Intragenic inversions in NF1 gene as pathogenic mechanism in neurofibromatosis type 1.

Neurofibromatosis type 1 (NF1), an autosomal dominant disorder characterized by skin pigmentary lesions and multiple cutaneous neurofibromas, is caused by neurofibromin 1 (NF1) loss of function variants. Currently, a molecular diagnosis is frequently established using a multistep protocol based on cDNA and gDNA sequence analysis and/or Multiplex Ligation-dependent Probe Amplification (MLPA) assay on genomic DNA, providing an overall detection rate of about 95-97%. The small proportion of clinically diagnosed patients, which at present do not obtain a molecular confirmation likely are mosaic, as their pathogenic variant may remain undetected due to low sensitivity of low coverage NGS approaches, or they may carry a type of pathogenic variant refractory to currently used technologies. Here, we report two unrelated patients presenting with two different inversions that disrupt the NF1 coding sequence, resulting in an NF1 phenotype. In one subject, the inversion was associated with microdeletions spanning a few NF1 exons at both breakpoints, while in the other the rearrangement did not cause exon loss, thus testing negative by MLPA assay. Considering the high proportion of repeated regions within the NF1 sequence, we propose that intragenic structural rearrangements should be considered as possible pathogenic mechanisms in patients fulfilling the NIH diagnostic criteria of NF1 but lacking of molecular confirmation and in patients with NF1 intragenic microdeletions.

A ZFHX4 mutation associated with a recognizable neuropsychological and facial phenotype.

Several patients with chromosomal deletions including ZFHX4 gene have been described, whereas point mutations are very rare. This gene encodes for a transcription factor involved in the development of several embryonal processes, including brain differentiation. Patients with 8q21.11 deletions usually show intellectual disability, short stature, peculiar facial features, and severe eye abnormalities. We describe a female patient with mild intellectual disability, autism spectrum disorder, strabismus, ptosis, low-set and prominent ears, high-arched palate, microretrognathia. Clinical Exome Sequencing revealed the presence of a de novo heterozygous variant in ZFHX4. Therefore, we further investigate the different phenotypes of ZFHX4 mutations and 8q21.11 deletions.

Noninvasive In Vivo Imaging and Biologic Characterization of Thyroid Tumors by ImmunoPET Targeting of Galectin-3.

The high prevalence of thyroid nodules in the adult population and the relatively low incidence of thyroid cancer make the preoperative identification of malignant lesions challenging. The ß-galactoside-binding protein galectin-3 is widely expressed in well-differentiated thyroid carcinomas, but not in normal thyrocytes and benign thyroid nodules. This molecule offers a candidate biomarker to improve thyroid cancer diagnosis. Here we report the development of an immunoPET approach for noninvasive imaging of thyroid cancer. The method employs a (89)Zr-labeled mAb to galectin-3, which shows high specificity and binding affinity in vitro Reliable and specific immunoPET imaging was obtained of thyroid cancer in vivo in murine xenograft models of human thyroid cancer. Our findings provide a method to improve the clinical management of patients with thyroid nodules while reducing unnecessary surgery and social costs. Cancer Res; 76(12); 3583-92. ©2016 AACR.