Genetics, clinical features and outcomes of non-syndromic pituitary gigantism: experience of a single center from Sao Paulo, Brazil

Purpose Non-syndromic pituitary gigantism (PG) is a very rare disease. Aryl hydrocarbon receptor-interacting protein ( AIP ) and G protein-coupled receptor 101 ( GPR101 ) genetic abnormalities represent important etiologic causes of PG and may account for up to 40% of these cases. Here, we aimed to characterize the clinical and molecular findings and long-term outcomes in 18 patients (15 males, three females) with PG followed at a single tertiary center in Sao Paulo, Brazil. Methods Genetic testing for AIP and GPR101 were performed by DNA sequencing, droplet digital PCR and array comparative genomic hybridization (aCGH). Results Pathogenic variants in the AIP gene were detected in 25% of patients, including a novel variant in splicing regulatory sequences which was present in a sporadic male case. X-LAG due to GPR101 microduplication was diagnosed in two female patients (12.5%). Of interest, these patients had symptoms onset by age 5 and 9 years old and diagnosis at 5 and 15 years, respectively. X-LAG, but not AIP , patients had a significantly lower age of symptoms onset and diagnosis and a higher height Z-score when compared to non-X-LAG. No other differences in clinical features and/or treatment outcomes were observed among PG based on their genetic background. Conclusion We characterize the clinical and molecular findings and long-term outcome of the largest single-center PG cohort described so far.