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Abstract Background Congenital neutropenia is a rare disease. Recurrent infections since young age are the presentation. The most common mutation causing severe congenital neutropenia (SCN) and cyclic neutropenia (CyN) is the ELANE gene. The objectives of this study were to screen the three common genetic mutations of ELANE, HAX1 and GFI1 in children with chronic neutropenia and to describe the clinical characteristics of children who had the mutations. Methods Infants having ANC 1 year having ANC

Background: Congenital neutropenia is a rare disease. Recurrent infections since young age are the presentation. The most common mutation causing severe congenital neutropenia (SCN) and cyclic neutropenia (CyN) is the ELANE gene. The objectives of this study were to screen the three common genetic mutations of ELANE, HAX1 and GFI1 in children with chronic neutropenia and to describe the clinical characteristics of children who had the mutations. Methods: Infants having ANC < 1,000/cu mm or children aged > 1 year having ANC < 1,500/cu mm at least 3 times in 3 months were enrolled in the study. Patients who had acquired neutropenia due to infection, immune deficiency, or drugs were excluded. The ELANE gene was first studied; and if mutations were not identified, the HAX1 and GFI1 genes were further examined. Results: A total of 60 patients were enrolled in the study. The median (range) age, ratio of female to male, ANC, and last follow-up age were 9.2 (0.5–45.2) months, 1:1.2, 248 (0–1,101) /cu mm, and 19.9 (3.5–202.3) months, respectively. Infections were noted in 67.3% of all patients. ELANE gene mutation was found in only four patients (6.7%), and the rest (56 patients) showed no mutations in the HAX1 and GFI1 genes. In patients without mutations, 66.0% had normal ANC during the follow-up, with a median (range) age for normal ANC of 19.8 (4.0–60.0) months. Two novel mutations p. Ala79del (c.234_236del) and p. Val197GlufsTer18 (c.589_590insAGGCCGGC) were identified, and they respectively cause SCN and CyN. Patients with the two novel mutations presented with several episodes of infection, including pneumonia, sepsis, abscess, otitis media, and gum infection. Conclusion: The genetic screening for ELANE, HAX1, and GFI1 gene mutations in 60 patients with chronic neutropenia could identify four patients (6.7%) with ELANE gene mutation and two novel mutations, p. Ala79del in exon 3 and p. Val197GlufsTer18 in exon 4 causing SCN; and CyN, respectively. [ABSTRACT FROM AUTHOR]

Abstract Background IgA nephropathy (IgAN) is universally recognized as one of the most common primary glomerular diseases in all ages. Cyclic neutropenia (CN) is a rare haematologic disorder that is associated with mutations of the ELANE gene. The co-occurrence of IgAN and CN is extremely rare. This is the first case report of a patient with IgAN and genetically confirmed CN. Case presentation We report a case of a 10-year-old boy who presented with recurrent viral upper respiratory tract infections accompanied by several episodes of febrile neutropenia, haematuria, proteinuria and acute kidney injury. Upon first admission, his physical examination was unremarkable. His kidney function was impaired, whereas his urine microscopy showed evidence of macroscopic haematuria and proteinuria. Further workup showed elevated IgA. The renal histology was consistent with mesangial and endocapillary hypercellularity with mild crescentic lesions, while immunofluorescence microscopy showed IgA-positive staining, which was characteristic of IgAN. Moreover, genetic testing confirmed the clinical diagnosis of CN, therefore Granulocyte colony-stimulating factor (G-CSF) was initiated to stabilize the neutrophil count. Regarding proteinuria control, the patient was initially treated with an Angiotensin-converting-enzyme inhibitor for approximately 28 months. However, due to progressive proteinuria (> 1 g/24 h), Corticosteroids (CS) were added for a period of 6 months according to the revised 2021 KDIGO guidelines with favorable outcome. Conclusions Patients with CN are more susceptible to recurrent viral infections, which can trigger IgAN attacks. In our case CS induced remarkable proteinuria remission. The use of G-CSF contributed to the resolution of severe neutropenic episodes, viral infections and concomitant AKI episodes, contributing to better prognosis of IgAN. Further studies are mandatory to determine whether there is a genetical predisposition for IgAN in children with CN.

