Which congenital anomaly is least commonly associated with other congenital abnormalities?

Which congenital anomaly is least commonly associated with other congenital abnormalities?

• A. Tracheoesophageal fistula
• B. Meningomyelocele
• C. Omphalocele
• D. Gastroschisis

Answer: (D)

Gastroschisis is usually an isolated abdominal wall defect, meaning the fetus’ other organ systems are typically normal. This isolated nature stems from its likely vascular disruption/closing defect mechanism rather than a broad developmental syndrome. Because it often occurs without additional system-wide anomalies, gastroschisis has the lowest rate of associated congenital abnormalities among these options. In contrast, omphalocele frequently coexists with other anomalies and chromosomal disorders (such as cardiac defects or Beckwith-Wiedemann syndrome), so it is commonly associated with multiple abnormalities. Tracheoesophageal fistula often appears as part of broader associations like VACTERL, where several organ systems are affected. Meningomyelocele, a neural tube defect, is frequently accompanied by other defects and conditions (hydrocephalus, Chiari II malformations, etc.).

Gastroschisis is usually an isolated abdominal wall defect, meaning the fetus’ other organ systems are typically normal. This isolated nature stems from its likely vascular disruption/closing defect mechanism rather than a broad developmental syndrome. Because it often occurs without additional system-wide anomalies, gastroschisis has the lowest rate of associated congenital abnormalities among these options.

In contrast, omphalocele frequently coexists with other anomalies and chromosomal disorders (such as cardiac defects or Beckwith-Wiedemann syndrome), so it is commonly associated with multiple abnormalities. Tracheoesophageal fistula often appears as part of broader associations like VACTERL, where several organ systems are affected. Meningomyelocele, a neural tube defect, is frequently accompanied by other defects and conditions (hydrocephalus, Chiari II malformations, etc.).