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Flashcards in Snapp question Deck (111)

When should patient's with Turner's syndrome be transitioned to an adult primary care doctor and adult specialists?

during adolescence


Neonatal diagnosis of Turner's Syndrome is most often accompanied by anomalies in which organ?



A baby is born with prominent auricles, blue sclerae, and broad, widely spaced nipples. In utero, the baby had cystic hygromas and today you notice residual webbing of the neck. Which of the following is the most likely genetic finding in this patient?

a single X chromosome


Which of the following is included as standard treatment for Gaucher's disease?

enzyme replacement


What is the most significant disadvantage to utilizing non-viral genetic therapies during the treatment of genetic disease?

expression of gene therapy is very transient


Individuals with Acute Intermittent Porphyria should particularly avoid:



Individuals with a G6PD deficiency should particularly avoid:

anti-malarial drugs


A patient presents with neurologic abnormalities and progressive renal failure. As a child, the patient recalls experiencing pain crises accompanied by an inability to sweat and periodic episodes of heat stroke. Workup of the patient reveals an accumulation of glycosphingolipids in the skin biopsy. Which of the following is the most appropriate treatment for this patient?

enzyme replacemen


Which of the following would NOT be of concern in a patient with Beta-thalassemia major?

HbA2 production


In a 4 year old patient, which of the following should comprise over 95% of hemoglobin content in the blood?



Genetic evaluation of patient reveals one normal Beta-globin gene and one mutated Beta-globin gene. Which of the following is the MOST likely finding upon evaluation of your patient?

Low MCV (small RBCs)


Cooley's anemia can be detected by the absence of which of the following?



Which of the following is the correct pair of normal genetic variation steps that occur in meiosis?

disjunction during anaphase, recombination during prophase


What type of inversion in this? 46, XX inv(9)(p13q13)

balanced pericentric


What percentage of offspring from an individual whose genotype is i21 will be abnormal?



Genotype for male with fragile X

46, Y fra(X)(q27.3)


What is indicated by a genotype of 46, X i(Xq)?

a female with isochromosome for the long arm of


Two cells derived from two different male patients are cultured in lab and stimulated to undergo meiosis. The first cell, undergoes an error during meiosis 1, the second undergoes an error during meiosis 2. If these cells were used to fertilize genotypically normal female eggs in-vitro, what will be the possible genotypes and phenotypes of their offspring?

Cell 1: 47, XXY infertile, Cell 2: 47, XYY fertile


In the ‘two-hit’ model of maternal age effect what are considered to be the first and second hits?

diminished recombination cause by a lack of chiasmata or mislocated chiasmata, faulty segregation of chromosomes by oocytes


During adjacent 1 segregation, which of the following correctly describes the fate of homologous centromeres?

they will go to different daughter cells


You are working with genetic material in the lab, and examining cell lines from an unknown genetic origin. Upon analysis of your data you notice that chromosome 3 is duplicated in 100% of your viable cells causing them all to have unbalanced karyotypes. You also notice that you have exactly 50% of the predicted number of daughter cells based on your calculations. Which of the following is the mechanism by which this defect must have occurred in all of your cells?

alternative segregation


A normal healthy parent has a baby with the genotype 47XXY i(Xq). What is the likelihood that a second child will also have an abnormal genotype?



You do a FISH study on a child who presents with severe developmental delays and seizures. He is otherwise phenotypically normal, with normal facial features and no obvious anatomic defects. What is the most likely finding?

IDIC 15 (supernumary marker chromosome)


Besides PWS and Angelman's, 15q deletions have been associated with with disorder?



Which is the most common mechanism resulting in Angelman's syndrome?

maternal deletion of 15q11q13


What effect will supplemental growth hormone have on a child with Prader-Willi Syndrome?

increase height, alleviate excessive eating


Sleep apnea is a contraindication to the use of growth hormone in PWS patients. For this reason, treatment with growth hormone should begin:

at onset of excessive eating symptoms onset


An interstitial 15q duplication is found in a FISH study. Without knowing the patient's symptoms, what can you conclude based on the fact that the methylation tests show the duplication to be paternally derived?

patient will be phenotypically normal


A 4-year-old boy comes to your clinic for an obesity evaluation. He was born at term but his mom noticed minimal movements during pregnancy. He was very floppy when he was born, had undescended testicles and mildly unusual facial features. He had difficulty feeding as an infant but now eats anything and everything in sight without satiety. What do you suspect is his genotype?

