In this patient, the deleted region included 1.4 kb of intron 1, the first exon of ARHGAP4 and a 2.8 kb sequence between ARHGAP4 and ARD1A; this sequence is highly conserved across species, and Broides et al, speculated that this conserved region was the cause of the immunodeficiency phenotype observed in their patient. Here, NAA10 is linked to Immunodeficiency.