Nilo-Saharan languages
Linguist Roger Blench has suggested that the Nilo-Saharan languages and the Niger–Congo languages may be branches of the same macro–language family. Earlier proposals along this line were made by linguist Edgar Gregersen in 1972. These proposals have not reached a linguistic consensus, however, and this connection presupposes that all of the Nilo-Saharan languages are actually related in a single family, which has not been definitively established.