This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Immunity, Subject name: Pathology
A neonate develops spastic contractions on the second post-partum day Laboratory studies show hypocalcemia. MRI studies demonstrate aplasia of the thymus and parathyroid glands. What is the appropriate diagnosis? 
Select and explain. 
A. Adenosine deaminase deficiency, B. Common variable immunodeficiency, C. DiGeorge syndrome, D. Transient hypogammaglobulinemia of infancy
C: DiGeorge syndrome
Answer: C: DiGeorge syndrome 
Explanation: DiGeorge syndrome. DiGeorge syndrome is a chromosomal defect that results in developmental anomalies of the branchial (pharyngeal) pouches and organs that develop from these embryonic structures (thymus, parathyroids, and aortic arch). These children present with tetany caused by hypoparathyroidism and deficiency of cellular immunity. They also have characteristic facial features ("angry look"). In the absence of a thymus, T-cell maturation is interrupted at the pre-T stage. DiGeorge syndrome has been corrected by transplanting thymic tissue. None of the other choices are associated with thymic aplasia.Diagnosis: DiGeorge syndrome