Marjolein Buis was born in Nijmegen, the Netherlands. At the age of 14 she started to experience problems when walking. It turned out that she has a connective tissue disorder, the Ehlers–Danlos syndrome, which affects the stability of the joints. She would never be able to play able bodied sports again. At the age of 17, Marjolein discovered wheelchair tennis. In 2010 she graduated in Social Work and became a full-time tennis player. She qualified for the Paralympic Games in London 2012 and reached the quarter final in singles and won gold in doubles with her partner Esther Vergeer. Marjolein is still a full-time player and her goal is to win a medal in singles at the Paralympic Games in Rio 2016. In her spare time she studies Psychology.