NEIL1 is a candidate gene associated with common variable immunodeficiency in a patient with a chromosome 15q24 deletion

- We describe the first patient with a deletion of chromosome 15q associated with common variable immunodeficiency.
- NEIL1 is identified as the best candidate gene for leading immunodeficiency.
- NEIL1 plays multiple important roles in the DNA damage response and germinal center B cells proliferation and function.
- We suggest NEIL1 as a new potential candidate gene causing immunodeficiency in humans.

We report the first patient with an interstitial deletion of chromosome 15q24.1-q24.3 associated with common variable immunodeficiency (CVID). The 18-year old female patient's clinical and immunological phenotype was compared with 8 additional previously published patients with chr15q24 deletions. A CGH analysis estimated the deletion to be 3.767 Mb in size (chr15: 74,410,916-78,178,418) and the result was confirmed using qRT-PCR. We defined an immune-related commonly deleted region (ICDR) within the chromosomal band 15q24.2, deleted in all four patients with different forms of antibody deficiencies. Mutations in the 14 genes within this ICDR were not identified in the remaining allele in our patient by WES and gene expression analyses showed haploinsufficiency of all the genes. Among these genes, we consider Nei Like DNA Glycosylase 1 (NEIL1) as a likely candidate gene due to its crucial role in B-cell activation and terminal differentiation.