Cyclic neutropenia is a rare hematological condition characterized by periodic fluctuations in neutrophil counts, with a 21-day periodicity. Clinical presentation varies from mild to severe forms of the disease, with the onset of recurrent fever, painful oral ulcers, recurrent bacterial infections, peritonitis, and septic shock. The availability of granulocyte colony-stimulating factor (G-CSF) has revolutionized the management and natural history of this disease, regulating the proliferation, differentiation, and maturation of the progenitor cells, and reducing the duration of neutropenia. Inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC), is a group of chronic pathologies that affect the gastrointestinal tract. The onset of both diseases may be at a young age (even during childhood or adolescence), and clinical manifestations may lead to misdiagnosis, due to similar characteristics such as recurrent infections, oral ulcers, perianal abscesses, and infertility. Moreover, the two pathologies are rarely associated, with different management and therapeutic options. Here, we describe two case reports of patients who underwent surgery because of diagnosis of complicated CD. After surgery, due to persistent neutropenia, the hematologist consultant confirmed suspicions of cyclic neutropenia, and G-CSF therapy was started with benefits, underlining the crucial importance of proper differential diagnosis. [ABSTRACT FROM AUTHOR]

Background: IgA nephropathy (IgAN) is universally recognized as one of the most common primary glomerular diseases in all ages. Cyclic neutropenia (CN) is a rare haematologic disorder that is associated with mutations of the ELANE gene. The co-occurrence of IgAN and CN is extremely rare. This is the first case report of a patient with IgAN and genetically confirmed CN. Case presentation: We report a case of a 10-year-old boy who presented with recurrent viral upper respiratory tract infections accompanied by several episodes of febrile neutropenia, haematuria, proteinuria and acute kidney injury. Upon first admission, his physical examination was unremarkable. His kidney function was impaired, whereas his urine microscopy showed evidence of macroscopic haematuria and proteinuria. Further workup showed elevated IgA. The renal histology was consistent with mesangial and endocapillary hypercellularity with mild crescentic lesions, while immunofluorescence microscopy showed IgA-positive staining, which was characteristic of IgAN. Moreover, genetic testing confirmed the clinical diagnosis of CN, therefore Granulocyte colony-stimulating factor (G-CSF) was initiated to stabilize the neutrophil count. Regarding proteinuria control, the patient was initially treated with an Angiotensin-converting-enzyme inhibitor for approximately 28 months. However, due to progressive proteinuria (> 1 g/24 h), Corticosteroids (CS) were added for a period of 6 months according to the revised 2021 KDIGO guidelines with favorable outcome. Conclusions: Patients with CN are more susceptible to recurrent viral infections, which can trigger IgAN attacks. In our case CS induced remarkable proteinuria remission. The use of G-CSF contributed to the resolution of severe neutropenic episodes, viral infections and concomitant AKI episodes, contributing to better prognosis of IgAN. Further studies are mandatory to determine whether there is a genetical predisposition for IgAN in children with CN. [ABSTRACT FROM AUTHOR]

Clostridium septicum is a very rare cause of severe spontaneous pediatric enterocolitis and is often associated with underlying malignancy or immunocompromise. Likewise, cyclic neutropenia is a rare congenital immunodeficiency that is characterized by cyclical periods of neutropenia, often with more severe symptoms in the pediatric population. Here, we present a unique case of spontaneous C. septicum enterocolitis, sepsis, and myonecrosis in a child with undiagnosed cyclic neutropenia. Early recognition of pediatric sepsis, frequent reevaluation and identification of rapidly progressive infection, and early surgical intervention are critical for the effective management of a rare and severe infection. [ABSTRACT FROM AUTHOR]

Cyclic neutropenia (CyN) is a rare, ELANE-related neutropenia. Oral manifestations are among the initial signs of CyN and an important reason that leads patients to seek professional help. This case report describes a 12-year-old girl with recurrent oral ulcers, severe chronic periodontitis, and pathological tooth migration as the initial and main clinical symptoms of CyN. Two novel mutations in ELANE,c.180T>G(p.I60M)and c.182C>G (p.A61G) associated with CyN were observed. Bioinformatics research indicated lower stability and impaired molecular linkages of the mutant neutrophil elastase (NE) encoded by ELANE.However,theenzymeaffinity to the classic substrate Suc--Ala--Ala--Ala--pNA was not substantially changed, suggesting that the impaired integrity and stability of the mutant NE, rather than catalytic deficiency, might be the pathogenic mechanism of ELANE mutation-induced neutropenia. The patient was prescribed scaling and root planing (SRP) andmonthly periodontalmaintenancewithout systemic management. Although the routine periodontal treatment was occasionally interrupted by the 2019 coronavirus pandemic, her periodontal devastation remained well-remitted in the 5-year follow-up assessment. The results of this study confirmed the importance of plaque control and proper diagnosis in the periodontal management of such patients and provide better clinical references. In addition, the novel mutations identified in this study expand the spectrum of known ELANE mutations in CyN and further contribute to knowledge regarding its pathogenic mechanism. [ABSTRACT FROM AUTHOR]

