(F) Clinical Cytogenetics (transes-based) Flashcards
Cytogenetic abnormalities may be found in all of these except:
A. Physiological healthy individuals
B. Normal genetic inheritance
C. Diagnosed genetic disorders
D. Individuals with phenotypic anomalies
B
T or F. Diagnosis of cytogenetic disorders may be made at any stage of life.
T
Diagnosis of cyto disorders are made before birth or in the womb of the mother.
Prenatal cytogenetics
Diagnosis of cyto disorders are made when the baby is born.
Postnatal cytogenetics
Diagnosis of cyto disorders are made during their developmental stage of life.
Childhood and adult cytogenetics
established if the same set of features are seen in several unrelated individuals; assumed to
have a common basis of specific chromosomal abnormalities but may occur in different degrees
syndrome
T or F. Syndromes are usually multifactorial, it is not commonly caused by a common/single-specific chromosomal
abnormality.
F
T or F. Syndromes may be mild, moderate or have severe manifestation.
T
Prenatal Cytogenetics TOF
50%-60% of spontaneous abortions during the early months of pregnancy have a demonstrable chromosomal abnormality
T
Prenatal Cytogenetics TOF
80% of which are autosomal trisomies
F (52)
Prenatal Cytogenetics TOF
1:3 conceptuses (embryo in the uterus) have chromosomal abnormality but seen only in 6:1000 live births due to biological elimination of recognized errors
T
even tho 1 out of 3, most of them are dropped hence 6:1000 and if u do the math 327 are dead for every 1000 ata
Rate of biological elimination TOF
45, X has the lowest rate of elimination
F (95%; Turner’s syndrome)
Rate of biological elimination TOF
90% of Trisomy 13
T (Patau Syndrome)
an extra copy of chromosome 13; characterized by cleft lip, cleft palate, cerebral defects, anophthalmia, simian creases, polydactyly, trigger thumbs, and capillary hemangiomata
Rate of biological elimination TOF
80% of Trisomy 18
T (Edwards Syndrome)
most babies with Edwards’ syndrome will die before or shortly after being born because it causes physical growth delays during fetal development
Rate of biological elimination TOF
90% of trisomy 21
F (65%; down syndrome)
T or F. as the number of chromosomes
goes higher the chances of being born alive is greater
T
Trisomy 21 has a lower biological elimination than Trisomy 13
TOF. as the number of chromosome goes lower, the larger the size of the chromosome and vice versa
T
TOF. the degree of biological elimination is directly proportional to the chromosome number while the degree of survival is inversely proportional.
F (opposite)
the degree of biological elimination is INDIRECTLY proportional to the chromosome number while the degree of survival is DIRECTLY proportional.
T or F. 15% of recognized pregnancies end in DELIBERATE fetal loss
F (sponty)
TOF. THIRD TRIMESTER is the time when
you have the highest number of spontaneous fetal loss
F (80% during first)
most common trisomy seen in abortus
Trisomy 16
TOF. Direct correlation between advanced PATERNAL age (>35 y/o) and incidence of chromosomal abnormalities, the most common being Down’s syndrome
F (Maternal malamang)
Performed on cells obtained by? Get sample from the placenta
On chorionic villus biopsy
Performed on cells obtained by? Get blood sample from a cord that joins the baby to the placenta
On umbilical cord blood
What do you call when you get a sample from amniotic fluid and then test the cells you get from there for karyotypic abnormalities
amniocentesis
TOF. All of the procedures performed on cells obtained from the mother are NONINVASIVE.
F (invasive)
The procedure done on the mother can only be done by?
A. obstetrician
B. medical technologist
C. midwifery
D. pathologist
A
fetal protein that is usually associated (if elevated) with neural tube defect
Alpha fetoprotein
This give rise to the brain and spinal
cord so if the AFP is elevated there is a
possibility that the baby could have a cranial
or spinal abnormality
neural tube
TOF. The first ultrasound is done on the 3rd month.
