Clinical scenario: repeated chest infection / murmur/ hypoplastic thumb
A 7-year-old girl is evaluated for poor exercise tolerance and recurrent respiratory tract infections. On examination, she has a wide, fixed splitting of the second heart sound and a grade 2/6 ejection systolic murmur best heard at the left upper sternal border. Her right thumb is hypoplastic, and the thenar eminence is underdeveloped. There is no cyanosis or clubbing. Chest radiography shows mild cardiomegaly with increased pulmonary vascular markings.
Which of the following congenital heart defects is most likely associated with this syndrome?
A. Atrial septal defect
B. Coarctation of the aorta
C. Patent ductus arteriosus
D. Tetralogy of Fallot
E. Ventricular septal defect
Correct answer & Explanation:
Correct Answer: A. Atrial septal defect
Explanation: ASD / Holt-oram syndrome
This child has features of Holt–Oram syndrome (heart–hand syndrome), an autosomal dominant disorder caused by mutations in the TBX5 gene.
Characteristic findings include:
- Upper limb abnormalities, particularly involving the thumb and radial ray
- Hypoplastic or absent thumb
- Thenar hypoplasia
- Congenital heart defects, most commonly:
- Secundum atrial septal defect (most common)
- Ventricular septal defect
- Cardiac conduction abnormalities may also occur.
The clinical findings of fixed splitting of S2 and a pulmonary flow murmur are classic for an atrial septal defect.
