Block 15 Genetic Pathology
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Chromosomes involved in Robertsonian translocations?
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Ring
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Holocentric
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Submetacentric
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Acrocentric
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Metacentric
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Block 15 Genetic Pathology quiz assesses knowledge on chromosomal disorders including Robertsonian translocations, aneuploidy, and medical impacts of balanced translocations. It explores genetic disorders' late manifestations and common chromosomal aberrations leading to fetal death, crucial for advanced genetics and medical studies.
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- 2.
47XY, +21 karyotype represents … (more than one correct answer possible)
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Haploid set
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Euploid set
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Diploid set
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Aneuploid set
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Isochromosome
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Trisomy
Correct Answer(s)
A. Aneuploid set
A. TrisomyExplanation
The given karyotype, 47XY, +21, represents an aneuploid set and trisomy. Aneuploidy refers to an abnormal number of chromosomes, either an extra or missing chromosome. In this case, the presence of an extra chromosome 21 (+21) indicates trisomy 21, which is commonly known as Down syndrome. Trisomy refers to the presence of an extra copy of a chromosome, resulting in a total of three copies instead of the usual two. Therefore, both aneuploid set and trisomy accurately describe the given karyotype.Rate this question:
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- 3.
The major cause of infertility in Turner syndrome …
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A. Polycystic ovaries
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B. Uterine malformation
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C. Loss of sexual desire
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D. Early loss of oocytes (before puberty)
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E. Blockage of fallopian tubes
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F. Absence of internal genitalia
Correct Answer
A. D. Early loss of oocytes (before puberty)Explanation
The correct answer is D. Early loss of oocytes (before puberty). Turner syndrome is a genetic disorder that affects females and is characterized by the absence or abnormality of one of the X chromosomes. This condition can cause the ovaries to not develop properly, leading to a decrease in the number of eggs available for fertilization. As a result, many women with Turner syndrome experience infertility due to the early loss of oocytes, which occurs before puberty. This is a major cause of infertility in individuals with Turner syndrome.Rate this question:
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- 4.
Muscle hypotonia and cardiomegaly in infancy are associated with …
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Serum accumulation of amino acids
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Lysosomal accumulation glycosaminoglycans
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Lysosomal accumulation of glycogen
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Cytosolic accumulation of glycogen
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Lysosomal accumulation of lipids
Correct Answer
A. Lysosomal accumulation of glycogenExplanation
Muscle hypotonia refers to decreased muscle tone, which can result in weak muscle strength and difficulty with movement. Cardiomegaly refers to an enlarged heart. Both of these conditions in infancy are associated with lysosomal accumulation of glycogen. Lysosomes are cellular organelles responsible for breaking down various substances, including glycogen. When there is a defect in the enzymes responsible for breaking down glycogen in lysosomes, glycogen accumulates within the lysosomes, leading to the symptoms of muscle hypotonia and cardiomegaly.Rate this question:
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- 5.
The shown electron microphotograph is characteristic for :
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Marfan syndrome
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Ehlers- Danlos syndrome
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Gaucher disease
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Tay-Sachs disease
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Hurler disease
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Hunter disease
Correct Answer
A. Tay-Sachs diseaseExplanation
The electron microphotograph shown is characteristic for Tay-Sachs disease. Tay-Sachs disease is a genetic disorder characterized by the accumulation of a fatty substance called GM2 ganglioside in the cells of the brain and nervous system. The electron microphotograph shows the presence of characteristic membranous bodies, known as lamellar bodies, which are a hallmark feature of Tay-Sachs disease. These bodies are formed due to the accumulation of GM2 ganglioside in the lysosomes of cells.Rate this question:
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- 6.
Major causes of death of patients with Marfan syndrome? (more than one correct answers)
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A. Bone weakness and repetitive fractures
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B. Poor wound healing and secondary infection
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C. Dissecting aortic aneurysm and its rupture
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D. Mitral valve prolapse and heart failure
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E. Reduced vision with multiple falls and head trauma
Correct Answer(s)
A. C. Dissecting aortic aneurysm and its rupture
A. D. Mitral valve prolapse and heart failureExplanation
Patients with Marfan syndrome are at an increased risk of developing a dissecting aortic aneurysm and its rupture. This is because the syndrome affects the connective tissue, including the walls of the aorta, making it weaker and more prone to rupture. Additionally, mitral valve prolapse and heart failure are also common causes of death in patients with Marfan syndrome, as the syndrome can affect the structure and function of the heart valves.Rate this question:
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- 7.
