A Rare Variant and Unusual Presentation of Holt Oram Syndrome in a Child.

Holt Oram syndrome is a rare genetically inherited disorder characterized by various skeletal abnormalities of the upper limb with an underlying structural heart defect. Family history and conduction defects may or may not be there. The diagnosis is often clinical; if the criteria are not fulfilled, then genetic studies may be required. This syndrome can also occur with complex congenital heart defects, heart blocks, and arrhythmias. The correlation between the severity of cardiac and skeletal manifestations was not studied, and in severe conditions and acute presentation, the patient may have atrial, supraventricular, and ventricular fibrillation. The association of radius with hand deformity and the cardiac defect is well reported, but this disease's involvement of the humerus and Supraventricular tachycardia (SVT) is rare. Here, we are reporting a case of Holt Oram syndrome in a five-year male child with unusual skeletal hypoplastic humerus who presented with breathlessness, palpitations, and supraventricular tachycardia and suffered a total of three episodes which were managed with adenosine and cardioversion successfully. The involvement of the humerus, along with symmetrical bilateral radial defect with Atrial septal defect (ASD) and Supraventricular tachycardia (SVT), is a unique feature of Holt Oram syndrome seen in our case.