Background: Metastatic basal cell carcinoma (mBCC) is a very rare entity, and diagnosis can be challenging. Therapeutic options are limited, and response to targeted therapy is poor. Objective: To... Show moreBackground: Metastatic basal cell carcinoma (mBCC) is a very rare entity, and diagnosis can be challenging. Therapeutic options are limited, and response to targeted therapy is poor. Objective: To demonstrate a clonal relationship between BCCs and their metastases and to explore which hedgehog pathway-related mutations are involved in mBCC. Methods: Genetic analysis was conducted in 10 primary BCCs and their metastases. Genes relevant for BCC development were analyzed in tumor and metastasis material with small molecule molecular inversion probes (smMIPs) for PTCH1, PTCH2, SMO, SUFU, GLI2, and TP53 or with targeted next generation sequencing of the same genes and CDKN2A, CDKN2B, CIC, DAXX, DDX3X, FUBP1, NF1, NF2, PTEN, SETD2, TRAF7, and the TERT promoter. Results: In 8 of 10 patients, identical gene mutations could be demonstrated in the primary tumors and their metastases. A broad spectrum of mutations was found. Four patients had SMO mutations in their tumor or metastasis, or both. All SMO mutations found were known to cause resistance to targeted therapy with vismodegib. Limitations: In 2 patients there was insufficient qualitative DNA available for genetic analysis. Conclusions: Molecular testing can help to identify the origin of a BCC metastasis and may be of prognostic and therapeutic value. ( J Am Acad Dermatol 2021;85:1135-42.) Show less
Peeters, M.H.C.A.; Khan, M.; Rooijakkers, A.A.M.B.; Mulders, T.; Haer-Wigman, L.; Boon, C.J.F.; ... ; Collin, R.W.J. 2021
Mutations in PRPH2, encoding peripherin-2, are associated with the development of a wide variety of inherited retinal diseases (IRDs). To determine the causality of the many PRPH2 variants that... Show moreMutations in PRPH2, encoding peripherin-2, are associated with the development of a wide variety of inherited retinal diseases (IRDs). To determine the causality of the many PRPH2 variants that have been discovered over the last decades, we surveyed all published PRPH2 variants up to July 2020, describing 720 index patients that in total carried 245 unique variants. In addition, we identified seven novel PRPH2 variants in eight additional index patients. The pathogenicity of all variants was determined using the ACMG guidelines. With this, 107 variants were classified as pathogenic, 92 as likely pathogenic, one as benign, and two as likely benign. The remaining 50 variants were classified as variants of uncertain significance. Interestingly, of the total 252 PRPH2 variants, more than half (n = 137) were missense variants. All variants were uploaded into the Leiden Open source Variation and ClinVar databases. Our study underscores the need for experimental assays for variants of unknown significance to improve pathogenicity classification, which would allow us to better understand genotype-phenotype correlations, and in the long-term, hopefully also support the development of therapeutic strategies for patients with PRPH2-associated IRD. Show less
BackgroundHearing loss is one of the most prevalent disabilities worldwide, and has a significant impact on quality of life. The adult-onset type of the condition is highly heritable but the... Show moreBackgroundHearing loss is one of the most prevalent disabilities worldwide, and has a significant impact on quality of life. The adult-onset type of the condition is highly heritable but the genetic causes are largely unknown, which is in contrast to childhood-onset hearing loss.MethodsFamily and cohort studies included exome sequencing and characterisation of the hearing phenotype. Ex vivo protein expression addressed the functional effect of a DNA variant.ResultsAn in-frame deletion of 12 nucleotides in RIPOR2 was identified as a highly penetrant cause of adult-onset progressive hearing loss that segregated as an autosomal dominant trait in 12 families from the Netherlands. Hearing loss associated with the deletion in 63 subjects displayed variable audiometric characteristics and an average (SD) age of onset of 30.6 (14.9) years (range 0-70 years). A functional effect of the RIPOR2 variant was demonstrated by aberrant localisation of the mutant RIPOR2 in the stereocilia of cochlear hair cells and failure to rescue morphological defects in RIPOR2-deficient hair cells, in contrast to the wild-type protein. Strikingly, the RIPOR2 variant is present in 18 of 22 952 individuals not selected for hearing loss in the Southeast Netherlands.ConclusionCollectively, the presented data demonstrate that an inherited form of adult-onset hearing loss is relatively common, with potentially thousands of individuals at risk in the Netherlands and beyond, which makes it an attractive target for developing a (genetic) therapy. Show less
Background: Given the rapid evolution in the management of soft tissue sarcoma (STS), it is essential to revisit the evidence regularly. This review examines topics of interest for early management... Show moreBackground: Given the rapid evolution in the management of soft tissue sarcoma (STS), it is essential to revisit the evidence regularly. This review examines topics of interest for early management of STS: the impact of molecular genetics on sarcoma classification; the importance of a correct diagnosis and strategy in the surgical management of STS; current status on use of radiotherapy in STS. Areas covered: Accurate diagnosis of STS combines histomorphology, immunochemistry, and molecular genetics, although morphology is the mainstay of therapeutic planning. As diagnosis of STS is challenging, it is best conducted within a multidisciplinary environment. Expert surgery in STS takes into account multiple parameters including biopsy, imaging, pathological knowledge, technical issues, and a multidisciplinary approach. The sum of these factors informs decisions about whether or not to perform surgery and the choice of surgical technique. Advances in radiotherapy are challenging the paradigm of applying the same dose and treatment schedule to all STS patients irrespective of subtype. Preoperative radiotherapy of specific histotypes appears to be the future although more research is required to address uncertainties such as fraction size, total dose, combined modality regimens, and individual sensitivity to radiotherapy. Expert opinion: STS should be managed in a reference center. Show less
Fanoni, D.; Corti, L.; Alberti-Violetti, S.; Tensen, C.P.; Venegoni, L.; Vermeer, M.; ... ; Berti, E. 2018