Genetic disorders … (More than one correct answer possible)
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Are always inherited from parents
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Are always inborn
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Are always manifested at birth
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May delay with manifestations till late adulthood
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May result from spontaneous mutations in gametes
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May result from spontaneous mutations in embryonic somatic cells
Correct Answer(s)
A. May delay with manifestations till late adulthood
A. May result from spontaneous mutations in gametes
A. May result from spontaneous mutations in embryonic somatic cellsExplanation
Genetic disorders may delay with manifestations till late adulthood because some genetic disorders have a late onset and may not show symptoms until later in life. They may result from spontaneous mutations in gametes because genetic mutations can occur randomly during the formation of reproductive cells. They may also result from spontaneous mutations in embryonic somatic cells because genetic mutations can occur during early stages of development in the embryo.Rate this question:
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- 8.
Cataract in infancy is associated with …
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A. Phenylketonuria
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B. Galactosemia
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C. Cystic fibrosis
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D. Hemolytic disease of the newborn
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E. Gaucher disease
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F. Hurler disease
Correct Answer
A. B. GalactosemiaExplanation
Cataract in infancy is associated with Galactosemia. Galactosemia is a genetic disorder that affects the body's ability to break down galactose, a sugar found in milk and dairy products. When galactose builds up in the body, it can cause various health problems, including cataracts. Cataracts are clouding of the lens in the eye, leading to blurry vision or vision loss. Therefore, the presence of cataracts in infancy can be an indication of Galactosemia.Rate this question:
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- 9.
The most common prenatal diagnostic sign in Down syndrome?
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Palmar crease
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Epicanthic fold
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Upslanting eyes
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Increased nuchal translucency
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Abnormal serum PAPP-A
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Abnormal serum beta-hCG
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Abnormal serum AFP
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Abnormal serum estradiol
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Abnormal serum inhibin A
Correct Answer
A. Increased nuchal translucencyExplanation
http://www.monashultrasound.com.au/images/pg10_b.jpgRate this question:
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- 10.
The shown pathology is characteristic for … (more than one correct answer)
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A. Angelman syndrome
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B. Prader-Willi syndrome
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C. DiGeorge syndrome
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D. Hurler disease
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E. Hunter disease
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F. Velocardiofacial syndrome
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G. Fragile X chromosome
Correct Answer(s)
A. C. DiGeorge syndrome
A. F. Velocardiofacial syndromeExplanation
Velocardiofacial syndrome (VCFS) is a genetic condition characterized by abnormal pharyngeal arch development that results in defective development of the parathyroid glands, thymus, and conotruncal region of the heart.
Affected individuals may present with structural or functional palatal abnormalities, cardiac defects, unique facial characteristics, hypernasal speech, hypotonia, and defective thymic development.
An estimated 75% of patients with velocardiofacial syndrome have cardiac anomalies. The cardiac defects are usually of the conotruncal type, which occur secondary to abnormal development of the outflow portion of the developing heart. The most common cardiac defects include interrupted aortic arch type B (50%), truncus arteriosus (34.5%) and tetralogy of Fallot (16%). Other cardiac defects include pulmonary atresia with ventricular septal defect, absent pulmonary valve syndrome, ventricular septal defect (especially when accompanied by aortic arch anomalies), aortic stenosis, anomalies of the aortic arch or its major branches, and pulmonary artery anomalies
Palatal abnormalities predispose to speech and feeding difficulties.
The defective thymic development is associated with impaired immune function. This condition not only predisposes to an increased risk of infection but also predisposes some individuals to develop autoimmunity. Parathyroid and immune deficiencies can progress or resolve with time.
In addition, affected individuals may present with learning disabilities, overt developmental delay, psychiatric disorders, and renal and musculoskeletal defects.
Ophthalmologic abnormalities are seen in 70% of patients with velocardiofacial syndrome, such as posterior embryotoxon, bilateral cataracts, tortuous retinal vessels, and small optic disks. Other rare anomalies include congenital absence of the nasolacrimal duct.
