"What is Down syndrome?" is the first book from the the Ugo and Sim Sim book series, which aim to foster representation of black children and those with special needs.

Ugo and Sim Sim are stories about the every day life of a brother and sister living in Lagos, Nigeria. Ugo is a handsome and friendly boy who is curious about everything. Sim Sim is his cute and outgoing sister with Down syndrome. Together, they take on daily challenges (and sometimes each other) as they learn about life. Topics range from understanding what Down syndrome is to bad hair days.