Variation in severity of cardiac disease in Holt-Oram syndrome.

We describe a family with Holt-Oram syndrome (HOS) with variable hand and cardiac manifestations. One affected relative had complex congenital malformations of the heart consisting of an endocardial cushion defect and hypoplasia of the left ventricle. The literature from 1974 to 1995 is reviewed. Atrial septal defect is the most cardiac abnormality (60.3% of 189 cases) occurring singly or in combination with other malformations. Thirty-three individuals (17.5%) of literature cases) have more complex congenital malformations of the heart requiring complicated medical management and extensive cardiac surgery. Many genetic reference sources of HOS indicate that single or less severe cardiac malformations are expected in this disorder. It is important to provide more information about the occurrence and spectrum of severity of malformations of the heart to individuals and families where HOS is present.