Structural Aberrations Flashcards
This is the meaning for ISCN.
International System for Human Cytogenetic Nomenclature
This is the concept wherein each area of chromosomes is given a number.
ISCN
This is the lowest number closes to the centromere.
Proximal
This is the highest number at the tip to the centromere.
Distal
This is how to read 3p22.
3p = 3rd Chromosome
2 = 2 band
2 = 2 sub-band
chromosome:band:sub-band
This is the meaning behind ptel and qtel.
“Tel” means telomere and p and q dictates which arm is being referred to.
This is the result from breakage of a chromosome region with loss or subsequent rejoining in an abnormal combination.
Structural Abnormalities
This general type of structural abnormality is based on the no loss or gain of genetic chromatin.
Balanced Rearrangements
This general type of structural abnormality is based on the gain or loss of genetic material.
Imbalanced Rearrangement
This rearrangement is the change in chromosomal gene order but do not remove or duplicate any of the DNA of the chromosomes.
Balanced Rearrangement
This rearrangement is changing the gene dosage of a part of the affected chromosome.
Imbalanced Rearrangement
This is the type of rearrangement when a chromosome is translocated or inverted.
Balanced Rearrangement
This is the type of rearrangement when a chromosome is deleted or duplicated.
Imbalanced Rearrangement
This type of aberration wherein a segment from a chromosome is transferred to another.
Translocation
This is a type of aberration wherein a segment of a chromosome is inverted.
Inversion
This is a type of aberration wherein a segment of a chromosome is lost.
Deletion
This is a type of aberration wherein a segment from one chromosome is transferred to its homologous chromosome.
Duplication
These are the reasons why structural aberrations may occur.
Errors during meiosis, mitosis, or exposure to substances (teratogens).
These are substances that causes congenital disorders.
Teratogens
This structural rearrangement is when a segment of a chromosome is reversed end to end.
Inversions
True or False: Inversions occur when 2 chromosomes undergo breakage and rearrange each other.
False, only single chromosomes undergo inversion within itself.
True or False: Inversion is inherited, or it can be a mutation that appears in a child whose family has no history.
True
True or False: Inversions is undetectable in the structure of a chromosome.
False, sometimes they can be seen in chromosome structure.
This type of inversion involves the centromere.
Pericentric Inversion
This type of inversion does not include the centromere.
Paracentric Inversion
This is one of the most common structural balanced chromosomal variants.
Chromosome 9 Inversion
These are cases associated with the inversion of the 9th chromosome.
Cancer (acute myeloid leukemia), congenital anomalies, infertility, growth retardation, and pregnancy lost.
This is the type of inversion the 9th chromosome inversion is.
Pericentric Inversion
This when a chromosome is deleted or missing.
Deletion
These are the two types of chromosome deletion.
Interstitial and Terminal Deletion
These are the other terms for the Cri-du-chat Syndrome.
5P Minus and Lejeune’s Syndrome
This is the year and the one who discovered the Cri-du-chat Syndrome.
Jerome Lejeune in 1963
This is the chromosome that gets deleted in the Cri-du-chat Syndome.
Chromosome 5
This gene in the Cri-du-chat is responsible for DNA functioning.
HTERT gene
This gene in the Cri-du-chat is responsible for cell adhesion, cell movement, and active NS.
CTNND2 gene
This genetic aberration has features like high-pitched cat like cry, low birth weight, microcephaly, eyes wide apart, folds of skin over eyelids, palate abnormality, and ear malformity.
Cri-du-chat Syndrome
This associative disorder is described as having an abnormally small head.
Microcephaly
This is the deletion of the distal p arm of chromosome 4.
Wolf-Hirschhorn Syndrome
This is the year and the one who discovered the Wolf-Hirschhorn Syndome.
Hirschhorn and Cooper in 1961
This gene in the WH Syndrome is responsible for the distinctive facial appearance and development delay.
NSD2 gene
This gene in the WH Syndrome is responsible for seizures or other abnormal electric brain activity.
LETM1 gene
This gene is the WH Syndrome is responsible for dental abnormalities and cleft lip/palate.
