class="h4">Objective

We sought to investigate the molecular basis for phenotypic diversity presented in patients with various RAG1 mutations.

class="h4">Methods

We have developed a flow cytometry-based assay that allows analysis of RAG recombination activity based on green fluorescent protein expression and have assessed the induction of the Ighc locus rearrangements in mouse Rag1^{鈭?鈭?/sup> pro-B cells reconstituted with wild-type or mutant human RAG1 (hRAG1) using deep sequencing technology.}

class="h4">Results

Here we demonstrate correlation between defective recombination activity of hRAG1 mutant proteins and severity of the clinical and immunologic phenotype and provide insights on the molecular mechanisms accounting for such phenotypic diversity.

class="h4">Conclusions

Using a sensitive assay to measure the RAG1 activity level of 79 mutations in a physiologic setting, we demonstrate correlation between recombination activity of RAG1 mutants and the severity of clinical presentation and show that RAG1 mutants can induce specific abnormalities of the VDJ recombination process.