Genetics of Atrial Septal Defect

Of 109 cases of atrial septal defect, cases with an isolated defect (92 cases) showed a female preponderance (sex ratio 0·64), but there was a higher risk to the sibs of the male patients, suggesting a multifactorial mechanism. Dermatoglyphs showed a large number of whorls on the fingers. In 17 cases there were multiple malformations, such as Holt-Oram syndrome (hypoplastic and triphalangic thumb, with ostium secundum atrial septal defect), polydactyly plus ostium primum defect, and tracheo-oesophageal fistula.