A heterogeneous genetic landscape was noted in the 7 neutropenia patients with pathogenic variants, two of whom were brothers who shared the same variant: ELANE (n = 4, 66.7%), G6PC3 (n = 1, 16.7%) and CXCR4 (n = 1, 16.7%). Here, CXCR4 is linked to Decreased total neutrophil count.