The most common heart defect are atrial septal defects which means there is a hole in the heart between the upper two heart chambers. The heart defect is often surgically corrected. EvC has been 'mapped' or localized to an area on chromosome number 4. However, the exact gene has not been found at this time. Briefly, the central feature of ATD is a small chest that appears long and narrow.
Some children die of respiratory distress in the neonatal period.
As the child gets older, the rib cage grows and the respiratory problems diminish. In addition, the nails are not small or unusual appearing. Older individuals with ATD often develop kidney dysfunction in later childhood which can lead to kidney failure in adulthood. Radiographically, the pelvis in individuals with ATD and EvC are similar. Some geneticists feel that ATD and EvC may actually be due to changes in the same gene and so represent different manifestations of the same gene.