The article below--"The Medical Van Leer Family of Pennsylvnia and New Jersey"--is  from Transactions & Studies of the College of Physicians of Philadelphia, 4 Ser., Vol. 38, No. 1, July 1970.  It gives a short biography of Dr. Bernardhus Van Leer, who practiced in Chester County, PA. and his son Benjamin Van Leer of Gloucester County, NJ.

The "Vanleer Papers" stored at the Chester County Historical Society also note that his son Branson was a medical doctor and surgeon during the American Revolution.