rehab as well as nursing home care.

Dr. DeCastro is board certified in Family Medicine and has specific interests in acute care, preventive medicine & chronic disease management. Outside of the clinic, she enjoys staying active and exercising, volunteering at her children's school and spending time with her family. Her husband, Dr. Alec DeCastro, is currently the Trident / MUSC Family Medicine residency program director.

Dr. DeCastro enjoys being active in the community and volunteers as an attending preceptor for MUSC medical students at the local CARES free medical clinic. She is also an active member of the Junior League of Charleston, an organization of women volunteers who improve the community through fundraising and volunteerism. 

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