2023年遗传学试卷(最新版)最全面精品资料Chromosomal disorder.pdf
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 trimester 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 of 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 peripheral 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 analyses 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 syndrome C.The father is to blame for their daughters condition D.There is no increased risk for having a child with Down syndrome with future pregnancies E.There is a 1%recurrence risk with each pregnancy 2.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 karyotype of this child?(5.0)P74 A.X,X B.X,Y C.X,O D.XXY E.XXX 3.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 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.Skin 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 of the aortic root diameter by echocardiography D.Test icularbiopsy E.Test osteronelevel 4.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 of chromosomes is:(5.0分)A.endoreduplicated B.diploid C.endoreduplicated D.tetraploid 7.Which of the following could produce an XY female?(5.0分)A.Point mutationin the Sry gene B.Deletion of the Sry gene C.Translocation of the Sry gene to the X chromosome during meiosis in the father D.All of the above 8.Which of the following is not true of Fragile X syndrome?(5.0 分)A.It can be diagnosed using a karyotype B.It is associated with methylation C.It is caused by a trinucleotide repeat expansion D.It displays nearly 100%penetrance （与 CGG重复次数有关）9.Each of the following chromosome abnormalities involves a 20 megabase region of the long arm of chromosome 5(5q).Which abnormality is most likely to cause severe disease?(5.0 分)A.Duplication of the region B.Deletion of the region C.A balanced translocation involving the region(i.e.,in the translocation carrier)D.Pericentricinversion 10.If an eneuploid with a karyotype that is 2N+1 has 9 chromosomes,what is the normal haploid number of this species?(5.0分)A.10 B.9 C.8 D.5 E.4 11.Which of the following techniques was mostly used to detect a trisomy?(5.0分)A.Southernblotting B.RFLP C.FISH D.PCR-SSCP 12.Which of the following chromosomal aberrations can be of either sex:(5.0分)A.XXY B.XYY C.trisomy 21 D.monosomic X 13.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 examination revealed a Tanner I female with mild pterygium colli,widely spaced nipples,and cubitus valgus bilaterally.Height is 58 inches(5th percentile).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 Turner syndrome B.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 male D.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 short 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(5th percentile).Diagnosis will be most definitively confirmed by:(5.0分)A.Buccalsmear B.Growthhormone stimulation testing C.Chromosome analysis of peripheral blood lymphocytes D.Pelvicultrasonography E.Serumestrogen level 15.Color blindness is more likely to occur in males than females because(5.0分)A.Males have an tendency to deposit cholesterol in small blood vessels thereby reducing the oxygen and food supply to the retina B.Genes for the characteristic are located in sex chromosomes C.The trait is dominant in males and recessive in females D.Males requiremore vitamin A to achieve the same sensitivity in the rods and cones of the retina E.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 feeding 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 she 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 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 syndrome B.FragileX syndrome 头大、舌大、耳大、智力障碍 C.Prader-Willi syndrome D.Beckwith-Wiedemann syndrome E.Angelmansyndrome 癫痫和抽搐 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,XY B.45,XO C.47,XXY D.Defect on chromosome 15 E.Defect onchromosome 5 cri du chat F.Trisomy 21 18.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 foroccasions in the third trimester during which the mother felt the baby kickedless frequently.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 ocular 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 lymphocytes revealed a 46,XX,t(15q;21q)karyotype.You should now advise the parents that:(5.0分)A.A chromosomeanalysis should be performed upon both parents B.The recurrencerisk for Down syndrome with future pregnancies is approximately 1%C.Their daughterdoes not have Down syndrome,since she does not have 47 chromosomes D.Their recurrence riskfor Down syndrome is solely related to maternal age at the time of delivery E.This is a normal variant 19.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)at 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,tongue thrusting,short fifthfingers bilaterally,and a single palmar flexion crease on the left.Muscletone was moderately(5.0分)A.Advise that achromosome analysis is unnecessary,since she was not 35-years-old or above atthe time of delivery B.Counsel theparents concerning the autosomal recessive inheritance pattern of their childscondition C.Order achromosome analysis of peripheral blood lymphocytes D.Order a serumcreatinine kinase and electromyogram and consider a muscle biopsy pendingresults E.Recommend acranial MRI 20.You are called to see a newborn in the delivery room.The nurse tells you that the child looks dysmorphic.On physical exam,you note that the child has upward-slanting eyes,a small upturned nose with a saddle bridge,inner epicanthal folds,small ears,simian creases,and clinodactyly of both fifth fingers.The child appears to have floppy tone as well.These findings are typical for:(5.0分)（孩子的眼睛向上倾斜，小小的朝天鼻与鞍桥，内眦褶，小耳朵，猴折痕，两只手的第五根手指弯曲。这孩子似乎有软盘的色调为好）A.Trisomy 21 B.Trisomy 13 C.Trisomy 18 D.Turner syndrome E.Klinefeltersyndrome