15q11-q13 paternal deletion (detected by FISH), normal karyotype


You prescribe felodipine to a hypertensive patient. A few weeks later, the patient develops a sinus infection and drinks a glass of grapefruit juice each morning with the medication you prescribed. What is the most likely outcome regarding the drug's action?

inhibition of CYP3A metabolism making the patient hypotensive


You know that a patient has decreased levels of CYP2D6. Which of the following drugs is primarily metabolized through different pathways and will be least influenced by the reduced CYP2D6 metabolism?



You are studying pharmacogenetics and have a patient that presents to you with disabling back pain. You know from your research that the patient has increased CPY3A4 levels. Which dosage of an active drug metabolized by CYP3A4 is most appropriate for treating her pain?

higher than standard dose


Why is personalized dosing so important when prescribing warfarin?

narrow therapeutic window in individual patients with wide window in populations


Which of the following patients will need a genetic screening before being put on mercaptopurine-based chemotherapy?

acute lymphoblastic leukemia patients


Which of the following mutations to a CYP gene is most likely to result in DECREASED levels of free drug in a patient's plasma?

increased copy number


Which of the following is most correct regarding CYP2D6?

it is involved in CYP2D6


Which of the following correctly defines pharmacogenetics?

the exam of individuals of alleles and their differences


You want to prescribe rifampicin to a renal transplant patient. Why will you also need to increase his dose of cyclosporin?

rifampicin induces CYP3A to metabolize cyclosporin more quickly


Which of the following best describes the study of differences in drug resistance due to allelic variation in discrete genes affecting drug metabolism, efficacy and toxicity?



Which of the following is correct regarding DNA structure?

46XY, del (4)(p13.3) represents a terminal deletion


Which of the following is a feature of BOTH mitosis and meiosis?

DNA replication during prophase


Recombination is required for which of the following to be successful?



Paternally and maternally derived homologous chromosomes synapse along their entire length to form bivalent structures during which phase of meiosis?

prophase I


During mitosis, centromeres on paired sister chromatids segregate from each other during which phase?



A female baby is born to a 25-year-old mother. The baby weighs only 3 lbs. but was carried to full term. The baby's hands remain clenched and her hips are very narrow. A valvular heart defect was identified before she was born. Shortly after her birth, the baby experiences a number of seizures. What is the baby's most likely genotype?

46, XX der(14;18)(p12;p12)+18


A baby is born to a 40-year-old mother. The baby weighs 2lbs 7 oz. even though the pregnancy was carried to full term. You notice a cleft palate as well as two extra digits on the baby's left hand. You do a transverse CT of the baby's brain and see that there is no division between right and left lobes. You diagnose the baby with Patau syndrome. A karyotype of the baby's chromosomes will show:

trisomy 13


Which of the following mutational mechanisms is observed in the hereditary persistence of fetal hemoglobin?

heterochronic expression


What’s the most common mechanism resulting in genetic disorders?

loss of function


In Huntington's disease, what is the significance of excessive repeated sequences?

Formation of a novel property toxic protein


Duchenne muscular dystrophy occurs by which mechanism of genetic mutation?

loss of function


A young mother brings her child in for an evaluation because she suspects the baby, who is learning to walk, may have a fracture. Upon physical examination you notice that he has bluish sclera, but is otherwise normal. After discussing other possible causes of the child's fracture, you confirm that he has several broken bones and decreased bone mineral density. A genetic test comes back positive for an inherited disorder in collagen formation. Which mutational mechanism has resulted in this child's phenotype?

loss of function


You want to publish a paper on a disease caused by exposure to beryllium. Which set of individuals will be the most effective sample to use in order to support a non-genetic hypothesis?

monozygotic twins who grew up in separate families


You read an article that states the concordance rate of developing diabetes type 2 is 10 for siblings, 10 for dizygotic twins and 50 for monozygotic twins. What can you conclude from this article?

strong genetic component


Locus heterogeneity means:

variants in different genes cause the same clinical presentation


Which of the following is true of Y-linked pedigrees?

