Small supernumerary marker chromosomes 1 with a normal phenotype.
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).
Liehr
Thomas
T
Jena University Hospital, Institute of Human Genetics and Anthropology, Germany. i8lith@mti.uni-jena.de
Wegner
Rolf-Dieter
RD
Stumm
Markus
M
Martin
Thomas
T
Gillessen-Kaesbach
Gabriele
G
Kosyakova
Nadezda
N
Ewers
Elisabeth
E
Hamid
Ahmed Basheer
AB
von Eggeling
Ferdinand
F
Hentschel
Julia
J
Ziegler
Monika
M
Weise
Anja
A
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
D005819:Genetic Markers