Severe congenital neutropenia is a rare hematological disease characterized by a selective decrease in circulating neutrophils, maturation arrest of granulocytic precursors at the promyelocyte stage, and recurrence of infections. A 2-month-old male infant (patient A) and a 14-month-old female child (patient B) were referred to our hospital due to severe neutropenia. Sequencing analysis of ELA2 and HAX1 genes was performed. Two single nucleotide polymorphisms of HAX1 gene were found. They were 5,104T-->G point mutation of exon 1 and 5,474A-->G point mutation of intron 1 in HAX1 gene. The mutation of ELA2 gene was not found. The patient A showed a good response to granulocyte colony-stimulating factor (G-CSF) treatment and the absolute neutrophil count recovered to 1,195/microliter. But the patient B showed a partial response to G-CSF treatment and experienced several episodes of herpetic gingivostomatitis, oral ulcer, acute pharyngotonsillitis and otitis media during follow-up.
Adaptor Proteins, Signal Transducing/genetics ; Bone Marrow/pathology ; Female ; Granulocyte Colony Stimulating Factor, Recombinant/adverse effects/therapeutic use ; Humans ; Infant ; Male ; Neutropenia/congenital/drug therapy/*genetics ; Neutrophils/cytology/pathology ; Oral Ulcer/etiology ; Otitis Media/etiology ; Polymorphism, Single Nucleotide ; Serine Endopeptidases/genetics ; Stomatitis, Herpetic/etiology

Severe congenital neutropenia (SCN) is a heterogeneous group of disorders with a defect in granulopoiesis causing marked neutropenia and severe bacterial infections. A 17-month-old girl (patient 1) was admitted due to cervical lymphadenitis caused by methicillin-resistant Staphylococcus aureus, with neutropenia. She had Pseudomonas aeruginosa sepsis and peritonitis with perforated appendicitis at 8-month of age. Her sister, a 37-month-old girl (patient 2), had recurrent stomatitis with profound neutropenia, and her mother, a 32-yr-old woman (patient 3), had had recurrent stomatitis until her early 20s with neutropenia. We found an ELANE gene mutation (c.597+1G > A) from them in direct DNA sequencing analysis. Patients 1 and 2 did not respond to granulocyte colony stimulating factor and patient 1 was treated with prolonged antibiotics and excision. We demonstrated inherited SCN cases showing different severity even with the same mutation of the ELANE gene in a family.
Adult ; Child, Preschool ; DNA Mutational Analysis ; Female ; Granulocyte Colony-Stimulating Factor/therapeutic use ; Humans ; Infant ; Leukocyte Elastase/*genetics ; Methicillin-Resistant Staphylococcus aureus/isolation & purification ; Mutation/genetics ; Neutropenia/*congenital/diagnosis/drug therapy/genetics ; Pedigree ; *Phenotype ; Polymorphism, Single Nucleotide ; Recurrence ; Staphylococcal Infections/diagnosis/microbiology ; Stomatitis/diagnosis ; Tomography, X-Ray Computed