During the last decades, Cytogenetic and Genome Research has been the leading forum for original reports and reviews in human, animal, insect, and plant cytogenetics, including clinical, molecular, and comparative cytogenetics.

Cytogenetics is the study of chromosomal structure, location and function in cells. It includes the study of chromosome number and appearance (karyotyping), the physical location of genes on chromosomes, and chromosomal behaviour in processes such as cell division. It is a field of study that deals with chromosomes and related abnormalities. Chromosome analysis is also known as karyotyping and involves the pairing of homologous chromosomes.

Uses

• genome research, including chromosome structure and function

• genome evolution

• human disease pathogenesis, cancer genomics, gene regulation and expression

• epigenetics

• diagnosis of oncologic and hematologic disorders

• diagnosis and classification of disease

• planning treatment regimens and monitoring the status of disease

The cytogenetic studies the number and morphology of chromosomes by using chromosome banding techniques (classical cytogenetics) or hybridization fluorescently labeled probes (molecular cytogenetics). The number and morphology of chromosomes in a cell of a particular species are always constant, in most cells of the body (with the exception of reproductive cells and others such as the liver). This is a characteristic of each specie, in humans such as the number of chromosomes is 46.

Abnormalities in chromosomes cause several genetic disorders leading to developmental delay, congenital malformations, mental retardation, and infertility. Cytogenetic analysis is very crucial in the diagnosis of oncologic and hematologic disorders.

Cytogenetic analysis plays a critical role in the diagnosis, classification, prognosis, and management of acute myeloid leukemia (AML). It has become an essential technique that helps doctors identify leukemia and provide treatment guidance. Cytogenetic testing is usually performed on the bone marrow of AML patients and helps in characterizing the aggressiveness of leukemia. Moreover, it assists in determining treatment response and overall prognosis.

In addition to providing associations between chromosomal abnormalities and disease, cytogenetic approaches have also allowed researchers to map genes to particular chromosomes. For example, in 1968, Roger Donahue used new methods to study metaphase chromosomes in his own blood cells, and he noted that one of his copies of chromosome 1 had a region near the centromere that was loosely structured and uncoiled. Using his extended family pedigree and conducting biochemical tests to determine blood group markers, Donahue employed cytogenetic techniques to map the Duffy blood group locus to chromosome 1.

Chromosome analyses require cell cultures and involves the harvesting of chromosomes, chromosome banding, microscopic analysis and the production of karyotypes. Advances now focus on molecular cytogenetics including automated systems for counting the results of standard FISH preparations and techniques for virtual karyotyping, such as comparative genomic hybridization arrays, CGH and Single nucleotide polymorphism arrays.

Molecular Cytogenetic Testing (FISH)

It is also called fluorescence in-situ hybridization (FISH). FISH testing involves the determination of the presence, absence, position, and copy number of DNA segments with the help of fluorescence microscopy.