(A) TCRBV usage in patient with AR-SCID (▪) and in healthy controls (▧). The relative percentage of TCRBV segments expression was calculated by normalizing the OD value of each individual TCRBV segment with respect to the sum of the OD values of all the 26 TCRBV chains as follows: % of expression:(B) Heteroduplex analysis of the indicated TCRBV chains prepared from patient's and control's lymphocytes after PCR amplification performed with TCRBV-specific primers. TCRBV8 amplified products, obtained from the amplification of the J77 and C1-632 cells RNA²⁹ were used as monoclonal and polyclonal controls and loaded, respectively, in the first and second lane of the gel. MW; molecular weight marker. (C) Junctional amino acid TCRBV2 and TCRBV5S1 sequences were deduced from nucleotide sequences and displayed as standard one-letter code. Only the last 3′ amino acids of the TCRBV segments and the first 5′ amino acids of TCRBJ chains are shown.