Weaver Syndrome-Associated EZH2 Protein Variants Show Impaired Histone Methyltransferase Function In Vitro.

Weaver syndrome (WS) is a rare congenital disorder characterized by generalized overgrowth, macrocephaly, specific facial features, accelerated bone age, intellectual disability, and susceptibility to cancers. De novo mutations in the enhancer of zeste homolog 2 (EZH2) have been shown to cause WS. EZH2 is a histone methyltransferase that acts as the catalytic agent of the polycomb-repressive complex 2 (PRC2) to maintain gene repression via methylation of lysine 27 on histone H3 (H3K27). Functional studies investigating histone methyltransferase activity of mutant EZH2 from various cancers have been reported, whereas WS-associated mutations remain poorly characterized. To investigate the role of EZH2 in WS, we performed functional studies using artificially assembled PRC2 complexes containing mutagenized human EZH2 that reflected the codon changes predicted from patients with WS. We found that WS-associated amino acid alterations reduce the histone methyltransferase function of EZH2 in this in vitro assay. Our results support the hypothesis that WS is caused by constitutional mutations in EZH2 that alter the histone methyltransferase function of PRC2. However, histone methyltransferase activities of different EZH2 variants do not appear to correlate directly with the phenotypic variability between WS patients and individuals with a common c.553G>C (p.Asp185His) polymorphism in EZH2.

Is intraoperative calcitonin monitoring useful to modulate the extension of neck dissection in patients with medullary thyroid carcinoma?

BACKGROUND: The extension of the compartment-oriented neck dissection at primary surgery in medullary thyroid carcinoma (MTC) is controversial. Because a <50 % decrease in intraoperative calcitonin levels (IO-CT) after total thyroidectomy plus central neck dissection (TT-CND) has been associated with residual disease, IO-CT monitoring has been proposed to predict the completeness of surgery. The goal of the present prospective study was to verify the accuracy of IO-CT monitoring. METHODS: All patients scheduled for primary surgery for suspected or proven MTC between November 2010 and January 2013 were included. Calcitonin was measured pre-incision (basal level), after tumor manipulation, at the time TT-CND was accomplished (ablation level), 10 and 30 min after ablation. A decrease >50 % with respect to the highest IO-CT level 30 min after ablation was considered predictive of cure. RESULTS: Twenty-six patients were included, and IO-CT monitoring identified 18 of 23 cured patients (true negative results) and 2 of 3 patients with persistent disease (true positive result). In 5 patients with normal basal and stimulated postoperative calcitonin levels, a decrease <50 % was observed (false positive results). In one of three patients with persistent disease a >50 % decrease in IO-CT was observed (false negative results). Specificity, sensitivity, and accuracy of IO-CT were 78.2, 66.6, and 76.9 %, respectively. CONCLUSIONS: Intraoperative calcitonin monitoring is not highly accurate in predicting the completeness of surgical resection. In the present series, relying on IO-CT would result in limited resection in about one third of the patients with residual neck disease and in unnecessary lateral neck dissection in about 20 % of the cured patients.

Interstitial deletion of 3p22.3p22.2 encompassing ARPP21 and CLASP2 is a potential pathogenic factor for a syndromic form of intellectual disability: a co-morbidity model with additional copy number variations in a large family.

We describe a family in which four individuals (the mother and three children) presented with an overlapping phenotype of minor physical anomalies and intellectual disability. Four previously unreported copy number variants were found inherited either from the affected mother or from the healthy father, consisting of a 3p22.3p22.2 deletion (2.5 Mb), a 3p24.3 deletion (0.55 Mb), a 6q22.31 duplication (0.74 Mb), all maternally inherited, and an 18q11.2 duplication (0.276 Mb) which was paternally inherited. The deletions on chromosome 3 were both found to segregate with the disease. However, being the 0.55 Mb deleted segment on 3p24.3 devoid of genes, we considered that the 2.5 Mb deletion on 3p22.3p22.2 acts as major pathogenic rearrangement in this condition. Among the transcribed genes residing in this interval, ARPP21 and CLASP2 are proposed as good candidate genes on the basis of their functional properties. A co-morbidity role for the other small rearrangements detected in the affected individuals in association with the 3p22.3p22.2 deletion is also suggested, according to a second-side model of pathogenesis.

De Novo Partial 13q22-q34 Trisomy with Typical Neurological and Immunological Findings: A Case Report with New Genetic Insights.

The partial trisomy 13q encompasses an extensive variability of phenotypic and radiological findings including leukoencephalopathy and brain malformations such as holoprosencephaly, callosal dysgenesis, hippocampal hypoplasia, olfactory hypoplasia, and vermian hypoplasia. We report for the first time a case of a 23-year-old patient affected by de novo partial 13q22.1q34 trisomy (41.7 Mb, 72,365,975-114,077,122x3) presenting with hemiparesis related to both ischemic and haemorrhagic cerebral lesions compatible with cerebral vasculitis due to a possible combination of genetic and immunological interaction.

Morbidity from minimally invasive video-assisted thyroidectomy: a general review.

Minimally invasive video-assisted thyroidectomy (MIVAT) is known and used worldwide, it combines the advantages associated with endoscopic magnification with those due with traditional surgery. In selected patients, it should be considered a safe and valid alternative. Indeed, a lot of comparative studies have demonstrated the advantages of MIVAT in terms of low rate of complications, reduced postoperative pain, improved cosmetic results and higher patient satisfaction over traditional surgery. Anyway, for obtaining the best results, with similar or even less complication rate than traditional surgery, surgeons should be well trained, acquired confidence with a smaller surgical incision and with the use of endoscopic instruments.

Intraoperative high-dose calcium stimulation test in patients with sporadic medullary thyroid carcinoma is highly accurate in predicting lateral neck metastases.

BACKGROUND: Intraoperative measurement of calcitonin is not highly accurate in predicting the completeness of the operative resection after total thyroidectomy combined with central neck dissection (TT-CND) in patients with medullary thyroid carcinoma (MTC). We evaluated whether an intraoperative, high-dose calcium stimulation test (IO-CST) after TT-CND can predict lateral neck involvement. METHODS: Eleven patients who underwent primary operation for sporadic MTC were included. High-dose (25 mg/kg) calcium gluconate was administered after TT-CND with calcitonin measured at 2, 5, and 10 minutes after the calcium gluconate infusion. RESULTS: There were 2 males and 9 females (mean age, 51 years; range, 18-88). Three patients showed lateral neck metastases. At a mean follow-up of 7.0 months (range, 2-10), 1 patient showed distant metastases and 1 a slightly increased calcitonin level. After IO-CST, serum calcitonin increased in all the 3 patients with lateral neck metastases, and it remained unchanged or decreased in the other patients without lateral neck metastases. Percent variation of serum calcitonin after IO-CST was 92% in patients with lateral neck metastases and -3.1 ± 4.9% in patients without lateral neck metastases. CONCLUSION: Calcitonin measurement after IO-CST in patients with sporadic MTC can be highly accurate in predicting lateral neck nodes involvement. These results could represent a stimulus toward the development of a quick calcitonin assay.