title: Small supernumerary marker chromosomes 1 with a normal phenotype.
abstract: Small supernumerary marker chromosomes (sSMCs) are a major problem in prenatal cytogenetic diagnostics. Over two-thirds of cases carrying an sSMC derived from chromosome 1 are associated with clinical abnormalities. We report 3 further cases of such sSMCs that did not show any clinical abnormalities. All 3 sSMCs studied were detected prenatally and characterized comprehensively for their genetic content by molecular cytogenetics using subcentromere-specific multicolor fluorescence in situ hybridization, and for a possibly associated uniparental disomy. After exclusion of additional euchromatin due to the presence of sSMCs and a uniparental disomy, parents opted for continuation of the pregnancies and healthy children were born in all 3 cases. It is important to quickly and clearly characterize prenatal sSMCs. Also, all available sSMC cases need to be collected on a homepage such as the Jena Institute of Human Genetics and Anthropology sSMC homepage (http://www.med.uni-jena.de/fish/sSMC/00START.htm).
authors.affiliation: Jena University Hospital, Institute of Human Genetics and Anthropology, Germany. i8lith@mti.uni-jena.de
authors.forename: Thomas
authors.initials: T
authors.lastname: Liehr
authors.forename: Rolf-Dieter
authors.initials: RD
authors.lastname: Wegner
authors.forename: Markus
authors.initials: M
authors.lastname: Stumm
authors.forename: Thomas
authors.initials: T
authors.lastname: Martin
authors.forename: Gabriele
authors.initials: G
authors.lastname: Gillessen-Kaesbach
authors.forename: Nadezda
authors.initials: N
authors.lastname: Kosyakova
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Ewers
authors.forename: Ahmed Basheer
authors.initials: AB
authors.lastname: Hamid
authors.forename: Ferdinand
authors.initials: F
authors.lastname: von Eggeling
authors.forename: Julia
authors.initials: J
authors.lastname: Hentschel
authors.forename: Monika
authors.initials: M
authors.lastname: Ziegler
authors.forename: Anja
authors.initials: A
authors.lastname: Weise
mesh_terms: D002869:Chromosome Aberrations; D002878:Chromosomes, Human, Pair 1; D055028:Comparative Genomic Hybridization; D005819:Genetic Markers; D006801:Humans; D007231:Infant, Newborn; D010641:Phenotype; D011296:Prenatal Diagnosis
chemical_list: D005819:Genetic Markers