Identification of an unusual marker chromosome by spectral karyotyping

Abstract

We ascertained a newborn girl with multiple congenital anomalies including severe hypotonia, cardiovascular defects, hearing loss, central nervous system anomalies, and facial anomalies. The infant died at 12 days. Cytogenetic analysis showed a de novo supernumerary marker chromosome. Fluorescence in situ hybridization (FISH) with a combination of chromosome specific alpha-satellite probes and an all-human centromere probe failed to show hybridization to the marker, indicating that the marker chromosome lacked detectable alpha satellite sequences. Spectral karyotyping (SKY) was performed and showed that the marker was chromosome 15 in origin. This was confirmed by FISH with a 15q specific subtelomerie probe, which showed hybridization to both ends of the marker chromosome. Based on FISH information and G-banding pattern, the marker was determined to be an inverted duplication of 15q25-qter, leading to partial tetrasomy for chromosome 15. Although the marker chromosome lacked detectable centromeric alpha-satellite sequences, it seemed to have a functional centromere as it is mitotically stable. This observation is consistent with previous studies on acentric marker chromosomes, which suggested that the DNA sequence at the breakpoint could function similarly to alpha-satellite sequences once activated through marker formation.

Establishment of novel human dedifferentiated chondrosarcoma cell line with osteoblastic differentiation

“…The Standard trypsin-Giemsa banding technique [51] was performed for cells obtained after 20 passages, and additional slides were made for spectral karyotyping analysis, according to the manufacturer's protocol (Applied Spectral Imaging, Migdal Ha'Emek, Israel) [25,50,58]. Clonal chromosomal abnormalities were described according to the International System for Human Cytogenetics (ISCN 1995) [42].…”

Tetrasomy 15q26: a distinct syndrome or Shprintzen-Goldberg syndrome phenocopy?

“…There have been at least 13 previously reported cases of tetrasomy 15q in the form of a marker chromosome. 10,11,15,[20][21][22][23][24][25][26][27][28][29] However, in only 10 of the 13 are specific clinical data available ( Table 1) with 9 of the 10 reported as mosaic tetrasomy 15q. Nonetheless, the craniofacial gestalt observed in all our cases is also present in eight of eight cases tetrasomic for 15q25 where clinical images are available ( Table 1).…”

Sensitivity of Multiple Color Spectral Karyotyping in Detecting Small Interchromosomal Rearrangements

“…Many complex chromosom e rearrangem ents in leukemia and cancer cells have been characterized with this recently developed technology (Coleman et al, 1997;Veldman et al, 1997;Allen et al, 1998;Rao et al, 1998;Sawyer et al, 1998;Zattara-Cannon i et al, 1998;Fleischm an et al, 1999;Padilla-Nash et al, 1999;Rogatta et al, 1999;Rowley et al, 1999;Trakhtenbrot et al, 1999). SKY has also refined the cytogenetic diagnosis for some constitutional chromosomal abnormalities, thereby contributing to the understanding of genotype-phenotype correlations in dysmorphic syndromes Haddad et al, 1998;Huang et al, 1998;Phelan et al, 1998;Reddy et al, 1999). On the basis of the resolution level of G-binding and the information obtained from the FISH studies with subtelomeric probes, we estimated that the minimum alteration that SKY can detect is in the range of 1,000 to 2,000 kbp in size with the currently available probes.…”

“…The recently developed technology of spectral karyotyping (SKY) allows a simultaneous visualization of all human chromosom es by a single hybridization of 24 differentially labeled chromosom e painting probes and provides a very useful tool for the characterization of the complex chromosome rearrangements in cancer cells Schröck et al, 1996;Coleman et al, 1997;Veldman et al, 1997;Allen et al, 1998;Rao et al, 1998;Sawyer et al, 1998;Zattara-Cannon i et al, 1998;Fleischman et al, 1999;Padilla-Nash et al, 1999;Rogatta et al, 1999;Rowley et al, 1999;Trakhtenbrot et al, 1999) and in de novo constitutional structural abnormalities Haddad et al, 1998;Huang et al, 1998;Phelan et al, 1998;Reddy et al, 1999).…”