遗传学试题资料：Chromosomal disorder

1、1.A 2-month-old Caucasian female infant is seen for a well baby visit. The mother is concerned that the child is floppy, but is uncertain, since this is her first child. Birth weight was 7 pounds 2ounces at term. Prenatal and perinatal histories are unremarkable except for occasions in the third tri

2、mester during which the mother felt the baby kickedless frequently. The mother was 30 years old at the time of delivery. Prior medical history revealed almost continual nasal congestion. Physical examination revealed normal vital signs and growth parameters. Findings included a slight upward slant o

3、f the palpebral fissures, extra folds of skin at the inner ocular canthi, small ears, tongue thrusting, short fifth fingers bilaterally, and a single palmar flexion crease on the left. Muscle tone was moderately decreased throughout, with a pronounced head lag. Chromosome an alysis performed upon pe

4、ripheral blood lymphocytes revealed a 46, XX,t(15q;21q) karyotype. The results of chromosome analyses performed(5.0)（结果包括微微向上倾斜的睑裂，额外的褶皱的皮肤的内眼眦，小耳朵，舌头冲断，短的第五个手指两侧，和一个单一的掌褶纹的左边。肌肉是适度降低整个头部，具有明显的滞后。）A.Amniocentesis is indicated for future pregnancies, as well as peripheral blood leukocyte chromosome a

5、nalyses for all of the fathers first degree relatives（羊膜穿刺术是用于未来的怀孕，以及所有的父亲的一级亲属外周血白细胞染色体分析）B.The father has a mild form of Down syndromeC.The father is to blame for their daughters conditionD.There is no increased risk for having a child with Down syndrome with future pregnanciesE.There is a 1%recu

6、rrence risk with each pregnancy2.A 14-year old girl is brought to you with lack of menarche. Physical examination finds normal breast development but the vagina ends in a blind pouch and there is no palpable uterus. Serumtestosterone is in the male range and LH is elevated. What is the most likely k

7、aryotype of this child?(5.0) P74A.X,XB.X,YC.X,OD.XXYE.XXX3.A 15-year-old Caucasian male child is seen in the office due to the onset of bilateral nontender breast enlargement 2 months ago. He is doing well in school academically and is a member of the varsity basketball team. He shaves only once per

8、 week and has not yet noted a deepening of his voice. He has been healthy to this point, and there is no family history of similar symptoms. Physical examination revealed normal vital signs. Height is 6feet 1 inch. The upper lower segment ratio was 0.75 (decreased), and the arm span was 76 inches. S

9、kin was fair. There was scant facial, axillary, and pubichair. Breasts were Tanner Stage II, and genitalia were Tanner Stage I.The evaluation most likely to yield the definitive diagnosis is:(5.0)A.Chromosome analys is of peripheral blood lymphocytes 外周淋巴血细胞的染色体分析B.Estrogen level雌激素水平C.Measurement o

10、f the aortic root diameter by echocardiographyD.Test icularbiopsyE.Test osteronelevel4.近端着丝粒染色体之间通过着丝粒融合而形成的易位称为（）。(5.0分)A.单方易位B.串联易位C.罗伯逊易位D.不平衡易位E.复杂易位5.非整倍体的形成原因可以是（）。(5.0分)A.双雌受精B.双雄受精C.核内复制D.染色体不分离E.核内有丝分裂6.A cytogenetic term that refers to a mitotic cell that contains twice the normal number o

11、f chromosomes is:(5.0分)A.endoreduplicatedB.diploidC.endoreduplicatedD.tetraploid7.Which of the following could produce an XY female?(5.0分)A.Point mutationin the Sry geneB.Deletion of the Sry geneC.Translocation of the Sry gene to the X chromosome during meiosis in the fatherD.All of the above8.Which

12、 of the following isnottrue of Fragile X syndrome?(5.0分)A.It can be diagnosed using a karyotypeB.It is associated with methylationC.It is caused by a trinucleotide repeat expansionD.It displays nearly 100% penetrance （与CGG重复次数有关）9.Each of the following chromosome abnormalities involves a 20 megabase

13、 region of the long arm of chromosome 5(5q). Which abnormality is mostlikely to cause severe disease?(5.0分)A.Duplication of the regionB.Deletion of the regionC.A balanced translocation involving the region (i.e., in the translocation carrier)D.Pericentricinversion10.If an eneuploid with a karyotype

14、that is 2N+1 has 9 chromosomes, what is the normal haploid number of this species?(5.0分)A.10B.9C.8D.5E.411.Which of the followingtechniques was mostly used to detect a trisomy?(5.0分)A.SouthernblottingB.RFLPC.FISHD.PCR-SSCP12.Which of the following chromosomal aberrations can be of either sex:(5.0分)A

15、.XXYB.XYYC.trisomy 21D.monosomic X13.You are asked to evaluate a 15-year-old adolescent girl for primary amenorrhea. She has been healthy but has had long-standing short stature. No breast budding was reported. Her mother experienced menarche at age 11 years and has had regular menses. Physical exam

