GEN-ARMGeneticsReviewExaminationforNursesinObstetrics

55. Viruses like Rubella can cause syndromes or single birth defects, but they must be present during the period of embryogenesis (1 ½ to 8 weeks after conception). 56-58. The twins are different sexes and must be dizygous, with 50% of their genes in common like siblings. When twins share an anomaly, they are concordant (answer 3.6-B). ................
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