Combined treatment with octreotide LAR and pegvisomant in patients with pituitary gigantism: clinical evaluation and genetic screening.

INTRODUCTION: Pituitary gigantism is a rare condition caused by growth hormone secreting hypersecretion, usually by a pituitary tumor. Acromegaly and gigantism cases that have a genetic cause are challenging to treat, due to large tumor size and poor responses to some medical therapies (e.g. AIP mutation affected cases and those with X-linked acrogigantism syndrome). MATERIALS AND METHODS: We performed a retrospective study to identify gigantism cases among 160 somatotropinoma patients treated between 1985 and 2015 at the University Hospital of Caracas, Venezuela. We studied clinical details at diagnosis, hormonal responses to therapy and undertook targeted genetic testing. Among the 160 cases, eight patients (six males; 75 %) were diagnosed with pituitary gigantism and underwent genetic analysis that included array comparative genome hybridization for Xq26.3 duplications. RESULTS: All patients had GH secreting pituitary macroadenomas that were difficult to control with conventional treatment options, such as surgery or primary somatostatin receptor ligand (SRL) therapy. Combined therapy (long-acting SRL and pegvisomant) as primary treatment or after pituitary surgery and radiotherapy permitted the normalization of IGF-1 levels and clinical improvement. Novel AIP mutations were the found in three patients. None of the patients had Xq26.3 microduplications. CONCLUSIONS: Treatment of pituitary gigantism is frequently challenging; delayed control increases the harmful effects of GH excess, such as, excessive stature and symptom burden, so early diagnosis and effective treatment are particularly important in these cases.

Identification and frequencies of cystic fibrosis mutations in central Argentina.

BACKGROUND: The Argentinian population is mainly of Caucasian origin, with a small contingent of indigenous descent. The aim of this study is to test the hypothesis that a panel of mutations designed for European countries is not optimal as a first-line molecular diagnosis for routine use in this country of mixed European origin. METHODS: Phenotype analyses combined with a European screening panel of 71 mutations followed by Sanger sequencing and large rearrangement study, were used to characterize the identification and distribution of CFTR mutations in the Santa Fe province of Argentina. RESULTS: Clinical review of 121 subjects suspected of CF during childhood led to selection of 83 unrelated patients. Thirty four different mutations, including two new ones, c.2554dupT and p.Leu49Pro, were detected. The total sensitivity was 91% (n = 151/166 alleles). CONCLUSIONS: Frequencies of CFTR mutations in Argentinian populations differ from those of their European ancestry. A new first line panel of 21 CFTR mutations with a sensitivity of 84% is proposed for routine use in central Argentina.

Variable pathological and clinical features of a large Brazilian family harboring a mutation in the aryl hydrocarbon receptor-interacting protein gene.

BACKGROUND: Germline aryl hydrocarbon receptor-interacting protein (AIP) mutations occur in 15% of familial isolated pituitary adenoma (FIPA) cases. To date, studies have focused on the identification of such mutations in large international cohorts. Detailed genetic and clinical studies within AIP mutation-positive families have been limited. AIM: To undertake a comprehensive study of a large Brazilian FIPA kindred with an E174 frameshift (E174fs) AIP mutation to assess clinical, hormonal, and radiological features in mutation carriers. METHODS: The kindred included 122 subjects across six generations; all underwent clinical examination. Genetic studies were performed to identify E174fs mutation carriers. E174fs-positive subjects underwent magnetic resonance imaging (MRI) and hormonal assessments. RESULTS: Of the ten germline AIP mutation carriers, three had pituitary tumors, while seven were asymptomatic carriers. Three patients with pituitary tumors showed variability in terms of tumor phenotype (two with acromegaly, one with prolactinoma, or mixed prolactin/GH-secreting tumor) and age at diagnosis; both patients with acromegaly had poor responses to octreotide. Tumor AIP immunohistochemistry from the operated patient showed decreased expression when compared with normal tissue. Two adult subjects with normal MRI had elevated IGF-I in the absence of other causes. A 2-year-old child with the E174fs mutation and a normal MRI had premature thelarche, ovarian development, and advanced bone age in the absence of other underlying causes. CONCLUSIONS: The penetrance of pituitary tumors in AIP mutation-positive adult subjects was 33.3%, while clinical/hormonal features were variable. The features noted in AIP-mutation carriers in this kindred suggest that clinical characteristics of such carriers may extend beyond pituitary tumors.