Autosomal dominant mutations in the signal recognition particle (SRP) 54 gene were recently described in patients with severe congenital neutropenia (SCN). SRP54 deficiency cause a chronic and profound neutropenia with maturation arrest at the promyelocyte stage, occurring in the first months of life. Nearly all reported patients with SRP54 mutations had neutropenia without a cyclic pattern and showed a poor or no response to granulocyte colonystimulating factor (G-CSF) therapy. We report here an 11-year-old female patient with cyclic neutropenia and recurrent heterozygous p. T117del (c.349_351del) in-frame deletion mutation in SRP54, who showed remarkable therapeutic response to G-CSF treatment. The diagnosis of cyclic pattern of neutropenia was established by acceptable standards. ELANE gene mutation was excluded by using various genetic approaches. The patient described here also had dolichocolon which has not been described before in association with SCN. [ABSTRACT FROM AUTHOR]

Autosomal dominant mutations in the signal recognition particle (SRP) 54 gene were recently described in patients with severe congenital neutropenia (SCN). SRP54 deficiency cause a chronic and profound neutropenia with maturation arrest at the promyelocyte stage, occurring in the first months of life. Nearly all reported patients with SRP54 mutations had neutropenia without a cyclic pattern and showed a poor or no response to granulocyte colony-stimulating factor (G-CSF) therapy. We report here an 11-year-old female patient with cyclic neutropenia and recurrent heterozygous p.T117del (c.349_351del) in-frame deletion mutation in SRP54, who showed remarkable therapeutic response to G-CSF treatment. The diagnosis of cyclic pattern of neutropenia was established by acceptable standards. ELANE gene mutation was excluded by using various genetic approaches. The patient described here also had dolichocolon which has not been described before in association with SCN.

Abstract Background Cyclic neutropenia is a disease that causes a neutropenic decrease in peripheral blood in a cycle of about 21 days. It is a rare hereditary disorder with an estimated incidence of 0.5–1 cases per million population. The absolute neutrophil count can drop to zero, and neutropenic nadir may last for 3–5 days. This is a rare disease, and there are few reports of abdominal surgery in cyclic neutropenia patients; thus, we report this case of neutrophil count fluctuation and perioperative management. Case presentation A 31-year-old man with cyclic neutropenia was transferred to our hospital complaining of right season rib pain, but no rebound tenderness. His C-reactive protein was elevated (4.37 mg/L) and computed tomography revealed a large number of small stones in the gallbladder body and an incarceration in the gallbladder neck. He was diagnosed with acute cholecystitis. Ideally, surgical intervention should have been performed immediately, but because his neutrophil count was 300/μL, endoscopic naso-gallbladder drainage was performed and he was provided antibiotics until his neutrophil count increased to acceptable levels. Three days after admission, his neutrophil count had increased and laparoscopic cholecystectomy was performed. For one week after the operation, antibiotics were administered; he had an uneventful postoperative recovery. He was discharged on the seventh postoperative day and provided an oral antibiotic. Conclusions Infection can be serious in patients with cyclic neutropenia, and it is therefore, important to determine the timing of surgery and to apply appropriate perioperative management with drainage and antibiotic administration.

A disparate group of rare hematological diseases characterized by impaired maturation of neutrophil granulocytes defines congenital neutropenias. Neutropenic patients are prone to recurrent infections beginning in the first months of life. Of interest is “cyclic neutropenia”, an ultra-rare disorder revealed by sinusoidal variations of the neutrophil count and periodically-recurring infections every 21 days. Diagnosis of these disorders is frequently obscured by the multiple causes of recurrent fevers in children. Aim of this overview is to outline the physical assessment of children presenting with early-onset symptomatic neutropenia, identify the disease between the many medical conditions and even emergencies which should enter in differential diagnosis, hint at the potential management with granulocyte-colony stimulating factor, define the risk of evolution to hematologic malignancy, and summarize inter-professional team strategies for improving care coordination and outcomes of such patients.

