Method for in vitro analysis of the combinatorial diversity of the V J rearrangements of at least one genetic locus chosen from the TRA, TRB, TRG, TRD, IGH, IGK and IGL loci of a person from genomic DNA obtained from a biological sample taken from said person, comprising the following steps: A) amplifying fragments of said genomic DNA by multiplex polymerase chain reactions, at least one of which is a multi-n-plex PCR with n≥2, employing, in the same reaction, n different primer pairs, each enabling the amplification of at least two DNA fragments characteristic of at least two different chromosome rearrangements, effected with a combination of at least three primers, constituting at least two distinct primer pairs having the following characteristics: (i) three of said at least three primers constitute two distinct primer pairs; (ii) each primer pair consists of a primer specifically hybridising upstream of and/or in a given V or D gene and a primer specifically hybridising downstream of and/or in a given J gene, so as to enable the amplification of at least two fragments characteristic of two distinct V J or D-J rearrangements; (iii) the primers are thermodynamically compatible; (iv) the primers are chosen so that the fragments amplified with the first primer pair can be distinguished from the fragments amplified with the second primer pair; B) detecting the products of amplification obtained in the step A; C) interpreting the results. A) amplifying fragments of said genomic DNA by multiplex polymerase chain reactions, at least one of which is a multi-n-plex PCR with n≥2, employing, in the same reaction, n different primer pairs, each enabling the amplification of at least two DNA fragments characteristic of at least two different chromosome rearrangements, effected with a combination of at least three primers, constituting at least two distinct primer pairs having the following characteristics: (i) three of said at least three primers constitute two distinct primer pairs; (ii) each primer pair consists of a primer specifically hybridising upstream of and/or in a given V or D gene and a primer specifically hybridising downstream of and/or in a given J gene, so as to enable the amplification of at least two fragments characteristic of two distinct V J or D-J rearrangements; (iii) the primers are thermodynamically compatible; (iv) the primers are chosen so that the fragments amplified with the first primer pair can be distinguished from the fragments amplified with the second primer pair; (i) three of said at least three primers constitute two distinct primer pairs; (ii) each primer pair consists of a primer specifically hybridising upstream of and/or in a given V or D gene and a primer specifically hybridising downstream of and/or in a given J gene, so as to enable the amplification of at least two fragments characteristic of two distinct V J or D-J rearrangements; (iii) the primers are thermodynamically compatible; (iv) the primers are chosen so that the fragments amplified with the first primer pair can be distinguished from the fragments amplified with the second primer pair; B) detecting the products of amplification obtained in the step A; C) interpreting the results.