AR TRAC deficiency. (A) Pedigree of two Iranian families showing the familial segregation of mutant TRAC alleles, labeled as “M.” E?: unknown genotypes. mo, months old; yo, years old. (B) Left, spiral abdominopelvic CT scan demonstrating the presence of a large lymph node in the left paravertebral area (18 × 12 mm) and multiple small nonsignificant adenopathies consistent with intranodal abscesses following BCG-osis. Right, chest X-ray imaging revealing bilateral pneumonia in P2 (3 years old). (C) Flow cytometry analysis of peripheral blood lymphocytes from P2 (3 mo old) and an aged-matched control. (D) Frequency and combined annotation–dependent depletion (CADD) scores for variants present in the homozygous state in the gnomAD database (black dots) and for the TRAC mutations reported here or in previous studies (red dots).