16、ination revealed a Tanner I female with mild pterygium colli, widely spaced nipples, and cubitus valgus bilaterally. Height is 58 inches (5thpercentile). Chromosome analysis of peripheral blood lymphocytes revealed a 45, X karyotype. You would advise the patient that she is a:(5.0分)A.Carrier of Turn

17、er syndromeB.Candidate forestrogen replacement therapy可以用雌激素治疗，第二性征得到体现，但仍旧不育C.Genetic maleD.Postmenopausal female （绝经后女性）E.Trueher maphrodite 14. You are asked to evaluate a 15-year-old adolescentgirl for primary amenorrhea in the adolescent clinic. She has been healthy but has had long-standing sh

18、ort stature. No breast budding was reported. Her motherexperienced menarche at age 11 years and has had regular menses. Physicalexamination revealed a Tanner I female with mild pterygium colli, widely spacednipples, and cubitus valgus bilaterally. Height is 58 inches (5thpercentile). Diagnosis will

19、be most definitively confirmed by:(5.0分)A.BuccalsmearB.Growthhormone stimulation testingC.Chromosome analysis of peripheral blood lymphocytesD.PelvicultrasonographyE.Serumestrogen level15.Color blindness is more likely to occur in males than females because(5.0分)A.Males have an tendency to deposit c

20、holesterol in small blood vessels thereby reducing the oxygen and food supply to the retinaB.Genes for the characteristic are located in sex chromosomesC.The trait is dominant in males and recessive in femalesD.Males requiremore vitamin A to achieve the same sensitivity in the rods and cones of the

21、retinaE.Some males have difficulty absorbing vitamin A, a necessary prerequisite to the synthesis of visual purple (rhodopsin)16. A 7-year-old girl is seen in the clinic with developmental delay, behavioral problems and obesity. Upon questioning, it is learned that as an infant, she had trouble feed

22、ing and was assisted with special techniques, and that she was also very hypotonic. This improved with age, andaround 36 months, she rapidly began to gain weight. She exhibits food- seeking behavior, and has been known to raid the kitchen in the middle of the night. Her appetite is excessive, and sh

23、e never seems to be satiated. She has tempertantrums and is manipulative when it comes to food issues. Physically, she has a narrow forehead, a down-turned mouth, and small hands and feet for her height. Family history is negative for similar symptoms. High-resolution chromosome analysis is ordered

24、and although 46 chromosomes are present, thereis a small deletion in the long arm of chromosome 15. The most probable diagnosis for this child is which of the following?(5.0分)A.Sotos syndromeB.FragileX syndrome 头大、舌大、耳大、智力障碍C.Prader-Willi syndromeD.Beckwith-Wiedemann syndromeE.Angelmansyndrome 癫痫和抽搐

25、 呆笑 不说话17.In your pediatric clinic, you see an 8-year-old white, boy, who is brought to you by his parents, who barely speak any P74(5.0分)A.Normal 46,XYB.45,XOC.47,XXYD.Defect on chromosome 15E.Defect onchromosome 5 cri du chatF.Trisomy 2118.A 2-month-old Caucasian female infant is seen for a well b

26、aby visit. The mother is concerned that the child is floppy, but is uncertain, since this is her first child. Birth weight was 7 pounds 2ounces at term. Prenatal and perinatal histories are unremarkable except foroccasions in the third trimester during which the mother felt the baby kickedless frequ

27、ently. The mother was 30 years old at the time of delivery. Priormedical history revealed almost continual nasal congestion. Physical examination revealed normal vital signs and growth parameters. Findingsincluded a slight upward slant of the palpebral fissures, extra folds of skinat the inner ocula

28、r canthi, small ears, tongue thrusting, short fifth fingersbilaterally, and a single palmar flexion crease on the left. Muscle tone wasmoderately decreased throughout, with a pronounced head lag. Chromosomeanalysis performed upon peripheral blood lymphocytesrevealed a 46, XX,t(15q;21q) karyotype.You

29、 should now advise theparentsthat:(5.0分)A.A chromosomeanalysis should be performed upon both parentsB.The recurrencerisk for Down syndrome with future pregnancies is approximately 1%C.Their daughterdoes not have Down syndrome, since she does not have 47chromosomesD.Theirrecurrence riskfor Down syndr

30、ome is solely related to maternal age at the time of deliveryE.This is a normalvariant19.A 2-month-old Caucasian female infant isseen for a well baby visit. The mother is concerned that the child is floppy,but is uncertain, since this is her first child. Birth weight was 7 pounds 2ounces (3.24 kg) a

31、t term. Prenatal and perinatal histories are unremarkableexcept for occasions in the third trimester during which the mother felt thebaby kicked less frequently. The mother was 30 years old at the time ofdelivery. Prior medical history revealed almost continual nasal congestion.Physical examination revealed normal vital signs and growth parameters.Findings included a slight upward slant of the palpebral fissures, extra foldsof skin at the inner ocular canthi, small ears,