A neonate is note to have an abnormally shaped face with a very small jaw. On examination he has systolic murmur. Several hours after bih, the baby develops convulsions and tetany. Serum chemistries show Sodium 40mEq/L Potassium 4mEq/L Chloride 100mEq/L Bicarbonate 24mEq/ L Magnesium 2mEq/L Calcium 5mEq/dL Glucose 100mg/ dL This child's disorder is associated with aplasia or hypoplasia of which of the following organs?