We report on a case of a 60-year-old man with progressive heart failure, mitral and aortic valve insufficiency and bilateral asymmetrical skeletal upper-limb deformities. Central to the suspicion of Holt-Oram syndrome in this patient was the surgical finding of agenesis of the left pericardium. A Holt-Oram syndrome diagnostic was confirmed through molecular analysis of the TBX5 gene. A new amino acid substitution at position 61 of the TBX5 gene was identified and confirmed the clinical diagnosis of Holt-Oram syndrome. The clinical presentation of the present case broadens the clinical spectrum of Holt-Oram syndrome and point out the importance of Tbx 5 in pericardium development. It is still an unstudied issue whether TBX5 mutations may also be present in other clinical presentations where absence of the pericardium is a feature.