Dwarfism may be familial (inherited as an autosomal recessive, usually against a background of consanguinity) or it may be sporadic; when it arises from isolated deficiency of HGH, reproductive function is unimpaired. Or there may be specific or generalized insensitivity of the tissues to apparently normal HGH; the latter appears to be the situation with the pygmy tribes found in Africa and other parts of the world.