OBJECTIVE: The aryl hydrocarbon receptor interacting protein gene (AIP) is 
associated with pituitary adenoma (PA). AIP has not been sequenced in East Asian 
PA populations, so we performed this study in a Han Chinese cohort.
DESIGN: Our study included six familial PA pedigrees comprising 16 patients and 
27 unaffected relatives, as well as 216 sporadic PA (SPA) patients and 100 
unrelated healthy controls.
METHODS: AIP sequencing was carried out on genomic DNA isolated from blood 
samples. Multiplex ligation-dependent probe amplification and microsatellite 
marker analyses on DNA from the paired tumor tissues were performed for loss of 
heterozygosity analysis.
RESULTS: We identified three common and four rare single nucleotide 
polymorphisms (SNPs), one intron insertion, one novel synonymous variant, four 
novel missense variants, and a reported nonsense mutation in three familial 
isolated PA (FIPA) cases from the same family. Large genetic deletions were not 
observed in the germline but were seen in the sporadic tumor DNA from three 
missense variant carriers. The prevalence of AIP pathogenic variants in PA 
patients here was low (3.88%), but was higher in somatotropinoma patients 
(9.30%), especially in young adults (≤30 years) and pediatric (≥18 years) 
paients (17.24% and 25.00% respectively). All AIP variant patients suffered from 
macroadenomas. However, the AIP mutation rate in FIPA families was low in this 
cohort (16.67%, 1/6 families).
CONCLUSION: AIP gene mutation may not be frequent in FIPA or SPA from the Han 
Chinese population. AIP sequencing and long-term follow-up investigations should 
be performed for young patients with large PAs and their families with PA 
predisposition.