<abstract xml:lang="en" xmlns="http://www.w3.org/1999/xhtml"><p>We describe a trisomy 21 with a small supernumerary marker chromosome (sSMC) derived from chromosomes 13/21 and 18 in which the karyotype was 48, XY, +der(13 or 21)t(13 or 21;18)(13 or 21pter→13q11 or 21q11.1::18p 11.21→18pter),+21. Of the 35 case reports in the literature for a karyotype 48, XN, +21,+mar, in only 12 was the origin of the sSMC determined by fluorescence <italic>in situ</italic> hybridization (FISH), and only one was a der(13 or 21) and none were derived from two chromosomes. The influence of the partial trisomy 18p on the clinical outcome was hard to determine, however, there are reports on clinically healthy subjects for partial trisomy 18p.</p></abstract>

We describe a trisomy 21 with a small supernumerary marker chromosome (sSMC) derived from chromosomes 13/21 and 18 in which the karyotype was 48, XY, +der(13 or 21)t(13 or 21;18)(13 or 21pter→13q11 or 21q11.1::18p 11.21→18pter),+21. Of the 35 case reports in the literature for a karyotype 48, XN, +21,+mar, in only 12 was the origin of the sSMC determined by fluorescence in situ hybridization (FISH), and only one was a der(13 or 21) and none were derived from two chromosomes. The influence of the partial trisomy 18p on the clinical outcome was hard to determine, however, there are reports on clinically healthy subjects for partial trisomy 18p.

Trisomy 21 with a Small Supernumerary Marker Chromosome Derived from Chromosomes 13/21 and 18

Department of Medical Genetics, Institute of Mental Health, Belgrade, Serbia

University Children's Hospital, Belgrade, Serbia

Institute of Human Genetics and Anthropology, Jena University Hospital, Jena, Germany

Balkan Journal of Medical Genetics

We describe a trisomy 21 with a small supernumerary marker chromosome (sSMC) derived from chromosomes 13/21 and 18 in which the karyotype was 48, XY, +der(13...

Trisomy 21 with a Small Supernumerary Marker Chromosome Derived from Chromosomes 13/21 and 18

Published Online: Aug 25, 2010

Page range: 55 - 58

DOI: https://doi.org/10.2478/v10034-010-0020-x

Keywords
small supernumerary marker chromosome (sSMC), Partial trisomy 18p, Down syndrome

This content is open access.

Trisomy 21 with a Small Supernumerary Marker Chromosome Derived from Chromosomes 13/21 and 18

Published Online: Aug 25, 2010

Page range: 55 - 58

DOI: https://doi.org/10.2478/v10034-010-0020-x

Keywordssmall supernumerary marker chromosome (sSMC), Partial trisomy 18p, Down syndrome

This content is open access.

Keywords
small supernumerary marker chromosome (sSMC), Partial trisomy 18p, Down syndrome