We recently reported SMARCE1 mutations as a cause of spinal clear cell meningiomas. Here, we have identified five further cases with non-NF2 spinal meningiomas and six with non-NF2 cranial meningiomas. Three of the spinal cases and three of the cranial cases were clear cell tumours. We screened them for SMARCE1 mutations and investigated copy number changes in all point mutation-negative samples. We identified two novel mutations in individuals with spinal clear cell meningiomas and three mutations in individuals with cranial clear cell meningiomas. Copy number analysis identified a large deletion of the 5' end of SMARCE1 in two unrelated probands with spinal clear cell meningiomas. Testing of affected and unaffected relatives of one of these individuals identified the same deletion in two affected female siblings and their unaffected father, providing further evidence of incomplete penetrance of meningioma disease in males. In addition, we found loss of SMARCE1 protein in three of 10 paraffin-embedded cranial clear cell meningiomas. Together, these results demonstrate that loss of SMARCE1 is relevant to cranial as well as spinal meningiomas. Our study broadens the spectrum of mutations in the SMARCE1 gene and expands the phenotype to include cranial clear cell meningiomas.

No abstract

Hereditary spastic paraplegias (HSPs) are clinically and genetically heterogeneous neurodegenerative disorders. Numerous genes linked to HSPs, overlapping phenotypes between HSP subtypes and other neurodegenerative disorders and the HSPs’ dual mode of inheritance (both dominant and recessive) make the genetic diagnosis of HSPs complex and difficult. Out of the original HSP cohort comprising 306 index cases (familial and isolated) who had been tested according to “traditional workflow/guidelines” by Multiplex Ligation-dependent Probe Amplification (MLPA) and Sanger sequencing, 30 unrelated patients (all familial cases) with unsolved genetic diagnoses were tested using next-generation sequencing (NGS). One hundred thirty-two genes associated with spastic paraplegias, hereditary ataxias and related movement disorders were analysed using the Illumina TruSight™ One Sequencing Panel. The targeted NGS data showed pathogenic variants, likely pathogenic variants and those of uncertain significance (VUS) in the following genes: SPAST (spastin, SPG4), ATL1 (atlastin 1, SPG3), WASHC5 (SPG8), KIF5A (SPG10), KIF1A (SPG30), SPG11 (spatacsin), CYP27A1, SETX and ITPR1. Out of the nine genes mentioned above, three have not been directly associated with the HSP phenotype to date. Considering the phenotypic overlap and joint cellular pathways of the HSP, spinocerebellar ataxia (SCA) and amyotrophic lateral sclerosis (ALS) genes, our findings provide further evidence that common genetic testing may improve the diagnostics of movement disorders with a spectrum of ataxia-spasticity signs.Electronic supplementary materialThe online version of this article (10.1007/s10048-019-00565-6) contains supplementary material, which is available to authorized users.

Biallelic loss-of-function mutations in SPG11 cause a wide spectrum of recessively inherited, neurodegenerative disorders including hereditary spastic paraplegia (HSP), amyotrophic lateral sclerosis, and Charcot-Marie-Tooth disease. By comprehensive screening of three large cohorts of HSP index patients, we identified 83 alleles with "small" mutations and 13 alleles that carry large genomic rearrangements. Including relevant data from previous studies, we estimate that copy number variants (CNVs) account for ∼19% of pathogenic SPG11 alleles. The breakpoints for all novel and some previously reported CNVs were determined by long-range PCR and sequencing. This revealed several Alu-associated recombination hotspots. We also found evidence for additional mutational mechanisms, including for a two-step event in which an Alu retrotransposition preceded the actual rearrangement. Apparently independent samples with identical breakpoints were analyzed by microsatellite PCRs. The resulting haplotypes suggested the existence of two rearrangement founder alleles. Our findings widen the spectra of mutations and mutational mechanisms in SPG11, underscore the pivotal role played by Alus, and are of high diagnostic relevance for a wide spectrum of clinical phenotypes including the most frequent form of recessive HSP.

No abstract

BackgroundHereditary ataxias (HA) are a rare group of heterogeneous disorders. Here, we present results of molecular testing a group of ataxia patients using custom-designed Next Generation Sequencing (NGS) panel. Due to genetic and clinical overlapping of hereditary ataxias and spastic paraplegias (HSP), designed panel encompassing together HA and HSP genes. MethodsThe NGS libraries comprising coding sequence for 152 genes were performed using KAPA HyperPlus and HyperCap Target Enrichment Kit and sequenced on the MiSeq instrument. Obtained results were analyzed using BaseSpace Variant Interpreter and Integrative Genomics Viewer. All pathogenic and likely pathogenic variants were con rmed using the Sanger sequencing. ResultsA total of 29 patients with hereditary ataxias were enrolled to the NGS testing, and 16 patients had a con rmed molecular diagnosis with diagnostic e ciency of 55.2%. Pathogenic or likely pathogenic mutations were identi ed in 10 different genes:

Hereditary Spastic Paraplegias (HSP) are heterogenic neurodegenerative disorders with progressive spasticity of the lower limbs as a prominent feature. Spastic paraplegia type 6 (SPG6) is an autosomal dominant form of the disorder caused by point mutations in the NIPA1 gene on chromosome 15q11.2. The microdeletions within the region 15q11.2 spanning the four genes TUBGCP5, CYFIP1, NIPA2, and NIPA1 were previously reported in several different syndromes, including mental retardation, and/or developmental delay with hypotonia. Furthermore, these genes were associated with several congenital abnormalities, including autism, developmental delay, motor, and language disturbances, behavioural problems, and Idiopathic General Epilepsies (IGE), suggesting the existence of a new microdeletion syndrome. Our index cases, in whom the microdeletion 15q11.2 was detected, suffer from spastic paraplegia, but neither cognitive impairment nor behavioural problems were observed in them and other tested relatives. We considered several interpretations of the 15q11.2 microdeletion's phenotypic significance, including polymorphism, the pleiotropic effect of the microdeletion, and the influence of other modifiers. Specifying the exact range of the microdeletion 15q11.2 in patients with diverse clinical presentation is essential. Though the clinical implications of the microdeletion 15q11.2 remain unclear, our study contributes by extending the phenotypic variability of the subjects carrying this microrearrangement.

Introduction. The expansion of a hexanucleotide GGGGCC repeat (G 4 C 2 ) in the C9orf72 locus is the most common genetic cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). In addition, C9orf72 expansion has also been detected in patients with a clinical manifestation of Parkinson's Disease (PD), Alzheimer's Disease (AD), Huntington's Disease (HD), and ataxic disorders. Material and methods.A total of 1,387 patients with clinically suspected ALS, HD or spinal and bulbar muscular atrophy (SBMA) were enrolled, and the prevalence of C9orf72 expansions was estimated.Results. The hexanucleotide expansion accounted for 3.7% of the ALS patients, 0.2% of the HD suspected patients with excluded HTT mutation, and 1.3% of the suspected SBMA patients with excluded mutation in AR gene.Conclusions: This is the first report revealing the presence of C9orf72 expansion in patients with a suspected SBMA diagnosis. Consequently, we advise testing for C9orf72 expansion in patients presenting with the SBMA phenotype and a genetically unsolved diagnosis.