Holt-Oram Syndrome: A Rare Variant

Abstract

Holt-Oram syndrome is an autosomal dominant disorder, characterised by skeletal abnormalities of the upper limb associated with congenital heart defect, mainly atrial and ventricular septal defects. Skeletal defects exclusively affect the upper limbs in the preaxial radial ray distribution and are bilateral and asymmetrical. They range from clinodactyly, absent or digitalised thumb, hypoplastic or absent radii, and first metacarpal to hypoplastic ulna and carpal bone anomalies. Cardiac involvement ranges from asymptomatic conduction disturbances to multiple structural defects. Structural defects are seen in 75% of the cases and include both atrial and ventricular septal defect. More complex cardiac lesions such as Tetrology of Fallot, endocardial cushion defects, double outlet right ventricle, and total anomalous pulmonary venous return are observed uncommonly. An aneurysm of the interatrium septum is an infrequent finding in infants. It has been speculated that atrial septal aneurysm (ASA) is a direct source of thrombus formation. Paradoxical embolism of venous thrombi across a right to left shunt is possibly responsible for the cryptogenic stroke in a patient with ASA. However, coagulopathy associated with cyanotic congenital heart defect may also be contributory. Our patient had a rare association of complex cardiac lesion (tricuspid atresia, pulmonary stenosis, atrial septal aneurysm) with cardiac conductive defects and left parietal infarct along with the usual skeletal abnormalities.