Karyotyping of products of conception from a woman with recurrent first trimester miscarriage demonstrates an autosomal trisomy. Which autosome is most frequently involved in chromosomally abnormal spontaneous abortions?

• A Trisomy 21
• B Trisomy 18
• C Trisomy 13
• D Trisomy 16 ✓

Explanation

Trisomy 16 is the single most common autosomal trisomy in spontaneous abortuses, accounting for roughly a third of trisomic losses, and it is virtually always lethal so it is almost never seen in liveborn infants. Trisomies 21, 18 and 13 are the classic viable autosomal trisomies seen at birth, which makes them tempting but incorrect distractors here. Roughly half of all first trimester miscarriages overall are chromosomally abnormal, with autosomal trisomy being the largest category.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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