Introduction: Severe congenital neutropenias (SCN) are a heterogeneous group of rare hematological diseases characterized by impaired maturation of neutrophil granulocytes. Patients with severe congenital neutropenia are prone to recurrent, often life-threatening infections beginning in their first months of life. The most frequent pathogenic defects is autosomal dominant mutations in ELANE gene (19p13.3), which encodes the serine protease neutrophil elastase, a pleiotropic enzyme involved in innate host defense, tissue remodeling, and local inflammatory response mediated by neutrophil and monocyte granules. A substitution of the 607th base (G to C) in exon 5 in ELANE, resulting in a change of the 203rd codon (glycine to arginine), which is a missense variation of SCN (c.607G > C; p.Gly203Arg, rs201139487), Intracellular accumulation and mislocalization of the mutant neutrophil elastase induces endoplasmic reticulum (ER) stress and activates the unfolded protein response (UPR). The present study identified the pathogenic variant rs201139487 in patients with SCN. Method: DNA was isolated from 4 milliliters of whole blood obtained from patients with SCN, and then typed for the rs201139487 by Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP). In brief, a 127 bp (base pairs) fragment was amplified and subjected to digestion with the MSPI and ACI1 enzymes. The variants results were visualized in 6% polyacrylamide (PAGE) and stained with 2% silver nitrate. MspI identifies the G, and AciI recognizes C alleles. Upon identifying the mutation (C), a digestion pattern of 99 and 28 bp was observed. Results: Among a cohort of 29 patients, the variant was successfully identified in 10% of the population (3 patients) with SCN. Conclusions: It is advisable to persist in the genotyping of patients with SCN, further validating the rs201139487 variant through sequencing, thereby emphasizing its significance in the pathogenesis of this condition.