Severe congenital neutropenia (SCN) is a rare hematological condition with heterogenous genetic background. Neutrophil elastase (NE) encoded by ELANE gene is mutated in over half of the SCN cases. The role of NE defects in myelocytes maturation arrest in bone marrow is widely investigated; however, the mechanism underlying this phenomenon has still remained unclear. In this review, we sum up the studies exploring mechanisms of neutrophil deficiency, biological role of NE in neutrophil and the effects of ELANE mutation and neutropenia pathogenesis. We also explain the hypotheses presented so far and summarize options of neutropenia therapy.

Severe congenital neutropenia (SCN) is a rare hematological condition with heterogenous genetic background. Neutrophil elastase (NE) encoded by ELANE gene is mutated in over half of the SCN cases. The role of NE defects in myelocytes maturation arrest in bone marrow is widely investigated; however, the mechanism underlying this phenomenon has still remained unclear. In this review, we sum up the studies exploring mechanisms of neutrophil deficiency, biological role of NE in neutrophil and the effects of ELANE mutation and neutropenia pathogenesis. We also explain the hypotheses presented so far and summarize options of neutropenia therapy. [ABSTRACT FROM AUTHOR]

Nicotinamide (vitamin B3) treatment improves response to G-CSF in severe congenital neutropenia patients Keywords: severe congenital neutropenia; cyclic neutropenia; granulocyte colony-stimulating factor; nicotinamide; vitamin B3 EN severe congenital neutropenia cyclic neutropenia granulocyte colony-stimulating factor nicotinamide vitamin B3 788 792 5 02/17/21 20210215 NES 210215 Severe congenital neutropenia (CN) is an inherited bone marrow failure syndrome with markedly reduced granulocyte number and function that often manifests with life-threatening bacterial infections.1 Granulocyte colony-stimulating factor (G-CSF) treatment is the primary therapeutic approach and is aimed at keeping granulocyte levels at or above 1 000/µl to prevent infectious complications.2 Some CN patients require high doses of G-CSF to reach this goal, and a small group of patients is not responsive to G-CSF therapy at all. GLO:1XW/15feb21:bjh17313-fig-0001.jpg PHOTO (COLOR): 1 Effect of nicotinamide (NA) treatment on blood cell counts in congenital neutropenia (CN) and cyclic neutropenia (CyN) patients. [Extracted from the article]

Background: Cyclic neutropenia is a disease that causes a neutropenic decrease in peripheral blood in a cycle of about 21 days. It is a rare hereditary disorder with an estimated incidence of 0.5–1 cases per million population. The absolute neutrophil count can drop to zero, and neutropenic nadir may last for 3–5 days. This is a rare disease, and there are few reports of abdominal surgery in cyclic neutropenia patients; thus, we report this case of neutrophil count fluctuation and perioperative management. Case presentation: A 31-year-old man with cyclic neutropenia was transferred to our hospital complaining of right season rib pain, but no rebound tenderness. His C-reactive protein was elevated (4.37 mg/L) and computed tomography revealed a large number of small stones in the gallbladder body and an incarceration in the gallbladder neck. He was diagnosed with acute cholecystitis. Ideally, surgical intervention should have been performed immediately, but because his neutrophil count was 300/μL, endoscopic naso-gallbladder drainage was performed and he was provided antibiotics until his neutrophil count increased to acceptable levels. Three days after admission, his neutrophil count had increased and laparoscopic cholecystectomy was performed. For one week after the operation, antibiotics were administered; he had an uneventful postoperative recovery. He was discharged on the seventh postoperative day and provided an oral antibiotic. Conclusions: Infection can be serious in patients with cyclic neutropenia, and it is therefore, important to determine the timing of surgery and to apply appropriate perioperative management with drainage and antibiotic administration. [ABSTRACT FROM AUTHOR]

