ABGC Boards Overview Study Guide Exam Questions and Answers

ABGC Boards Overview Study Guide Exam Questions and Answers Angelman Syndrome causes (expression and % of total) - CORRECT ANSWER- **paternal imprinting defect, should be maternal expression 5-7 kb deletion on maternal chr15q11.2-13 (60-70%) UBE3A maternal deletion (11%) Paternal UPD15 (3-7%) Angelman testing strategy and condition features - CORRECT ANSWER-methylation first since finds ~80% of cases then UBE3A seq and del/dup features: happy demeanor, abnormal gait, seizures, delayed/absent speech Prader-Willi Syndrome causes (expression and % of total) - CORRECT ANSWER- **maternal imprinting defect, should be paternal expression of region 5-6 kb deletion on paternal chr15q11.2-13 (60-70%) Deletion involves SNRPN gene Maternal UPD15 (20-30%) PWS testing strategy and condition features - CORRECT ANSWER-Methylation will detect 99% Features: hypotonia, FTT, obesity, hyperphagia, small hands and feet, DD Angelman and Prader-Willi pneumonic devices - CORRECT ANSWER-Moms are Angels = should have maternal expression of the region therefore PWS is in a region that typically has paternal expression Beckwith-Wiedemann syndrome causes (imprinting and % breakdown) - CORRECT ANSWER-**paternal imprinting, maternally expressed Sporadic (85%) Loss of methylation on maternal chr11p15.5 IC2 (50%) Paternal UPD11 (7-10%) Gain of methylation on maternal chr11p15.5 IC1 (5%) Maternal CDKN1C deletion (40% w/ family hx, 5% w/o) also KCNQ1 gene Beckwith-Wiedemann syndrome testing strategy and condition features - CORRECT ANSWER-Order methylation first, then CDKN1C sequencing and del/dup