Which syndrome (Trisomy 13) is characterized by severe anomalies with about 90% having cardiac defects and a poor prognosis?

• A. Patau syndrome
• B. Trisomy 21
• C. Turner syndrome
• D. Edwards syndrome

Answer: (A)

Patau syndrome, which is trisomy 13, is characterized by widespread, severe congenital anomalies. A hallmark of this condition is the very high prevalence of major heart defects—about 90% of affected fetuses or newborns have congenital heart disease—along with a overall poor prognosis and limited survival. This combination of severe multisystem abnormalities and near-ubiquitous cardiac involvement is what makes Patau syndrome the best match for the description. By contrast, Down syndrome (trisomy 21) tends to have milder features and better outcomes, Turner syndrome is not a trisomy, and Edwards syndrome (trisomy 18) also has a grave prognosis but with a different spectrum of findings; the description given specifically aligns with trisomy 13.