Neutropenic syndrome is quite common in pediatric practice. Its nature is diverse, and every case of neutropenia needs thorough differential diagnosis to determine the patient’s management. Only a differentiated approach to patients with neutropenia can prevent the development of severe complications of infectious processes. To illustratу this point, we present a clinical case of severe chronic bronchopulmonary disease in a 4-year-old child, who was examined and treated in children’s city pulmonology center. The child was admitted to the hospital with the complaints of persistent non-productive cough, episodic distal rales, loss of hearing. From the history of the disease it was found that from one month of age, the child had repeated otitis, relapsing bronchitis with bronchial obstructive syndrome, repeated pneumonia of different localization. A comprehensive examination including, in addition to standard laboratory tests, diagnostic and diagnostic bronchoscopy, computed tomography of the thoracic organs, revealed a bilateral diffuse catarrhal-purulent endobronchitis, computed tomography signs of diffuse interstitial changes in the lungs and bronchomalacia. A thorough dynamic analysis of hemograms from the outpatient card made it possible to suspect a congenital neutropenia in the patient. Multiple occurrence of neutropenic crises with a decrease in the number of neutrophils to 1,000 cells/μl and lower during the first year of the child’s life and their periodicity of 3–4 weeks confirmed the cyclical nature of neutropenia. The sternal puncture performed with the evaluation of the myelogram revealed no significant changes in the granulocyte number that was probably due to the period of remission of cyclic neutropenia at the time of examination. Thus, severe chronic respiratory disease in this child was clinical mask of cyclic neutropenia, which required a thorough diagnosis. Neutropenia in children should be considered by the practicing physician as a laboratory symptom, which requires understanding, comparison with clinical manifestations and obligatory dynamic analysis.

Neutropenia is a hematological condition characterized by a decrease in absolute neutrophil count (ANC) in peripheral blood, typically classified in adults as mild (1–1.5 × 109/L), moderate (0.5–1 × 109/L), or severe (< 0.5 × 109/L). It can be categorized into two types: congenital and acquired. Congenital severe chronic neutropenia (SCN) arises from mutations in various genes, with different inheritance patterns, including autosomal recessive, autosomal dominant, and X-linked forms, often linked to mitochondrial diseases. The most common genetic cause is alterations in the ELANE gene. Some cases exist as non-syndromic neutropenia within the SCN spectrum, where genetic origins remain unidentified. The clinical consequences of congenital neutropenia depend on granulocyte levels and dysfunction. Infants with this condition often experience recurrent bacterial infections, with approximately half facing severe infections within their first six months of life. These infections commonly affect the respiratory system, digestive tract, and skin, resulting in symptoms like fever, abscesses, and even sepsis. The severity of these symptoms varies, and the specific organs and systems affected depend on the genetic defect. Congenital neutropenia elevates the risk of developing acute myeloid leukemia (AML) or myelodysplastic syndromes (MDS), particularly with certain genetic variants. SCN patients may acquire CSF3R and RUNX1 mutations, which can predict the development of leukemia. It is important to note that high-dose granulocyte colony-stimulating factor (G-CSF) treatment may have the potential to promote leukemogenesis. Treatment for neutropenia involves antibiotics, drugs that boost neutrophil production, or bone marrow transplants. Immediate treatment is essential due to the heightened risk of severe infections. In severe congenital or cyclic neutropenia (CyN), the primary therapy is G-CSF, often combined with antibiotics. The G-CSF dosage is gradually increased to normalize neutrophil counts. Hematopoietic stem cell transplants are considered for non-responders or those at risk of AML/MDS. In cases of WHIM syndrome, CXCR4 inhibitors can be effective. Future treatments may involve gene editing and the use of the diabetes drug empagliflozin to alleviate neutropenia symptoms. [ABSTRACT FROM AUTHOR]

Mutations in the ELANE gene, which encodes the neutrophil elastase (NE) protein in neutrophils, result in ELANE-related neutropenia. ELANE-related neutropenia encompasses both cyclic neutropenia (CN) and severe congenital neutropenia (SCN), with ELANE mutations seen in a majority of SCN and almost all of CN patients. Clinical history in affected individuals typically reveals recurrent episodes of fever, oral ulcerations and bacterial as well as fungal infections, correlating with periodic oscillations or chronically low levels in the absolute neutrophil count (ANC). ELANE-related neutropenia is characterised by severely low neutrophil counts where ANCs may drop as low as zero. A two-year-old child presented at our hospital with a longstanding history of recurrent bacterial infections and previous admissions at another centre during some of these infectious episodes. Her full blood count demonstrated a markedly low ANC, which was chronic on assessment of her previous results. Decreased granulopoiesis with maturation arrest was seen on her bone marrow and genetic testing for the ELANE gene demonstrated a pathogenic variant of the mutation. Treatment with granulocyte colony-stimulating factor (G-CSF) was initiated. [ABSTRACT FROM AUTHOR]

Key Clinical Message: Cyclic thrombocytopenia is often misdiagnosed as immune thrombocytopenia due to similar clinical features, a fact of significance because cyclic thrombocytopenia generally responds poorly to treatments used successfully in immune thrombocytopenia. A precise diagnosis must establish the statistical significance of periodicity of the platelet counts using statistical methods (eg, Lomb‐Scargle periodogram). [ABSTRACT FROM AUTHOR]

