A 5-year-old male with multiple malformations (dwarfism, microcephalia with brachycephalic shape of skull, mongoloid lid axis, epicanthus, convergent strabismus, flat root of the nose, micrognathia, missing uvula, deformed low-set ears, hypoplastic genitals, and general hypotonia), severe mental retardation, and cerebral paroxysms caused by a partial monosomy (1)(q42 leads to qter) is described. This case is compared with other cases with a partial monosomy or ring-1 chromosomes.