Only males are affected and all sons must have an affected father


Which of the following is an example of variable expressivity?

Two 30 year old individuals have the same single-gene disease that affects muscle tone. One must use a wheelchair and the other is able to walk


Which of the following is a characteristic of autosomal recessive traits?

Carriers do not have the phenotype


Sally has 4 siblings and is married to Joe. They have 7 children and 6 grandchildren and her parents are still living. Sally has 2 nieces and 4 nephews. How many 1st degree relatives does she have?



Joe has a disease called awesomitis, he is married to Jane and they have 4 children. Neither of his sons are affected but both of his daughters, Janet and Jenny are. His daughter Janet married Jed and they have identical twin boys who both have awesomitis and one son who is unaffected. One of the twins, Justin, marries Bieber, who is unaffected. They have 3 sons who do not have awesomitis. What is the inheritance pattern?

x linked dominant


Which of the following is true regarding gene families?

Duplication rich regions are associated with non-allelic homologous recombination


Which of the following is true regarding copy number variations?

They are often enriched with sequence gaps


Which of the following best describes pseudogenes?

They are non-functional genes that can be synthesized through reverse transcription


Alpha satellites are located _____

close to centromeres and probably function during segregation


all pertain to retrotransposone

2. insertional inactivation
3. mobility to any position on genome


You suspect a hemoglobinopathy in a patient of yours. You decide to run the diagnostic test by performing PCR of the genomic DNA surrounding exon 1 of the beta globin gene and digesting the PCR product with the restriction enzyme Mst II. Upon gel electrophoresis, you notice that the patient's DNA sample has a 1.15 kb fragment instead of the 1.35 kb fragment in the control. What diagnosis is most likely based on this observation?

sickle cell anemia


You sequence the amino acids on 3 different individuals at codon 6 of the beta chain. Respectively, they are Glu, Lys, and Val. What are the phenotypes of these individuals? Assume homozygosity for each gene.

wild type, HbC disease, sickle cell anemia


Which of the following is a true statement regarding the nature of the mutation in sickle cell anemia?

it produces a less soluble form of hemoglobin


Which of the following correctly describes the combination of tetramers that comprise Hemoglobin A?

2 a, 2 b


What is the correct order of genes in the alpha cluster on chromosome 16?



Throughout embryogenesis, expression of hemoglobin varies. Choose the correct group of hemoglobins that are expressed at the time of birth.

alpha, beta, gamma, and delta


HbA is the major form of hemoglobin (97% of total). What combination of tetramers makes up the minor form of adult hemoglobin?

2 alpha 2 delta


A man with heterozygous alpha-thalassemia from Southeast Asia marries a woman with homozygous alpha-thalassemia from Africa. Assuming no de novo mutations occur during development, what is the likelihood that the fetus will be viable?



An 8 year old patient presents for genetic testing after experiencing a pain crisis on a recent trip to Europe with her family. A positive test for which of the following would help you diagnose this patient with sickle cell disease?

protein electrophoresis


A young patient is brought to clinic due to excessive eating, weight gain and intellectual disability. Which of the following is the most appropriate test in guiding your diagnosis of the suspected condition?

FISH for deletions of chromosome region 22q11


You are studying a new genetic disease that has been shown to have 100% penetrance among allele carriers. When you calculate the odds ratio of having the allele, you get an estimate of 1.0015. What can you conclude about the population attributable risk of getting this disease for those who have the genetic variant?

high because penetrance is 100%


Why does population stratification often lead to false positive findings in genetic association studies?

ethnic categories are often the product of two more ancient populations so controls may have 2 different allele frequencies but are counted as genetically similar


Which of the following is correct regarding candidate association studies?

association suggests linkage disequilibrium with a causal mutation


Which markers are typically used in genetic linkage studies?



What is true about functional and positional cloning?

functional cloning uses known biology to determine gene based on function


What is the most limiting factor of gene association studies?

multiple testing correction must include results of all studies, even those that have never been published


Genetic linkage studies assume that:

multiplex families (families with multiple cases of a disease) share genome segments that are disproportionately co-inherited


Copy number mutations

are typically detected by local SNP patterns


What percentage of babies with Down syndrome also have congenital heart defects?



