Chromosome Mutations and Karyotyping Techniques

This set of flashcards covers key concepts, techniques, and terminologies related to chromosome mutations and karyotyping techniques.

What is a chromosome?

A highly packaged structure of DNA that carries genetic information.

What does n represent in human cells?

The number of different chromosomes, which is 23 for humans.

What is the DNA content (C) for human cells?

3.5 picograms.

What is karyotyping?

A method to visualize and analyze the number and appearance of chromosomes.

What are the two types of chromosome aberrations?

Numerical aberrations and structural aberrations.

What is G-banding?

A staining technique used to visualize chromosomes, enhancing banding patterns for analysis.

What is the purpose of phytohemagglutinin (PHA) in cell culture?

To stimulate lymphocytes to divide before karyotyping.

What is aneuploidy?

An abnormal number of chromosomes, which can occur as monosomy or trisomy.

What is trisomy 21 commonly known as?

Down syndrome.

What causes Turner syndrome?

Monosomy of the X chromosome (45,X).

What are the characteristics of Klinefelter syndrome?

Presence of an extra X chromosome (47,XXY), leading to features like reduced fertility and tall stature.

What is the difference between pericentric and paracentric inversion?

Pericentric inversion involves the centromere; paracentric does not.

What is the significance of chromosome painting?

It utilizes probes to rapidly identify specific chromosomes or rearrangements.

What does CGH stand for?

Comparative Genomic Hybridization.

What results from non-disjunction during meiosis?

Aneuploidy, causing an abnormal distribution of chromosomes.

What are the effects of triploidy?

It involves three sets of chromosomes and often leads to fetal or neonatal death.

What is a Robertsonian translocation?

A fusion between two acrocentric chromosomes, resulting in a stable chromosome structure.

What are structural chromosome aberrations?

Changes in the structure of chromosomes, including deletions, duplications, inversions, and translocations.

What is the role of acetic acid and methanol in chromosome preparation?

To fix the chromosomes in place on the slides.

What is the role of denaturation in FISH?

To separate DNA strands to allow hybridization with fluorescent probes.

What does the term 'haploinsufficiency' refer to?

A situation where a single copy of a gene is insufficient to produce a normal phenotype.

What is the ratio of incidence for trisomy 18 (Edwards syndrome)?

1 in 3,000 live births.

What chromosome typical of 47,XY,+21 indicates?

A male individual with Down syndrome.

What is the function of a centromere in chromosomes?

To serve as the attachment point for spindle fibers during cell division.

What is a karyogram?

A photographic or digital image of an individual's chromosomes arranged in pairs.

What does Giemsa stain highlight in chromosome bands?

It stains AT-rich regions dark and GC-rich regions light.

What does 'isochromosomes' refer to?

Chromosomes that have identical arms due to unequal division.

What is the typical number of chromosomes in a typical human karyotype?

46 chromosomes.

What does the nomenclature '46,XX,del(5)(q13q33)' indicate?

A deletion on chromosome 5 from band q13 to q33.

What can microdeletions lead to?

Loss or dysregulation of multiple genes.

What type of chromosomes are involved in chronic myeloid leukemia?

BCR-ABL fusion resulting from a t(9;22) translocation.