title: [Tetrasomy 9p].
abstract: A newborn male with multiple malformations and an extrachromosome is presented. The cytogenetic study of peripheral blood lymphocytes revealed tetrasomy 9p: 47,XY, + t(9;9)(pter----q13::p11----pter). The C-banding pattern provided evidence for maternal origin of the extrachromosome. Tetrasomy for the short arm of chromosome 9 is a very rare condition; reports about only ten further patients have been found in the literature. The phenotypic expression resembles trisomy 9p, but tetrasomy 9p has more severe additional malformations.
authors.forename: W
authors.initials: W
authors.lastname: Foerster
authors.forename: M
authors.initials: M
authors.lastname: Koch
authors.forename: S
authors.initials: S
authors.lastname: Hansen
mesh_terms: D000015:Abnormalities, Multiple / Q000235:genetics*; D001132:Arm / Q000002:abnormalities; D001921:Brain / Q000002:abnormalities; D002869:Chromosome Aberrations / Q000235:genetics*; D002871:Chromosome Banding; D025063:Chromosome Disorders; D002906:Chromosomes, Human, 6-12 and X; D002971:Cleft Lip / Q000235:genetics; D002972:Cleft Palate / Q000235:genetics; D003456:Cryptorchidism / Q000235:genetics; D006330:Heart Defects, Congenital / Q000235:genetics; D006801:Humans; D007231:Infant, Newborn; D007866:Leg / Q000002:abnormalities; D008297:Male
vernacular_title: Tetrasomie 9p.