If a pregnant 40-year-old woman presents to your office at 16 weeks of gestation, what standard test are you likely to perform to rule out Down syndrome?

amniocentesis followed by FISH


About 95% of Down syndrome is due to true trisomy 21. Which of the following karyotypes could also be Down syndrome?

47 XX, +21/46 XX


What are the 3 steps of sexual determination?

genetic presence or absence of Y, development of gonads, development of internal and external organs


An individual with the karyotype 46XY has a duplication of the DAX1 gene and normal levels of SRY. What will be the outcome of sexual development in the embryo?

development of ovaries and testes


A 46XY individual with androgen insensitivity will have:

external female genitalia with male gonads


What is the purpose of a whole chromosome paint using FISH?

identification of markers and translocations


The genotype t(15;17) is diagnostic for which type of leukemia?

acute promyelocytic (APL


The bcr-abl oncogene is detected by FISH using which type of probe?



In which of the following cases would you use a centromeric probe during FISH analysis?

eneumeration leukemia


Hyperdiploidy revealed by chromosome and FISH analysis is diagnostic for which type of leukemia?

acute lymphoblastic (ALL)


An 11-year-old female presents to your office with excessive bleeding after a tooth extraction. Upon microscopy you find 15% blasts. You decide to examine a bone marrow sample, which shows Auer Rods and 81% blasts. A FISH analysis using a fusion probe detects a PML/RARA translocation. What is your diagnosis?

AML acute myelogenous leukemia


After ordering a Chromosomal Microarray report on a patient, how many oligomers should be present before pursuing further investigation?



Which of the following is an essential characteristic for normal epigenetic marking to be successful?

modification remain stable after fertilization


Which of the following correctly describes the mechanism for an epigenetic modification?

reversible modification to chromatin structure


Prader-Willi and Angelman's syndromes result from genetic aberrations to the same region of chromosome 15. Which of the following correctly explains why the resulting phenotypes differ from each other?

Phenotype depends on whether the mutation is maternal or paternal in origin


Methyl CpG binding proteins are the proteins that bind to the methylated portion of the chromosome and affect gene expression. In a patient with Prader-Willi Syndrome, where would you expect these proteins to bind?

Maternal chromosome 15, silencing transcription


How are imprinting patterns maintained in offspring?

maintenance methylation


A young child presents to your office with a genotype of 46XY del(15)(q11q13) on the maternal chromosome. Which of the following clinical features would be most consistent with the patient's genotype?

Presenting symptoms of Angelman's include mental impairments, seizures, ataxia and inappropriate laughter


Which of the following trinucleotide repeat disorders has an autosomal recessive inheritance pattern?

friedreich's ataxia


Which of the following is a suitable diagnostic procedure to determine the genotype of an individual at risk for Fragile X?

PCR with Southern blot of FMR1 to determine repeat size


Which of the following is a characteristic of Myotonic Dystrophy type 1?

expanded CTG repeats at the 3' UTR


Where do most mutations for FXTAS (Fragile X-Associated Tremor/Ataxia Syndrome) occur?

5' UTR


A deaf couple comes to your office for a consult about having a child. They are both deaf due to nonsyndromic GJB2 mutations. What is the risk of their child also being deaf?



In an attempt to diagnose a patient, you run HexA and HexB enzyme assays. You observe that both HexA and HexB activity is reduced. Which diagnosis is most consistent with this finding?

sandhoff disease


Why is it important to treat a PKU woman with a low phenylalanine diet during pregnancy?

high Phe in maternal blood can damage fetal CNS regardless of the baby's genotype


Which of the following genotypes with alpha1 anti-trypsin deficiency will have the highest levels of elastase?



PKU is an autosomal recessive disorder with high allelic heterogeneity. Thus, most PKU patients are genotypically

compound heterozygotes


A six month old baby comes to your office for a routine checkup. During the head and neck exam, you notice a cherry-red spot in the baby's eye. You suspect which of the following genetic disorders?

tay sachs