The second child of the unhappy marriage of Orford Umbridge and his Muggle wife, Ellen. The boy turned out to be a squib, and when the parents split up, Ellen took their son with her back to the Muggle world. Dolores never saw her brother again. Umbridge denied even the existence of her Muggle and squib family members and instead claimed to be pure blood (Pm).
Species / Race Squib
First Introduced Pm: Pottermore