Two rare case reports of familial cyclic neutropenia caused by ELANE gene mutation.

rationaleThis article presents 2 exceptionally rare cases of familial cyclic neutropenia (CN), along with a comprehensive review of the relevant literature. It further explores the clinical manifestations, laboratory examination characteristics, diagnostic approaches, and treatment strategies, as well as prognosis associated with CN. The aim of this paper is to enhance clinicians' awareness of these rare diseases, thereby facilitating early diagnosis and appropriate management. PATIENT CONCERNS: Case 1: a 47-year-old female who had suffered from bacillary dysentery, recurrent rectal abscess, anal fistula, gingivitis, and periodontitis from the age of 28, otherwise she had suffered from upper respiratory tract infection twice or 3 times every year with neutrophil count nadir of 0.18 × 109/L. Exome sequencing of blood of the woman and her family revealed this woman and her 7 years old daughter had the same c.416C > T(p.P139L) heterozygous mutation in the ELANE gene. Case 2: this patient was the daughter of case 1. The patient developed bronchial infection from the age of 2, and the blood routine showed the neutrophils were abnormally low. In addition, repeated cough, sputum and fever occurred during the year, and neut decreased in 7 of the 11 routine blood tests. The result of exome sequencing of blood revealed that she had the same c.416C > T(p.P139L) heterozygous mutation in the ELANE gene. DIAGNOSES: The 2 patients were diagnosed with familial CN.

interventionsIntermittent Chinese medicine, pidotimod, mannanopeptide treatment, and symptomatic treatment. OUTCOMES: A rare case of familial transmission involving 2 instances of mother-daughter pairs. Blood exome sequencing revealed that both pairs harbored the identical heterozygous mutation c.416C > T(p.P139L) in the ELANE gene, leading to a definitive diagnosis of familial CN caused by this ELANE gene mutation. At present, the patients' conditions are improved and the outpatient clinic is followed up regularly. LESSONS: If the patient presents with recurrent infections, fever, and other periodic symptoms annually, accompanied by neutropenia as indicated by a complete blood count, CN should be considered as a potential diagnosis. Genetic testing is imperative to ascertain the presence of any gene mutations for an accurate diagnosis. Cyclic neutropenia can be diagnosed based on the patient's clinical manifestations, laboratory tests, and genetic testing results.