F (as soon as the mother consults for pOSSIBLE pregnancy)
TOF. The next ultrasound is done 5th or the 7th month of pregnancy
T
5th month (2nd trimester)
7th month (3rd trimester)
TOF. X-linked genetic disorders are usually manifested by FEMALES.
F (males kasi carriers ang mothers)
Forms of Neural Tube Defects
Completely open brain and spinal cord.
CRANIORACHISCHISIS
Forms of Neural tube defects
Open brain and lack of skull vault
Anencephaly
Forms of Neural Tube Defects
Herniation of the meninges and brain
encephalocele
Forms of Neural Tube Defects
ang tumawa bading
INIENCEPHALY
Occipital skull and spine defects with extreme
retroflexion of the head.
Forms of Neural Tube Defects
Closed asymptomatic neural tube defect (NTD)
in which some of the vertebrae are not
completely closed.
Spina Bifida Occulta
Forms of Neural Tube Defects
Deficiency of at least two vertebral arches.
CLOSED SPINAL DYSRAPHISM
What neural tube defect has a lipoma present which is a tumor of adipose tissue that blocks the opening
Closed spinal dysraphism
Neural Tube Defect
Protrusion of the meninges filled with CSF,
through a defect in the skull or spine.
MENINGOCELE
NTD
Open spinal cord with a meningeal cyst.
MYELOMENINGOCELE
TOF. INHERITED ARRANGEMENT poses less risk for related impairment than DE NOVO inheritance but may recur in future pregnancies.
T
This is done on both biological parents is to differentiate between an inherited rearrangement and a “de novo” anomaly in the child
Karyotype analysis
TOF. There’s a risk of related impairment, if the abnormalities are hereditary.
F (the only abnormality is what is inherited)
Which are not indication of prenatal cytogenetics
A. Carrier of unbalanced gametes
B. Carrier of X-linked genetic disorder
C. Family history with Chromosomal abnormality
D. Suspected aneuploidy
E. Abnormal levels of AFP in screening test
D
T or F. Approximately less than 1% of all newborns have a gross chromosomal abnormality.
T (.6%-1%)
postnatal cyto
If a newborn infant presents with manifestations of
a syndrome, a karyotype analysis is needed to except?
A. Confirm diagnosis
B. Screening of AFP
C. Proving assumption
D. Finding of abnormalities
B
Pre or Post
Presence of multiple congenital anomalies
Post
Pre or Post
features of Down
syndrome
Post
TOF. Some genetic disorders manifest in later life.
T
TOF. molecular and biochemical studies may be needed in post natal cyto as it poses more difficult diagnostic problems.
F (emphasized more on child and adult cyto)
it’s probably because the disorder become more significant and serious
Which does not belong
A. Infertility
B. Multiple sponty aborts
C. Unsuspected sex chromosomal abnormality
D. Suspected Prader-Willi syndrome (obese)
E. Suspected fragile - X syndrome
C (suspected)
Adult and Child Cyto
has an insatiable appetite caused by a defect in the hypothalamus that causes the person to never actually feel full.
Prader-Willi Syndrome
What chromosome has a defect in prader-willi syndrome?
15
T or F. In Prader-Willi Syndrome, people who have this have a higher threshold for pain and boughts of rage.
T (real)
defect on the hypothalamus (involved in the expression of emotions)
Which is not part of the Prader-Willi Syndrome
A. Stealing
B. Eating pet foods and spoiled items
C. Psychoses
D. Compulsive
E. Delayed development
E
TOF. In cancer genetics, there’s a DIRECT correlation between the presence of various chromosomal abnormalities and patient’s response to treatment
T
now a requirement for final diagnosis of most hematological disorders
genetic findings
T or F. Cancers are usually caused by GENETIC MUTATIONS.