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Inhibitors of NE improve survival and differentiation of iPSC and HL60 cells expressing mutant NE. Mutations in ELANE, the gene for neutrophil elastase (NE), a protease expressed early in neutrophil development, are the most frequent cause of cyclic (CyN) and severe congenital neutropenia (SCN). We hypothesized that inhibitors of NE, acting either by directly inhibiting enzymatic activity or as chaperones for the mutant protein, might be effective as therapy for CyN and SCN. We investigated β‐lactam–based inhibitors of human NE (Merck Research Laboratories, Kenilworth, NJ, USA), focusing on 1 inhibitor called MK0339, a potent, orally absorbed agent that had been tested in clinical trials and shown to have a favorable safety profile. Because fresh, primary bone marrow cells are rarely available in sufficient quantities for research studies, we used 3 cellular models: patient‐derived, induced pluripotent stem cells (iPSCs); HL60 cells transiently expressing mutant NE; and HL60 cells with regulated expression of the mutant enzyme. In all 3 models, the cells expressing the mutant enzyme had reduced survival as measured with annexin V and FACS. Coincubation with the inhibitors, particularly MK0339, promoted cell survival and increased formation of mature neutrophils. These studies suggest that cell‐permeable inhibitors of neutrophil elastase show promise as novel therapies for ELANE‐associated neutropenia. [ABSTRACT FROM AUTHOR]

We report a rare case of chronic refractory uveitis in a patient with childhood-onset cyclic neutropenia (CN). A 19-year-old woman, who had a history of CN beginning at age 2, presented with bilateral chronic nongranulomatous uveitis, complicated cataract, retinal vasculitis, cystoids macular edema, and vitreous hemorrhage. She had recurrent episodes of oral ulcers, tonsillitis, genital ulcers, and folliculitis during neutropenic nadir. After the resumption of granulocyte colony-stimulating factor therapy for her CN, vitreous hemorrhage in both eyes followed. Her eyes were treated with topical corticosteroids, retinal photocoagulation, and cataract surgery. Blood and bone marrow test results confirmed the diagnosis of CN. She also fulfilled the diagnostic criteria of Behçet’s disease, though clinical features of her uveitis were dissimilar to those found in that disease.

Background: Mutations of ELA2, the gene encoding neutrophil elastase (NE) are known to be associated with cyclic neutropenia (CN) and severe congenital neutropenia (SCN). However, high variability of these mutations has been reported. This study was designed to describe the analysis of the ELA2 gene, clinical manifestations and demographic characteristics in patients with CN and SCN.Methods: A series of 21 patients with CN or SCN were selected, based on SCINR criteria, from the immunology ward of the Pediatric Medicine Center, Tehran, Iran, from March 2004 to August 2005. The ELA2 gene, isolated from blood samples, was analyzed using RT-PCR and automated capillary sequencing. Informed consent was obtained under the tenets of the Helsinki Declaration and the Ethical Committee of the Tehran University of Medical Sciences.Results: Kostmann's syndrome and CN was diagnosed in three and 18 patients respectively. Of all the patients, one or two mutations were found in 18 cases (85.7%), including all three patients with SCN and 15 of the patients with CN. Exons two and four had the most mutations (eight and seven cases, respectively). Seven patients had double mutations in two distinct exons. Overall, 16 different mutations were found. At the time of presentation, the mean age of patients was 13.4 ±17.6 months, ranging from one month to seven years. Overall, 61.9% of patients had consanguineous parents. The mean absolute neutrophil count was 830.5 ±419.4 (150-2000)/mm3. On average, each patient had been admitted to the hospital 2.2 ±1.6 times. The neutrophil counts of the SCN patients were significantly higher than those of the CN patients. However, there was no significant difference in the neutrophil counts between patients with mutations and those without mutations. All patients with SCN had two or more infectious complications, although the prevalence of infectious or non-infectious complications did not correlate with ELA2 mutations or the neutropenic disorders.Conclusion: Mutations in ELA2 appear to play an important role in the phatogenetic mechanisms of CN and SCN. Patients with CN had significantly higher neutrophil counts than SCN patients with CN. Although it possible for the gene encoding neutrophil elastase to have more than one mutation in distinct exons, we found no association between the mutations in ELA2 and their complications in CN and SCN patients.