MSX1 gene
This genetic aberration features a broad, flat nasal bridge and high forehead resembling a Greek warrior’s helmet. Also features stunted growth and development, and delayed motor skills.
Wolf-Hirschhorn Syndrome
This is the normal form of gene regulation that causes a subset of genes to be expressed from one of the two parental chromosomes.
Genomic Imprinting
True or False: Only a handful of genes inherit working copies (one from mother and one from father).
False, most of the genes inherit working copies.
True or False: Imprinting mostly involves one working copy from either parent.
True
True or False: Genomic imprinting is epigenetically silenced.
True
This is the reason silencing occurs in a gene through the addition of methyl groups during sperm and egg formation.
DNA Methylation
This genetic aberration is due to the absence of the chromosome region 15.
Angelman Syndrome
True or False: The Angelman Syndrome is due to the mutation of the UBE2A gene in the paternal chromosome 15 (q12)
False, the mutation is on the UBE3A gene in the maternal chromosome 15 (q12).
This is the year and the one who discovered the Angelman Syndrome.
Harry Angelman in 1965
This genetic aberration features delayed development, movement/balance disorder, behavioral uniqueness, and speech impairment.
Angelman Syndrome
True or False: Prader-Willi Syndrome occurs from the absence of the maternal genes from chromosome 15q11-q15.
False, it occurs from the absence of the paternal gene chromosome 15q11-q13.
This is the year and the one who discovered the Prader Willi Syndrome.
Prof. A. Prader, A. Labhart, and H. Willi in 1956
This genetic aberration features hypotonia, hypogonadism, obesity, and CNS & endocrine gland dysfunction.
Prader-Willi Syndrome
This associative disorder is described as a decrease in muscle tone due to muscle dystrophy or cerebral palsy.
Hypotonia
This associative disorder is described to occur when the body’s sex glands produce little to no hormones.
Hypogonadism
This type of ring chromosome is the result from breakage and reunion of a single chromosome with loss of chromosomal material outside the break points.
Double Strand Breaks
This type of ring chromosomes is described when one or both telomeres may join to form a ring without significant loss of materials.
Telomere Dysfunction
This type of ring chromosome also occurs when a broken end of a telomere fuses together to form a ring.
Telomere Dysfunction
This genetic aberration features seizures and intellectual disability caused by epilepsy.
Ring Chromosome 14 Syndrome
True or False: Ring Chromosome 14 Syndrome is caused by a double strand break.
False, it is caused by a telomere dysfunction.
This a type of structural aberration occurs due to a partial trisomy for only part of a chromosome.
Duplication
True or False: Duplications is only present during cells that undergo mitosis.
False, both mitosis and meiosis can form unbalanced insertions or unequal crossovers due to duplication.
This type of structural aberration arises from either abnormal division of the centromeres.
Isochromosomes
This type of structural aberration results in each daughter cells duplicates either p arm or q arm.
Isochromosomes
True or False: Isochromosomes undergo vertical division.
False, they undergo horizontal division.
This type of structural aberration involves the movement of a chromosomal segment from one location to another of the same or another chromosome.
Insertions
This type of structural aberration occurs when a chromosome breaks into two pieces and each piece reunites with another non-homologous chromosome.
Translocation
True or False: A balanced translocation happens when a chromatin is neither lost nor gained in the exchange.
True
True or False: An unbalanced translocation happens when there is a loss or gain of chromatin material that results in complete monosomy or trisomy of a chromosome segment.
False, the loss/gain would only produce a partial trisomy or monosomy.
This is an example of an unbalanced translocation wherein majority of chromosome 21 is attached to chromosome 14.
Down Syndrome
This is a type of translocation wherein parts of two chromosomes breaks off and reattaches to each other’s broken ends.
Reciprocal Translocation
This type of structural aberration occurs when the centromeres of two acrocentric chromosomes fuse to generate one large chromosome.
Robertsonian Translocation
True or False: Translocation is when genetic material is added from another chromosome while insertion is genetic material swapped with another chromosome.
False, insertion is genetic material added to another chromosome and translocation is swapped.