title: Monosomy 18p and pure trisomy 18p in a family with translocation (7;18).
abstract: A three generation pedigree is described in which there are two carriers of translocation t(7;18). Two members of the family have trisomy 18p and a stillborn child had monosomy 18p and holoprosencephaly. Another stillborn child probably had holoprosencephaly; the karyotype was not analysed. Based on this observation, the occasional occurrence of holoprosencephaly in monosomy 18p (10% of previously reported cases) may not be the result of the expression of a recessive mutant gene in the hemizygous state, as assumed up to now.
mesh_terms: D000015:Abnormalities, Multiple / Q000235:genetics; D000328:Adult; D002675:Child, Preschool; D002869:Chromosome Aberrations; D002902:Chromosomes, Human, 16-18; D002906:Chromosomes, Human, 6-12 and X; D005145:Face / Q000002:abnormalities; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D014178:Translocation, Genetic; D014314:Trisomy