title: A neocentric isochromosome Yp present as additional small supernumerary marker chromosome--evidence against U-type exchange mechanism?
abstract: Here we report the first case of an inverted duplicated neocentric small supernumerary marker chromosome present in a karyotype 47,XX,+mar(Y). As expected a partial disomy of Ypter to Yp11.2 did not lead to any major malformations. However, the formation of an inverted duplicated chromosome from a Y chromosome is not possible by a U-type exchange, as has been suggested for such kind of neocentric marker chromosomes. Thus, some evidence is here provided that this concept might not always be true.
authors.affiliation: Institute of Human Genetics, Foundation for Research in Genetics and Endocrinology (FRIGE), Ahmedabad, India.
authors.forename: F
authors.initials: F
authors.lastname: Sheth
authors.forename: E
authors.initials: E
authors.lastname: Ewers
authors.forename: N
authors.initials: N
authors.lastname: Kosyakova
authors.forename: A
authors.initials: A
authors.lastname: Weise
authors.forename: J
authors.initials: J
authors.lastname: Sheth
authors.forename: S
authors.initials: S
authors.lastname: Patil
authors.forename: M
authors.initials: M
authors.lastname: Ziegler
authors.forename: T
authors.initials: T
authors.lastname: Liehr
mesh_terms: D002869:Chromosome Aberrations; D041322:Chromosomes, Human, Y; D005260:Female; D005819:Genetic Markers; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D018404:Isochromosomes; D007621:Karyotyping; D008297:Male
chemical_list: D005819:Genetic Markers