The determined karyotype was 47,XXY,+mar (figure 1A), which was compatible with apparently Klinefelter syndrome male with an additional marker chromosome
. To investigate further, karyotype was performed for both parents on PHA stimulated lymphocyte cultures; both were normal (figures 1B and 1C).
In 3 cases, ICP identified the origin of a marker chromosome
(cases 53, 54, 55; Figure 6, A through D).
Karyotype showed marker chromosome
(Figure 1(c)) and CMA partial trisomy of 11q and 22q characteristic of Emanuel syndrome (ES) .
A small supernumerary marker chromosome
(sSMC) is defined as an abnormal chromosome that is generally equal in size to or smaller than chromosome 20, and its derivation cannot be detected by conventional chromosomal banding techniques .
Singh, "Mixed phenotype acute leukemia of t/myeloid type with rare multiple cytogenetic abnormality of chromosome 8, 9, 11, 12, 16 and marker chromosome
and dual blast population: a rare case," Medico Research Chronicles, vol.
It is deemed that the single chromosome was included when the following structural aberration existed: chromosome/chromatide break, acentric fragment, ring fragment, minute, acentric ring, ring chromosome, marker chromosome
. Two chromosomes are deemed included when the following structural aberration existed: dicentric chromosome and translocation.
If a marker chromosome
is detected, microarray will identify it.
diversicolor supertexta karyotype can serve as a marker chromosome
pair, as they are subtelocentric (or telocentric in some metaphases) chromosomes and quite different from all chromosome pairs for H.
Bernardini et al., "Interstitial 4q deletion associated with a mosaic complementary supernumerary marker chromosome
in prenatal diagnosis," Prenatal Diagnosis, vol.
There were no clonal rearrangements except for the constant presence of a large marker chromosome
(denoted as mar1) that appeared as 1, 2, or 4 copies (Figure, h).
Molecular characterization of the marker chromosome
associated with cat eye syndrome.
Beside this unprecedented high detection rate of common aneuploidies, some studies highlighted the usefulness of this screening strategy to detect a much broader range of chromosomal aberrations, including triploidy, small supernumerary marker chromosomes
and rare numerical and/or structural chromosomal abnormalities (5).