RESUMO
Context: Data on germline genetics of pituitary adenomas (PAs) using whole-exome sequencing (WES) are limited. Objective: This study investigated the germline genetic variants in patients with PAs using WES. Methods: We studied 134 consecutive functioning (80.6%) and nonfunctioning (19.4%) PAs in 61 female (45.5%) and 73 male patients (54.5%). Their median age was 34 years (range, 11-85 years) and 31 patients had microadenomas (23.0%) and 103 macroadenomas (77%). None of these patients had family history of PA or a known PA-associated syndrome. Peripheral blood DNA was isolated and whole-exome sequenced. We used American College of Medical Genetics and Genomics (ACMG) criteria and a number of in silico analysis tools to characterize genetic variant pathogenicity levels and focused on previously reported PA-associated genes. Results: We identified 35 variants of unknown significance (VUS) in 17 PA-associated genes occurring in 40 patients (29.8%). Although designated VUS by the strict ACGM criteria, they are predicted to be pathogenic by in silico analyses and their extremely low frequencies in 1000 genome, gnomAD, and the Saudi Genome Project databases. Further analysis of these variants by the Alpha Missense analysis tool yielded 8 likely pathogenic variants in 9 patients in the following genes: AIP:c.767C>T (p.S256F), CDH23:c.906G>C (p.E302D), CDH23:c.1096G>A (p.A366T), DICER1:c.620C>T (p.A207V), MLH1:c.955G>A (p.E319K), MSH2:c.148G>A (p.A50T), SDHA:c.869T>C (p.L290P) and USP48 (2 patients): c.2233G>A (p.V745M). Conclusion: This study suggests that about 6.7% of patients with apparently sporadic PAs carry likely pathogenic variants in PA-associated genes. These findings need further studies to confirm them.
RESUMO
Short Synacthen test (SST) involves measuring the baseline, 30-, and 60-minute serum cortisol levels, after injecting 250âµg of synthetic adrenocorticotropic hormone or Synacthen (ACTH). This study aimed to review the current clinical practice of performing SST to establish a standardized test protocol and to additionally test the hypothesis regarding performing the 60-minute cortisol test alone and the dependence of overall SST result on baseline cortisol level.Patients >14 years who underwent SST from January 2010 to December 2017 were included. Pearson's chi-square cross-tabulation was used to identify individuals with inconsistent 30- and 60-minute serum cortisol test results. Logistic regression analysis was performed to predict normal responses based on the baseline cortisol value.Of the 965 patients identified from pharmacy, medical, and laboratory records, 849 were included. Mean baseline, 30-, and 60-minute cortisol levels after ACTH injection were 394â±â286.58, 722â±â327.11, and 827â±â369.30ânmol/L, respectively. Overall, 715 (84%) and 134 (16%) patients had normal and abnormal responses, respectively. Primary and secondary adrenal insufficiency was diagnosed in 10% and 35%, respectively, while ACTH levels were not measured in 55% of the patients. Overall, 9.49% (nâ=â72) of the patients had a suboptimal response at 30 minutes, but reached the threshold value of 550ânmol/L at 60 minutes. This particular subgroup's mean change (240ânmol/L) in cortisol level from baseline to 30-minute was higher than that observed in patients with abnormal response at both time-points (mean change, 152ânmol/L). No patient with 30-minute optimal responses had 60-minute suboptimal responses. The baseline serum cortisol threshold of ≥226ânmol/L had 80% sensitivity, 71% specificity, and 93% positive predictive value for detecting a normal SST (P-valueâ<â.0001).Relying on a 60-minute cortisol level can identify all normal and abnormal responses, while relying on 30-minute cortisol level alone may produce false-positives. Additionally, a baseline cortisol level of ≥226ânmol/L is a reliable threshold for determining adequate adrenal function, particularly with a low pretest hypoadrenalism probability.