Which condition is referred to as Trisomy B in some contexts?

Which condition is referred to as Trisomy B in some contexts?

• A. Trisomy 13 (Patau)
• B. Trisomy 21 (Down)
• C. Trisomy 18 (Edwards)
• D. Trisomy B (Patau)

Answer: (D)

Different naming conventions in cytogenetics can map the same condition to different labels. In some older sources, Trisomy B has been used to refer to Patau syndrome, which is caused by an extra chromosome 13 (Trisomy 13). So the label Trisomy B points to Patau syndrome. The other well-known trisomies—Down syndrome from Trisomy 21 and Edwards syndrome from Trisomy 18—are not referred to as Trisomy B in those contexts. Modern terminology usually uses Trisomy 13 for Patau syndrome.

Different naming conventions in cytogenetics can map the same condition to different labels. In some older sources, Trisomy B has been used to refer to Patau syndrome, which is caused by an extra chromosome 13 (Trisomy 13). So the label Trisomy B points to Patau syndrome. The other well-known trisomies—Down syndrome from Trisomy 21 and Edwards syndrome from Trisomy 18—are not referred to as Trisomy B in those contexts. Modern terminology usually uses Trisomy 13 for Patau syndrome.