About 10% of patients with velocardiofacial syndrome have DIGEORGE SYNDROME, which consists of at least 2 of the following features:
• Conotruncal cardiac anomaly
• Hypoparathyroidism, hypocalcemia
• Thymic aplasia, immune deficiency
•Rate this question:
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- 11.
What is true about life span in Gaucher disease?
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A. Shorter due to multiple bone fractures and associated pathology
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B. Shorter due to bone marrow atrophy
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C. Shorter due to liver failure
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D. Shorter due to splenic rupture
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E. Not affected
Correct Answer
A. E. Not affectedExplanation
Gaucher disease is a genetic disorder that affects the metabolism of certain fats in the body. It is caused by a deficiency of an enzyme called glucocerebrosidase. While Gaucher disease can cause a range of symptoms, including enlarged liver and spleen, anemia, and bone problems, the life span of individuals with Gaucher disease is not affected. With proper management and treatment, individuals with Gaucher disease can live a normal life span.Rate this question:
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- 12.
Two daughter cells after anaphase lag are … (more than one correct answer possible)
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Both euploid
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Both aneuploid
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One euploid, another aneuploid
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One euploid and another monosomic
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One euploid and another trisomic
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One monosomic and another trisomic
Correct Answer(s)
A. One euploid, another aneuploid
A. One euploid and another monosomic -
- 13.
Medical significance of balanced translocations? (More than one correct answer possible)
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Not significant
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May cause neoplastic growth
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May cause partial aneuploidy in offspring
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Incompatible with life
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May cause infertility
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May cause mental retardation
Correct Answer(s)
A. May cause neoplastic growth
A. May cause partial aneuploidy in offspringExplanation
Balanced translocations can have medical significance as they can lead to various outcomes. They may cause neoplastic growth, which refers to the formation of tumors or cancerous cells. Additionally, they may cause partial aneuploidy in offspring, meaning there is an abnormal number of chromosomes in some cells. This can result in developmental abnormalities or genetic disorders. It is important to note that while these outcomes are possible, not all balanced translocations will necessarily lead to these effects.Rate this question:
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- 14.
Salty sweat in patients with CF is associated with … (more than one correct answer)
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CFTR mutation
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ENaC mutation
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Inhibition of ENaC
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Activation of ENaC
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Inhibition of bicarbonate transport
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Activation of bicarbonate transport
Correct Answer(s)
A. CFTR mutation
A. Inhibition of ENaCExplanation
Salty sweat in patients with CF is associated with CFTR mutation because CFTR is a protein that regulates the movement of chloride ions across cell membranes, including those in sweat glands. When CFTR is mutated, it leads to a defective chloride channel, causing an imbalance of ions in sweat and resulting in salty sweat. Inhibition of ENaC is also associated with salty sweat in CF patients because ENaC is a sodium channel that is overactive in CF, leading to excessive reabsorption of sodium and water in sweat glands, which further increases the saltiness of sweat.Rate this question:
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- 15.
What is true about sexual life of patients with Klinefelter syndrome? (more than one correct answers)
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A. No sexual desire
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B. Cannot ejaculate
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C. Vasa deferentia are blocked
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D. Azoospermia
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E. Testicles are atrophied
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F. Very low testosterone level
Correct Answer(s)
A. D. Azoospermia
A. E. Testicles are atrophiedExplanation
Patients with Klinefelter syndrome may experience azoospermia, which means they have no sperm in their ejaculate. Additionally, their testicles may undergo atrophy, meaning they become smaller and less functional. These two conditions can contribute to infertility in individuals with Klinefelter syndrome.Rate this question:
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- 16.
