ABGC Practice Questions and Answers 2024 Updated

ABGC Practice Questions and Answers 2024 Updated Under what circumstances should an infant with clinical features of Down syndrome be karyotyped? A. Only if the parents desire more children B. Only if the mother is younger than 35 years old C. Only if not all of the features of Down syndrome are present D. Only if the mother has had 3 early miscarriages E. Always - CORRECT ANSWER-E. Always What is the parental origin and stage of meiosis when most meiotic errors occur resulting in chromosomal trisomy? A. Maternal meiosis I B. Paternal meiosis I C. Maternal meiosis II D. Paternal meiosis II E. Maternal meiosis I and II are equally likely - CORRECT ANSWER-A. Maternal meiosis I A 23-year-old woman has a baby with the karyotype 47,XY,+21. Which of the following is the correct conclusion? A. This woman's risk for having another baby with a chromosome abnormality is the same as other women her age B. Either the woman or her husband probably has a Robertsonian translocation C. Either the woman or her husband probably has germ line mosaicism D. Either the woman or her husband probably carriers a balanced reciprocal translocation E. Both members of the couple probably have normal chromosomes - CORRECT ANSWER-E. Both members of the couple probably have normal chromosomes Which of the following cytogenetic results listed below indicate that the child in question has Down syndrome? A. 47,XX,+22 B. 46,XY,t(2;21)(q13;q21)pat C. 46,XY,+21,der(21;22)(q10;q10) D. 45,XX,der(14;21)(q10;q10)mat E. 46,XX.ish del(21)(q22.3q22.3)(D21S65-) - CORRECT ANSWER-C. 46,XY,+21,der(21;22)(q10;q10) T/F The karyotype of a spontaneous abortion is more likely to be abnormal than that of a stillborn infant. - CORRECT ANSWER-True T/F The most common Down syndrome karyotype involves a Robertsonian translocation between chromosomes 14 and 21 - CORRECT ANSWER-False T/F It is possible to have the Down syndrome phenotype and have 46 chromosomes. - CORRECT ANSWER-True T/F Most of the mothers of babies with Down syndrome are over 35 years of age. - CORRECT ANSWER-False An individual with 45 chromosomes and a Robertsonian translocation between both copies of chromosome 21 can have live born children with a normal karyotype or with trisomy 21. - CORRECT ANSWER-False Which of the following karyotypes, if observed in an embryo, is least likely to survive to birth? A. 45,X B. 47,XX,+16 C. 47,XX,+21 D. 47,XX,+18 E. mos 47,XXX/46,XX - CORRECT ANSWER-B. 47,XX,+16 Which of the following chromosome abnormalities occurs only during meiosis II? A. 45,X B. 47,XXX C. 47,XXY D. 47,XYY E. mos 45,X/46,XX - CORRECT ANSWER-D. 47,XY