Background:Complete androgen insensitivity syndrome (CAIS, OMIM; 300068) is a disorder of sex development with X-linked recessive inheritance. Cases of CAIS usually present as female phenotype, with primary amenorrhea and/or inguinal hernia. Family aggregation is a rare scenario.Methods:This study is a retrospective analysis of CAIS cases in a three-generation pedigree. The patients’ genomes were determined by sequencing theandrogen receptor(AR) gene. The clinical data of the patients, including manifestations, hormone levels, andARvariants, were analyzed.Results:Sixteen people in this family were involved. A deletion variant (c.1847_1849del; p. Arg616del) was identified in exon 3 ofAR,which encodes the DNA binding domain. Until now, four patients and four carriers have been identified in three generations of this family. All the patients live as female, and one has developed gonadal malignancy.Conclusion:The present study identified a deletion variant in three generations of a family with CAIS, including four carriers and four patients. This study verified the genetic pattern and the corresponding clinical characteristics of CAIS. Furthermore, a case with gonadal malignancy was discovered. The information on diagnosis and treatment in this pedigree is useful for prenatal diagnosis and genetic counseling of similar families.