Holt-Oram syndrome (HOS)

HOS occurs in one of every 100,000 births. The mutation can be spontaneous or hereditary.It is the most common form of what is known as heart-hand syndrome due to malformations of the radius and the thumb, as well as of the heart. The corresponding section of the gene is on chromosome 21. Congenital heart defects are present in 70 per cent of cases, with ventricular and atrial septal defects, constrictions in the area of the aortic arch and cardiac arrhythmias occurring most frequently.In view of the otherwise normal life expectancy of those affected, it is vitally important that the heart defect is treated.