[Clinical and genetic studies of a family with hereditary angioedema]

Objective: To diagnose a large family of patients with hereditary angioedema, and to study its inheritance pattern and gene locus. Methods: A retrospective analysis was carried out from August 2021 to February 2022 in a proband (female, 48 years old) and 12 family members who underwent medical history collection and laboratory examinations in the Department of Otorhinolaryngology and Head and Neck Surgery, the Second Hospital of Shanxi Medical University. The clinical data of members and non-affected members [including 7 males and 5 females, aged 12-78 (median 24) years old], were drawn a family map while confirming the diagnosis. Whole exome sequencing technology was used to detect the genetic sequence of the proband and to verify its family members to map the genetic pedigree of the mutation. Results: The inheritance pattern of the family was autosomal dominant, and 8 members of the family were diagnosed with hereditary angioedema by laboratory examination, including 7 cases of type I and 1 case of type Ⅱ. Whole exome sequencing analysis was performed on 2 patients with 2 phenotypes, and it was found that they both carried the same pathogenic mutation locus, which was c.890-2A>G. The family members were verified by next-generation sequencing, and it was found that all members of the family who had a history of edema contained this mutation site, while the younger brother of the proband who had no history of edema did not have this mutation. Conclusion: Both type Ⅰ and type Ⅱ phenotypes are present in this hereditary angioedema family, and the mutation of SERPING1 gene c.890-2A>G causes the onset of each patient in this family.