T
This is directly associated with certain
chromosomal abnormalities, and are usually best appreciated in patients with leukemia
tumorigenesis
TOF. In cancer, the nomenclature is now based on which chromosome has been deleted, amplified, or fused
T (leukemia)
Indications for cancer cytogenetics include:
You do karyotyping and FISH in order to identify if the particular chromosomal abnormalities is actually present or not, if it is present then it confirms your diagnosis
Confirm a clinical diagnosis
Indications for cancer cytogenetics include:
You do other studies to rule out the presence
of the disease
confirm clinical diagnosis
TOF. The absence of one karyotypic abnormality
does completely rule out deletion
F
Indications for cancer cytogenetics include:
associated with karyotype evolution which implies an increasing karyotypic complexity (appearance of additional chromosomal aberrations and/or more complex cell lines) overtime
Monitor disease progression - relapse anddisease progression
Indications for cancer cytogenetics include:
cytogenetic remission
Monitor patients’ response to therapy - successful
treatment results in cytogenetic remission
a patient no longer has evidence of cells with the chromosomal abnormalities after going treatment
cyto remission
valuable tool in clinical oncology studies
FISH (fluorescent in situ hybridization)
Cell cycle
What phase of cells are used for testing?
interphase or metaphase
This phase in the cell cycle provide a much larger sample resulting in a higher statistical significance
interphase
Combination of FISH probes have also been developed for translocations which results in?
fusion and splitting
segments of 2 different chromosomes switched places
balanced translocation
a normal male with a break in the long arm of chromosome 4, region 2, band 1, and sub-band 1 switches places with a break in the short arm of chromosome 9, region 2, band 2
ANONG TRANSLOCATION YAN
balanced translocation
type of translocation:
usually occurs in acrocentric chromosomes (centromeres are near the end)
Robertsonian translocation/centric fusion
the two long arms broke with the centromere, and then joined together, the two long arms joined
together and the two short arm also joined together but during cell division
ANONG TRANS
RObertsonian
The two short arms are lost during cell division because it is not attached to the spindle, but the two long arms are retained
occur if the translocation
results in separation of two probes generating two-different colored signals in place of the original single-color signal
splitting
occur in the translocation results in relocation of two different probes into proximity causing generation of a new color
Fusion
detects all nucleated cells both normal and
abnormal, thus provide a more accurate estimate of disease involvement within the total population
FISH
can only be performed on dividing cells, since cancer cells are continuously dividing, analysis will usually show 100% abnormal cells
karyotyping
TOF. It is important to perform either FISH or karyotyping for diagnosis
F (perform both
- karyotype will identify the chromosomal abnormalities
- FISH will establish the baseline
frequency of leukemic clones which can
be used as reference point for all of the
patients’ future testing
TOF. cancer cells undergo
a significantly greater degree of chromosome rearrangement which may give clues to new cancer-related gene
T
Post Test
Which of the following is true of a syndrome?
a) Consist of the same group of chromosomal abnormalities
b) Abnormalities present in the same degree
c) Observed in the same group of people
d) Arise from different forms of chromosomal abnormalities
A
Post-Test
Genetic abnormalities is NOT seen in which of
the following individuals?
a) Seemingly normal
b) With gross deformities
c) With confirmed genetic disorder
d) None of these
d
Post-Test
Although chromosomal abnormalities are present in 1:3 conceptus, only 6:1000 livebirths manifest the disorder. Which of the following explains this low incidence at birth?
a) Repair mechanism of recognized errors
b) Biologic elimination of recognized errors
c) Poor identification of genetic abnormalities
d) Low interest on genetic abnormalities
B
Post-Test
Which of the following is the most common chromosomal abnormalities seen in spontaneous abortion?
a) 47, XY, +13
b) 47, XY, +18
c) 47, XY, +21
d) 45, X
D
Post-Test
Which of the following specimens is not used for prenatal cytogenetic testing?
a) Umbilical cord blood
b) Chorionic villi
c) Amniotic fluid
d) Fetal bladder aspirate
D
Post-Test
The incidence of fetal loss among patients with genetic abnormalities is greatest during which of the following phase of pregnancy?
