We report an uncle and niece with duplication and deletion, respectively, of segment 7p15 → 7p21 originating from a balanced, intrachromosomal insertion in their mothers. The proposita had prenatal and postnatal growth deficiency, retarded psychomotor development, microcephaly, wide cranial sutures, ocular hypertelorism, small palpebral fissures, apparently low‐set and malformed ears, cleft palate, congenital heart defect, hypoplasia of the distal phalanx of first fingers, rocker‐bottom feet, persistent cloaca, and imperforate anus. She died at three months. Her maternal uncle has duplication of this segment and is alive at 32 years. He has severe mental deficiency, but normal growth; communicating hydrocephalus was diagnosed at three months.