Chromosomal Diseases

(M1.BC.15.73) A 36-year-old pregnant woman undergoes a routine first-trimester pregnancy screen, which demonstrates decreased free B-hCG and decreased PAPP-A. Additionally, ultrasound shows increased nuchal translucency. A presumptive diagnosis is made based upon these findings and is later confirmed with genetic testing. The mother decides to carry the child to term, and, at birth, the child is noted to have cleft palate and polydactyly. The child is most likely to have which of the following karyotypes?

(M1.BC.15.72) A 39-year-old pregnant woman at 16 weeks gestation recently underwent a quad-screen which revealed elevated beta-hCG, elevated inhibin A, decreased alpha-fetoprotein, and decreased estradiol. An ultrasound was performed which found increased nuchal translucency. Which of the following is recommended for diagnosis?

(M1.BC.15.73) A 36-year-old G1P1 woman with no previous prenatal care or screening delivers a baby boy at 39 weeks gestation. On exam, you note micrognathia, microphthalmia, malformed low-set ears, rocker-bottom feet, and clenched hands with overlapping fingers. Which of the following karyotypes would you expect to find in this patient?

(M1.BC.15.72) You are called to evaluate a newborn. The patient was born yesterday to a 39-year-old mother. You observe the findings illustrated in Figures A-C. What is the most likely mechanism responsible for these findings?

(M1.BC.15.72) A 37-year-old woman presents for prenatal counseling at 18 weeks gestation. The patient tells you that her sister recently had a child with Down's syndrome, and the patient would like prenatal screening for Down's in her current pregnancy.

Which of the following prenatal screening tests and results would raise concern for Down's syndrome?

(M1.BC.15.72) You are called to examine a one-hour-old baby who was born with a facial defect illustrated in Figure A. The patient's ears appear to be low-set. On auscultation, there is a holosystolic murmur along the lower left sternal border. Basic labs return notable for hypocalcemia. What is the most likely underlying mechanism responsible for the abnormalities seen in this newborn?

(M1.BC.14.27) A 41-year-old Caucasian female gives birth to a male infant at 38 weeks of gestation. On physical exam, the infant has a small jaw, malformed, low set ears, clenched hands with overlapping fingers, a prominent occiput, and a foot abnormality (Figure A). Which of the following is the etiology of this presentation?

(M1.BC.14.1) A 39-year-old Caucasian female gives birth to a male child with the following physical characteristics: epicanthal folds, flat facial profile, a protruding tongue, and a characteristic finding on the palm (Figure A). Which of the following cardiovascular defect(s) is/are associated with the above presentation?

(M1.BC.14.0) A 28-year-old G2P1 female is concerned that she may give birth to another child with Down syndrome. She states that she may not be able to take care of another child with this disorder. Which of the following tests can confirm the diagnosis of Down syndrome in utero?

(M1.BC.14.0) A 40-year-old G1P0 returns to her gynecologist for an amniocentesis after an abnormal quad screen. A chromosomal analysis demonstrated the following karyotype (Figure A). Which of the following syndromes does the fetus have?

(M1.BC.14.7) A 41-year-old G2P1 woman who is 15 weeks pregnant visits her OB-GYN for a routine prenatal quad screen. The results show decreased serum alpha fetal protein (AFP) and estriol, and increased serum beta human chorionic gonadotropin (hCG) and inhibin A. Subsequent ultrasound demonstrates increased nuchal translucency. The physician performs an amniocentesis to confirm these positive findings. Which of the following karyotypes is to be expected if the amniocentesis confirms the result of the quad screen?