Chromosome testing can be accomplished using several techniques, all of which can identify chromosomal abnormalities. Karyotyping (a technique that involves staining, organization, and visualization of chromosomes) is used to identify aneuploidy and major structural changes. Karyotyping is not sensitive in identifying small abnormalities and is a labor-intensive process. Chromosomal microarray analysis is a comparative technique that utilizes fluorescence to identify and quantify specific genetic sequences and is much more sensitive in identifying copy number variants, such as microdeletions or microduplications. However, chromosomal microarray analysis is not useful in identifying certain variations such as balanced translocations. Fluorescence in situ hybridization utilizes fluorescent probes to identify and locate specific genes on chromosomes. Compared with karyotyping, FISH is much more sensitive and specific in determining several abnormalities (except for point mutations) but is limited by the currently available gene probes.
Last updated: Aug 9, 2022
Numerical chromosomal aberrations:
Structural chromosomal aberrations:
Karyotyping, also known as chromosomal analysis, is a common method of producing an image of an individual’s chromosomes Chromosomes In a prokaryotic cell or in the nucleus of a eukaryotic cell, a structure consisting of or containing DNA which carries the genetic information essential to the cell. DNA Types and Structure to detect:
Review of the stages of
mitosis
Mitosis
A type of cell nucleus division by means of which the two daughter nuclei normally receive identical complements of the number of chromosomes of the somatic cells of the species.
Cell Cycle:
prophase
Prophase
The first phase of cell nucleus division, in which the chromosomes become visible, the cell nucleus starts to lose its identity, the spindle apparatus appears, and the centrioles migrate toward opposite poles.
Cell Cycle,
prometaphase
Prometaphase
The phase of cell nucleus division following prophase, when the breakdown of the nuclear envelope occurs and the mitotic spindle apparatus enters the nuclear region and attaches to the kinetochores.
Cell Cycle,
metaphase
Metaphase
The phase of cell nucleus division following prometaphase, in which the chromosomes line up across the equatorial plane of the spindle apparatus prior to separation.
Cell Cycle,
anaphase
Anaphase
The phase of cell nucleus division following metaphase, in which the chromatids separate and migrate to opposite poles of the spindle.
Cell Cycle, and
telophase
Telophase
The final phase of cell nucleus division following anaphase, in which two daughter nuclei are formed, the cytoplasm completes division, and the chromosomes lose their distinctness and are transformed into chromatin threads.
Cell Cycle:
During karyotyping, the
cell cycle
Cell cycle
The phases of the cell cycle include interphase (G1, S, and G2) and mitosis (prophase, metaphase, anaphase, and telophase). The cell’s progression through these phases is punctuated by checkpoints regulated by cyclins, cyclin-dependent kinases, tumor suppressors, and their antagonists.
Cell Cycle is halted in
metaphase
Metaphase
The phase of cell nucleus division following prometaphase, in which the chromosomes line up across the equatorial plane of the spindle apparatus prior to separation.
Cell Cycle, usually by adding an agent like
colchicine
Colchicine
A major alkaloid from colchicum autumnale l. And found also in other colchicum species. Its primary therapeutic use is in the treatment of gout.
Gout Drugs (inhibits microtubule polymerization to halt
mitosis
Mitosis
A type of cell nucleus division by means of which the two daughter nuclei normally receive identical complements of the number of chromosomes of the somatic cells of the species.
Cell Cycle).
Karyotyping is useful for identifying and diagnosing:
Karyotype Karyotype The full set of chromosomes presented as a systematized array of metaphase chromosomes from a photomicrograph of a single cell nucleus arranged in pairs in descending order of size and according to the position of the centromere. Congenital Malformations of the Female Reproductive System of a normal human male: A karyotype Karyotype The full set of chromosomes presented as a systematized array of metaphase chromosomes from a photomicrograph of a single cell nucleus arranged in pairs in descending order of size and according to the position of the centromere. Congenital Malformations of the Female Reproductive System is a laboratory technique whereby an individual’s chromosomes Chromosomes In a prokaryotic cell or in the nucleus of a eukaryotic cell, a structure consisting of or containing DNA which carries the genetic information essential to the cell. DNA Types and Structure are paired and photographed.
Image: “NHGRI human male karyotype Karyotype The full set of chromosomes presented as a systematized array of metaphase chromosomes from a photomicrograph of a single cell nucleus arranged in pairs in descending order of size and according to the position of the centromere. Congenital Malformations of the Female Reproductive System” by National Human Genome Genome The complete genetic complement contained in the DNA of a set of chromosomes in a human. The length of the human genome is about 3 billion base pairs. Basic Terms of Genetics Research Research Critical and exhaustive investigation or experimentation, having for its aim the discovery of new facts and their correct interpretation, the revision of accepted conclusions, theories, or laws in the light of newly discovered facts, or the practical application of such new or revised conclusions, theories, or laws. Conflict of Interest Institute. License: Public DomainKaryotype Karyotype The full set of chromosomes presented as a systematized array of metaphase chromosomes from a photomicrograph of a single cell nucleus arranged in pairs in descending order of size and according to the position of the centromere. Congenital Malformations of the Female Reproductive System of trisomy 21 Trisomy 21 Down syndrome, or trisomy 21, is the most common chromosomal aberration and the most frequent genetic cause of developmental delay. Both boys and girls are affected and have characteristic craniofacial and musculoskeletal features, as well as multiple medical anomalies involving the cardiac, gastrointestinal, ocular, and auditory systems. Down syndrome (Trisomy 21) ( Down syndrome Down syndrome Down syndrome, or trisomy 21, is the most common chromosomal aberration and the most frequent genetic cause of developmental delay. Both boys and girls are affected and have characteristic craniofacial and musculoskeletal features, as well as multiple medical anomalies involving the cardiac, gastrointestinal, ocular, and auditory systems. Down syndrome (Trisomy 21)): In an individual with Down syndrome Down syndrome Down syndrome, or trisomy 21, is the most common chromosomal aberration and the most frequent genetic cause of developmental delay. Both boys and girls are affected and have characteristic craniofacial and musculoskeletal features, as well as multiple medical anomalies involving the cardiac, gastrointestinal, ocular, and auditory systems. Down syndrome (Trisomy 21), 3 copies of chromosome Chromosome In a prokaryotic cell or in the nucleus of a eukaryotic cell, a structure consisting of or containing DNA which carries the genetic information essential to the cell. Basic Terms of Genetics 21 are usually visible (red box and arrow).