A.1st trimester
B. 2nd trimester
C. 3rd trimester
D. Newborns
A
item 6
Most miscarriages happen because the unborn baby doesn’t develop properly. About half to two-thirds of miscarriages in the first trimester are linked with extra or missing chromosomes, according to Mayo Clinic.
Post-Test
Which of the following groups of mothers have the highest tendency to have cytogenetically abnormal progeny?
a) Less than 25 yrs old
b) 26-30 yrs old
c) 31-35 yrs old
d) More than 35 yrs old
D
Post-Test
Which of the following is an indication for prenatal cytogenetics?
a) Presence of multiples congenital anomalies
b) Unexplained mental retardation
c) An abnormal level of alpha-fetoprotein (AFP)
d) Suspected aneuploidy
C
Post-Test
Which of the following relationships has not been established between cancer and genetics?
a) Specific chromosomal rearrangements are directly associated with tumor formation
b) Direct correlation exists between presence of various chromosomal abnormalities and therapeutic response
c) Genetic findings are now required in the diagnosis of most ematopoietic cancers
d) None of these
D
item no. 9
Post-Test
Philadelphia chromosome or abl-bcr fusion gene is a diagnostic of which of the following hematopoietic malignancy?
a) Acute myelogenous leukemia
b) Acute lymphoblastic leukemia
c) Chronic myelogenous leukemia
d) Chronic lymphocytic leukemia
C
Translocation is seen in, except:
A. chronic myeloid leukemia (CML)
B. chronic lymphoblastic leukemia (CLL)
C. acute myeloid leukemia (AML)
D. acute lymphoblastic leukemia (ALL)
B
This disease translocation is similar to CML only difference is that there is no sub-band in the long arm of region 3 band 4
acute lymphoblastic leukemia (ALL)
ALL - t(9;22)(q34;q11.2)
CML - t(9;22)(q34.1;q11.2)
translocation in CML involves the ABL protooncogene on chromosome?
9 (9q34.1)
t(9;22)(q34.1;q11.2)
translocation in CML involves
the BCR gene on chromosome?
22
t(9;22)(q34.1;q11.2)
translocation in CML involves the ABL
protooncogene and the BCR gene producing a disease-associated chimeric gene on chromosome?
derivative chromosome 22 (Philadelphia chromosome, Ph’)
method uses a pair of probes
ABL locus on chromosome 9 is what color indicator?
Red
method uses a pair of probes
What color indicator is produced for the BCR locus on chromosome 22?
Green
T or F. Normal chromosome will give two green and no red signals for the ABL and BCR alleles in each cell.
F (2 green and 2 red to become normal)
The yellow signal formed is an indicator of what?
BCR-ABL fusion gene
Philadelphia chromosome is diagnostic of?
chronic myelogenous leukemia (CML)
The probe (choromosome 7) is used to detect for chromosomal abnormality for diseases, except:
A. MDS
B. CLL
C. AML
B
MDS (Myelodysplastic syndrome),
AML (Acute Myeloid Leukemia)
CLL (chronic lymphocytic leukemia) is for Trisomy 12
X and Y probes is used for what chromosomal abnormality?
For BM transplanatation of Male from Female
This is to Monitor Success, monitor treatment
What probe is used for acute and chronic disorders?
Chromosome 8 (for trisomy 8)
In BM transplantation (patient Male, donor Female), the following are indicators that the treatment will become successful, except:
A. no more XY cells in the
patient’s bone marrow
B. the bone marrow of this female (XX) will proliferate in the BM of this male patient
C. there’s only the presence XX bone marrow cells (red cells, granulocytes, WBC)
D. The donor cells grew
E. NOTA
E
T or F. If you find XY cells in the MALE patient, the transplantation was not successful
T
