Characterization of a ring chromosome 21 by FISH-technique

Clinical Genetics
R A ConteR S Verma

Abstract

Ring chromosomes 21 that contain two copies of the Down syndrome critical region (DCR1), thereby contributing to trisomic dosage, have not been fully characterized by routine cytogenetic methods in the past. We therefore employed the fluorescence in situ hybridization (FISH) technique, using a battery of chromosome 21 probes and conclude that the ring resulted from a centromere to centromere and long arm to long arm fusion that contains alpha-satellite DNA and two copies of the D21S65 locus, but lacks beta-satellite DNA and telomeric DNA. Consequently, we suggest that the origin of the ring may be due to the misdivision of the centromere following the duplication of the long arm, forming a monocentric isochromosome followed by breakage in a region distal to the D21S65 locus and proximal to the telomeric sequences followed by reunion of the broken ends resulting in a monocentric ring. Different ring configurations or fragments were not detected, suggesting that the ring chromosome was highly stable. Apparently, the presence of two copies of Down syndrome loci within the ring chromosome, along with one copy on the normal homologue, caused the clinical consequences of Down syndrome.

References

Mar 1, 1977·Clinical Genetics·R S VermaH A Lubs
Jan 1, 1992·American Journal of Medical Genetics·T C Falik-BorensteinJ R Korenberg
Dec 1, 1992·Genomics·S E Antonarakis
Mar 1, 1989·Proceedings of the National Academy of Sciences of the United States of America·C WongS E Antonarakis
Dec 1, 1985·Clinical Genetics·J L HuretV Kanoui
Jan 1, 1980·Human Genetics·A IeshimaY Kuroki
May 24, 1994·Proceedings of the National Academy of Sciences of the United States of America·J R KorenbergC Disteche
Dec 1, 1993·Genomics·J M DelabarD Patterson

❮ Previous
Next ❯

Citations

Sep 17, 2004·American Journal of Medical Genetics. Part a·Alan F RopeHoward M Saal

❮ Previous
Next ❯

Related Concepts

Trending Feeds

COVID-19

Coronaviruses encompass a large family of viruses that cause the common cold as well as more serious diseases, such as the ongoing outbreak of coronavirus disease 2019 (COVID-19; formally known as 2019-nCoV). Coronaviruses can spread from animals to humans; symptoms include fever, cough, shortness of breath, and breathing difficulties; in more severe cases, infection can lead to death. This feed covers recent research on COVID-19.

Blastomycosis

Blastomycosis fungal infections spread through inhaling Blastomyces dermatitidis spores. Discover the latest research on blastomycosis fungal infections here.

Nuclear Pore Complex in ALS/FTD

Alterations in nucleocytoplasmic transport, controlled by the nuclear pore complex, may be involved in the pathomechanism underlying multiple neurodegenerative diseases including Amyotrophic Lateral Sclerosis and Frontotemporal Dementia. Here is the latest research on the nuclear pore complex in ALS and FTD.

Applications of Molecular Barcoding

The concept of molecular barcoding is that each original DNA or RNA molecule is attached to a unique sequence barcode. Sequence reads having different barcodes represent different original molecules, while sequence reads having the same barcode are results of PCR duplication from one original molecule. Discover the latest research on molecular barcoding here.

Chronic Fatigue Syndrome

Chronic fatigue syndrome is a disease characterized by unexplained disabling fatigue; the pathology of which is incompletely understood. Discover the latest research on chronic fatigue syndrome here.

Evolution of Pluripotency

Pluripotency refers to the ability of a cell to develop into three primary germ cell layers of the embryo. This feed focuses on the mechanisms that underlie the evolution of pluripotency. Here is the latest research.

Position Effect Variegation

Position Effect Variagation occurs when a gene is inactivated due to its positioning near heterochromatic regions within a chromosome. Discover the latest research on Position Effect Variagation here.

STING Receptor Agonists

Stimulator of IFN genes (STING) are a group of transmembrane proteins that are involved in the induction of type I interferon that is important in the innate immune response. The stimulation of STING has been an active area of research in the treatment of cancer and infectious diseases. Here is the latest research on STING receptor agonists.

Microbicide

Microbicides are products that can be applied to vaginal or rectal mucosal surfaces with the goal of preventing, or at least significantly reducing, the transmission of sexually transmitted infections. Here is the latest research on microbicides.