Image: “21 trisomy Trisomy The possession of a third chromosome of any one type in an otherwise diploid cell. Types of Mutations – Down syndrome Down syndrome Down syndrome, or trisomy 21, is the most common chromosomal aberration and the most frequent genetic cause of developmental delay. Both boys and girls are affected and have characteristic craniofacial and musculoskeletal features, as well as multiple medical anomalies involving the cardiac, gastrointestinal, ocular, and auditory systems. Down syndrome (Trisomy 21)” by U.S. Department of Energy Human Genome Genome The complete genetic complement contained in the DNA of a set of chromosomes in a human. The length of the human genome is about 3 billion base pairs. Basic Terms of Genetics Program. License: Public DomainPartial karyotype Karyotype The full set of chromosomes presented as a systematized array of metaphase chromosomes from a photomicrograph of a single cell nucleus arranged in pairs in descending order of size and according to the position of the centromere. Congenital Malformations of the Female Reproductive System of a myeloid cell from the bone marrow Bone marrow The soft tissue filling the cavities of bones. Bone marrow exists in two types, yellow and red. Yellow marrow is found in the large cavities of large bones and consists mostly of fat cells and a few primitive blood cells. Red marrow is a hematopoietic tissue and is the site of production of erythrocytes and granular leukocytes. Bone marrow is made up of a framework of connective tissue containing branching fibers with the frame being filled with marrow cells. Bone Marrow: Composition and Hematopoiesis of an individual with chronic myeloid leukemia Chronic myeloid leukemia Chronic myeloid leukemia is a malignant proliferation of the granulocytic cell line characterized by a fairly normal differentiation. The underlying genetic abnormality is the Philadelphia chromosome, an abbreviated chromosome 22, resulting from reciprocal (9;22)(q34;q11) translocation. Chronic Myeloid Leukemia: The image demonstrates t(9:22) translocation, also known as the Philadelphia chromosome Philadelphia chromosome An aberrant form of human chromosome 22 characterized by translocation of the distal end of chromosome 9 from 9q34, to the long arm of chromosome 22 at 22q11. It is present in the bone marrow cells of 80 to 90 percent of patients with chronic myelocytic leukemia. Acute Lymphoblastic Leukemia (bottom portion of chromosome Chromosome In a prokaryotic cell or in the nucleus of a eukaryotic cell, a structure consisting of or containing DNA which carries the genetic information essential to the cell. Basic Terms of Genetics 22 and chromosome 9 Chromosome 9 Friedreich’s Ataxia are switched (arrows)).
Image: “ BONE MARROW Bone marrow The soft tissue filling the cavities of bones. Bone marrow exists in two types, yellow and red. Yellow marrow is found in the large cavities of large bones and consists mostly of fat cells and a few primitive blood cells. Red marrow is a hematopoietic tissue and is the site of production of erythrocytes and granular leukocytes. Bone marrow is made up of a framework of connective tissue containing branching fibers with the frame being filled with marrow cells. Bone Marrow: Composition and Hematopoiesis: CHRONIC MYELOID LEUKEMIA Chronic myeloid leukemia Chronic myeloid leukemia is a malignant proliferation of the granulocytic cell line characterized by a fairly normal differentiation. The underlying genetic abnormality is the Philadelphia chromosome, an abbreviated chromosome 22, resulting from reciprocal (9;22)(q34;q11) translocation. Chronic Myeloid Leukemia: PHILADELPHIA CHROMOSOME Philadelphia chromosome An aberrant form of human chromosome 22 characterized by translocation of the distal end of chromosome 9 from 9q34, to the long arm of chromosome 22 at 22q11. It is present in the bone marrow cells of 80 to 90 percent of patients with chronic myelocytic leukemia. Acute Lymphoblastic Leukemia” by The Armed Forces Institute of Pathology (AFIP). License: Public DomainChromosomal microarray analysis is a high-resolution technique that utilizes fluorescent tags to identify small chromosomal imbalances.
A technique in which a fluorescent DNA DNA A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine). DNA Types and Structure (or RNA RNA A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. RNA Types and Structure) probe Probe A device placed on the patient’s body to visualize a target Ultrasound (Sonography) is utilized to identify and locate specific genes Genes A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms. DNA Types and Structure on chromosomes Chromosomes In a prokaryotic cell or in the nucleus of a eukaryotic cell, a structure consisting of or containing DNA which carries the genetic information essential to the cell. DNA Types and Structure
Female human karyotype Karyotype The full set of chromosomes presented as a systematized array of metaphase chromosomes from a photomicrograph of a single cell nucleus arranged in pairs in descending order of size and according to the position of the centromere. Congenital Malformations of the Female Reproductive System subjected to FISH with a probe Probe A device placed on the patient’s body to visualize a target Ultrasound (Sonography) to the Alu sequence (green) and counterstained for DNA DNA A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine). DNA Types and Structure (red)
Image: “ChromosomesAluFish” by Dietzel65. License: CC BY 2.5