Mary was born at term after an uncomplicated pregnancy. She had a low birth weight (2.1 kg), dysmorphic facial features, and a cleft palate. At 2 days old, she was diagnosed with truncus arteriosus and at 4 days old, she developed seizures. Tests showed that the cause of the seizures was hypocalcemia which resulted from low parathyroid hormone levels. An immune evaluation was performed at 2 weeks which showed low absolute numbers of lymphocytes and poor T cell function. What is your diagnosis and why? .