A genetic disease, which is NOT associated with mental retardation …
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Angelman syndrome
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Fragile-X syndrome
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Galactosemia
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Gaucher disease
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Klinefelter syndrome
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Phenylketonuria
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Prader-Willi syndrome
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Tay Sachs disease
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Velocardiofacial syndrome
Correct Answer
A. Gaucher diseaseExplanation
Gaucher's disease is a genetic disease in which a fatty substance (lipid) accumulates in cells and certain organs. Gaucher's disease is the most common of the lysosomal storage diseases. It is a form of sphingolipidosis (a subgroup of lysosomal storage diseases), as it involves dysfunctional metabolism of sphingolipids. The disorder is characterized by bruising, fatigue, anemia, low blood platelets, and enlargement of the liver and spleen. It is caused by a hereditary deficiency of the enzyme glucosylceramidase. The enzyme acts on the fatty acid glucosylceramide. When the enzyme is defective, glucosylceramide accumulates, particularly in white blood cells, most often macrophages (mononuclear leukocytes). Glucosylceramidase can collect in the spleen, liver, kidneys, lungs, brain and bone marrow.
Symptoms may include enlarged spleen and liver, liver malfunction, skeletal disorders and bone lesions that may be painful, severe neurologic complications, swelling of lymph nodes and (occasionally) adjacent joints, distended abdomen, a brownish tint to the skin, anemia, low blood platelets and yellow fatty deposits on the white of the eye (sclera). Persons affected most seriously may also be more susceptible to infection. Some forms of Gaucher's disease may be treated with enzyme replacement therapy.
The disease is caused by a recessive mutation in a gene located on chromosome 1 and affects both males and females. About 1 in 100 people in the United States are carriers of the most common type of Gaucher disease. The carrier rate among Ashkenazi Jews is 8.9% while the birth incidence is 1 in 450Rate this question:
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- 17.
The most common chromosomal aberration responsible for fetal death? (more than one correct answer possible)
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45X
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47XX, +21
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47XY, +18
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47XY, +16
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47XX, +13
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45X/46XY
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49XXXXY
Correct Answer(s)
A. 45X
A. 47XY, +16Explanation
Trisomy 16 is a chromosomal abnormality in which there are 3 copies of chromosome 16 rather than two. It is the most common trisomy leading to miscarriage and the second most common chromosomal cause of it, closely following X-chromosome monosomy. Like most chromosomal abnormalities, trisomy 16 usually causes miscarriage in the first trimester of pregnancy.
It is not possible for a child to be born alive with an extra copy of this chromosome present in all cells (called Full Trisomy 16). It is possible for a child to be born alive with the mosaic form
Despite the excellent postnatal prognosis, 99% of Turner-syndrome conceptions are thought to end in spontaneous abortion or stillbirth, and as many as 15% of all spontaneous abortions have the X,O karyotypeRate this question:
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- 18.
Conditions involved in development of azoospermia in Klinefelter syndrome? (more than one correct answers)
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A. Low-to-zero testosterone level
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B. Low FSH and LH level
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C. Low 5-alpha-reductase activity
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D. Low AR response to testosterone
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E. Low AR response to dihydrotestosterone
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F. Extended CAG repeats in AR gene
Correct Answer(s)
A. D. Low AR response to testosterone
A. E. Low AR response to dihydrotestosterone
A. F. Extended CAG repeats in AR geneExplanation
The development of azoospermia in Klinefelter syndrome can be attributed to the following conditions: low androgen receptor (AR) response to testosterone and dihydrotestosterone, as well as extended CAG repeats in the AR gene. These conditions can affect the normal functioning of the androgen receptor, leading to impaired sperm production and ultimately azoospermia.Rate this question:
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- 19.
Prader-Willi syndrome develops when … (more than one correct answer)
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PW gene is imprinted on maternal chromosome
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PW gene is imprinted on paternal chromosome
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PW gene on paternal chromosome is lost
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Both 15th chromosomes are maternal
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Both 15th chromosomes are paternal
Correct Answer(s)
A. PW gene is imprinted on paternal chromosome
A. PW gene on paternal chromosome is lost
A. Both 15th chromosomes are maternalExplanation
The correct answer is that Prader-Willi syndrome develops when the PW gene is imprinted on the paternal chromosome, the PW gene on the paternal chromosome is lost, and both 15th chromosomes are maternal. This means that the genes responsible for regulating appetite and hunger are affected, leading to excessive hunger and overeating, as well as other symptoms associated with Prader-Willi syndrome.Rate this question:
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.JPG "The shown pathology is characteristic for … (more than one correct answer)")
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Oct 26, 2012Quiz Created by
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