Mosaic variegated aneuploidy, being a rare recessive condition characterized by growth retardation, microcephaly, childhood cancer and a constitutional mosaicism for chromosomal gains and losses is attributed to truncating and missense mutations in the BUB1B gene, which encodes for the mitotic spindle checkpoint protein BUBR1 [84]. The gene discussed is BUB1B; the disease is childhood malignant neoplasm.