Purpose Multiple endocrine neoplasia type 1 is a rare tumor syndrome caused by germline mutations of MEN1 gene. Phenotype varies widely, and no definitive correlation with the genotype has been observed. Mutation-negative patients with MEN1-associated tumors represent phenocopies. By comparing mutation-positive and mutation-negative patients, we aimed to identify phenotype features predictive for a positive genetic test and to evaluate the role of MEN1 mutations in phenotype modulation. Methods Mutation screeening of MEN1 gene by Sanger sequencing and assessment of clinical data of 189 consecutively enrolled probands and relatives were performed at our national and European Reference Center. Multiple ligation probe amplification analysis of MEN1 gene and Sanger sequencing of CDKN1B were carried out in clinically suspicious but MEN1 -negative cases. Results Twenty-seven probands and twenty family members carried MEN1 mutations. Five mutations have not been described earlier. Pronouncedly high number of phenocopies (>70%) was observed. Clinical suspicion of MEN1 syndrome emerged at significantly earlier age in MEN1 -positive compared to MEN1 -negative probands. Gastroenteropancreatic neuroendocrine tumors developed significantly earlier and more frequently in carriers compared to non-carriers. Probands with high-impact (frameshift, nonsense, large deletions) mutations, predicted to affect menin function significantly, developed GEP-NETs more frequently compared to low-impact (inframe and missense) mutation carriers. Conclusions MEN1 phenocopy is common and represents a significant confounder for the genetic testing. GEP-NET under 30 years best predicted a MEN1 mutation. The present study thus confirmed a previous proposal and suggested that GEP-NET under 30 years should be considered as a part of the indication criteria for MEN1 mutational analysis.

Pheochromocytomas (Pheo) and paragangliomas (PGL) are rare tumors, with heterogeneous genetic background. In up to 30 % of all, apparently sporadic Pheo/PGL cases germline mutations can be identified in one of the 15 genes representing genetic susceptibility for Pheo/PGL. Malignancy is rare but it frequently associates with SDHB mutations. Our aim was to determine the prevalence of germline SDHx, SDHAF2, MAX and TMEM127 mutations in Hungarian patients with apparently sporadic Pheo/PGLs. Mutation screening of the SDHx, SDHAF2, MAX and TMEM127 genes was performed in 82 Hungarian patients with apparently sporadic Pheo/PGL using PCR and bidirectional Sanger sequencing. Disease-causing germline mutations were identified in 11 patients, of which 4 SDHB and 2 TMEM127 mutations were novel. Earlier development of Pheo/PGL, more malignant phenotype and multiple tumors were observed in genetically positive cases especially in those with SDHB mutations. The presence of bilateral or multiple tumors was the most predictive for identification of a pathogenic mutation. Together with cases harboring germline RET, VHL and NF1 mutations, Hungarian patients with Pheo/PGL exhibit a heterogeneous mutation spectrum, indicating that all of the Pheo/PGL susceptibility genes should be tested. Novel genotype-phenotype associations revealed by our study may contribute to improvement of diagnostic approaches and may help to achieve a better clinical follow up for patients with Pheo/PGL.

Gorlin-Goltz syndrome (GGS) or nevoid basal cell carcinoma syndrome is a rare tumour-overgrowth syndrome associated with multiple developmental anomalies and a wide variety of tumours. Here, we describe a case of a man aged 23 years with GGS with bilateral giant tumours adjacent to both adrenals that raised the suspicion of malignancy on imaging. Histological analysis of both surgically resected tumours revealed perivascular epitheloid cell tumours (PEComas) that were independent of the adrenals. Exome sequencing of the patient’s blood sample revealed a novel germline heterozygous frameshift mutation in the PTCH1 gene. As a second hit, a somatic five nucleotide long deletion in the PTCH1 gene was demonstrated in the tumour DNA of both PEComas. To the best of our knowledge, this is the first report on PEComa in GGS, and this finding also raises the potential relevance of PTCH1 mutations and altered sonic hedgehog signalling in PEComa pathogenesis. The presence of the same somatic mutation in the bilateral tumours might indicate the possibility of a postzygotic somatic mutation that along with the germline mutation of the same gene could represent an intriguing genetic phenomenon (type 2 segmental mosaicism).

A phaeochromocytoma a katecholamin-termelő mellékvesevelő neuroendokrin sejtjeinek daganata. Az extraadrenalisan elhelyezkedő phaeochromocytomákat paragangliomának nevezzük. A phaeochromocytomák nagy része sporadikusan fordul elő, de mintegy 25-30%-uk genetikai eredetű, örökletes forma. Az örökletes phaeochromocytomaparaganglioma szindrómák incidenciája folyamatosan növekszik. Ez egyrészt az egyre szélesebb körben elterjedő genetikai vizsgálatokkal, valamint az újabb gének felfedezésével függ össze. A középkorú nőbetegnél végzett komputertomográfia során derült fény kétoldali mellékvese-nagyobbodásra. A kiegészítő képalkotó vizsgálatok, a vizeletkatecholamin-és szérum-chromogranin-A-eredmények kétoldali phaeochromocytoma jelenlétét erősítették meg. A beteg egypetéjű ikertestvérénél is hasonló, hormonálisan aktív kétoldali phaeochromocytoma igazolódott, ezért felmerült öröklődő, familiáris phaeochromocytoma lehetősége. Ennek igazolására genetikai vizsgálat történt, ami a nemrégiben felismert transzmembrán protein 127 tumorszuppresszor gén mutációját igazolta. A kivizsgálást követően mindkét betegnél mellékvese-megtartó műtétre került sor, amely során a nagyobb daganatot tartalmazó mellékvesét teljes egészében reszekálták, míg az ellenkező oldalon a mellékvese velőállományát eltávolítva mellékvese-kéregállományt hagytak vissza. A műtétet követően mindkét betegnél a vizeletkatecholamin-és szérum-chromogranin-A-szintek normalizálódtak. A mellékvesekéreg-megtartó műtét ellenére az egyik betegnél mellékvesekéreg-elégtelen-ség alakult ki, ami miatt tartós glükokortikoidpótlásra szorul. Az eset különlegességét az adja, hogy az áttekintett irodalomban és a rendelkezésre álló nemzetközi phaeochromocytoma-regiszterekben sem egypetéjű, sem kétpetéjű ikerpárról a szerzők nem találtak említést. Az egész családra kiterjesztett genetikai vizsgálat során 4 generáción keresztül sikerült igazolni a mutáns gén jelenlétét. Orv. Hetil., 2016, 157(33), 1326-1330. Kulcsszavak: örökletes phaeochromocytoma, TMEM127 génmutáció, egypetéjű ikrek Hereditary phaeochromocytoma in twinsPhaeochromocytoma is a tumor of the catecholamine-producing cells of the adrenal gland. Extraadrenal phaeochromocytomas are frequently called paragangliomas. The majority of phaeochromocytomas are sporadic, however, about 25-30% are caused by genetic mutation. These tumor are frequently referred as hereditary phaeochromocytomas/ paragangliomas. Their incidence increases continuously which can be attributed to availability of genetic examination and to the discovery of novel genes. The 47-year-old female patient underwent abdominal computed tomography which revealed bilateral adrenal gland enlargement. Abdominal magnetic resonance imaging, the 131-I-metaiodobenzylguanidine scintigraphy, urinary catecholamines and serum chomogranin A measurements confirmed the diagnosis of bilateral phaeochromocytomas. The genetically identical twin sister of the patient was also diagnosed with hormonally active bilateral phaechromocytoma, suggesting the genetic origin of phaeochro...