No abstract

We have investigated the extent and pattern of immunostaining for ubiquitin protein (UBQ) in 60 patients with frontotemporal lobar degeneration (FTLD) with ubiquitin-positive, tau-negative inclusions (FTLD-U), 37 of whom were ascertained in Manchester UK and 23 in Newcastle-Upon-Tyne, UK. There were three distinct histological patterns according to the form and distribution of the UBQ pathology. Histological type 1 was present in 19 patients (32%) and characterised by the presence of a moderate number, or numerous, UBQ immunoreactive neurites and intraneuronal cytoplasmic inclusions within layer II of the frontal and temporal cerebral cortex, and cytoplasmic inclusions within granule cells of the dentate gyrus; neuronal intranuclear inclusions (NII) of a "cat's eye" or "lentiform" appearance were present in 17 of these patients. In histological type 2 (16 patients, 27%), UBQ neurites were predominantly, or exclusively, present with few intraneuronal cytoplasmic inclusions within layer II of the cerebral cortex, while in histological type 3 (25 patients, 42%), UBQ intraneuronal cytoplasmic inclusions either within the cortical layer II or in the granule cells of the dentate gyrus, with few or no UBQ neurites, were seen. In neither of these latter two groups were NII present. The inXuence of histological type on clinical phenotype was highly signiWcant with type 1 histology being associated clinically with cases of frontotemporal dementia (FTD) or progressive nonXuent aphasia (PNFA), type 2 histology with semantic dementia (SD), and type 3 histology with FTD, or FTD and motor neurone disease (MND).

We have investigated the extent and pattern of immunostaining for the TAR DNA-binding protein, TDP-43, in 37 patients with frontotemporal lobar degeneration with ubiquitin (UBQ) pathology (FTLD-U). We confirm that TDP-43 protein is a component of the UBQ immunoreactive (UBQ-ir) neuronal cytoplasmic inclusions (NCI), neuronal intranuclear inclusions (NII) and neurites of the cerebral cortex and hippocampus in FTLD-U. We further show that the same three histological patterns, previously identified by us according to the form, number and distribution of the UBQ-ir NCI, NII and neurites are equivalently present in TDP-43 immunohistochemistry. TDP-43 immunoreactive (TDP-43-ir) NCI with rounded, spicular or skein-type appearance were seen in motor neurones of the trigeminal or facial cranial nerve nuclei in one patient with frontotemporal dementia (FTD) and in the spinal cord in three patients with FTD + motor neurone disease (MND). In patients with MND alone, TDP-43-ir NCI are common in anterior horn cells of the spinal cord, and occasionally seen in neurones of the hypoglossus nucleus. We show that TDP-43-ir NCI are also present within neurones in the superior and inferior olives in FTLD-U, and in some patients with MND. Although TDP-43 is normally seen as a nuclear protein, nuclear TDP-ir was not observed in neurones of the cerebral cortex, brainstem and spinal cord in FTLD-U or MND when NCI were present. We conclude that the UBQ-ir lesions of FTLD and MND are defined by the presence of TDP-43, and that these disorders can be subsumed into a single disease entity under the umbrella of TDP-43 proteinopathy.

The 2011 PPA recommendations classify a large proportion of patients who meet basic PPA criteria. However, some patients had aphasic syndromes that could not be classified, suggesting that the 2011 recommendations do not cover the full range of PPA variants. Classification of semantic variant PPA provides a good prediction of underlying pathology. Classification of logopenic variant does not successfully differentiate PPA due to AD from PPA due to other pathologies.

One-third of all primary central nervous system tumors in adults are meningiomas. Rarely, meningiomas occur at multiple sites, usually occurring in individuals with type 2 neurofibromatosis (NF2). We sequenced the exomes of three unrelated individuals with familial multiple spinal meningiomas without NF2 mutations. We identified two individuals with heterozygous loss-of-function mutations in the SWI/SNF chromatin-remodeling complex subunit gene SMARCE1. Sequencing of SMARCE1 in six further individuals with spinal meningiomas identified two additional heterozygous loss-of-function mutations. Tumors from individuals with SMARCE1 mutations were of clear-cell histological subtype, and all had loss of SMARCE1 protein, consistent with a tumor suppressor mechanism. Our findings identify multiple-spinal-meningioma disease as a new discrete entity and establish a key role for the SWI/SNF complex in the pathogenesis of both meningiomas and tumors with clear-cell histology.

Two hundred and twenty-three consecutive patients fulfilling clinical diagnostic criteria for frontotemporal lobar degeneration (FTLD), and 259 patients with motor neuron disease (MND), for whom genomic DNA was available, were investigated for the presence of mutations in tau (MAPT) and progranulin (PGRN) genes. All FTLD patients had undergone longitudinal neuropsychological and clinical assessment, and in 44 cases, the diagnosis had been pathologically confirmed at post-mortem. Six different PGRN mutations were found in 13 (6%) patients with FTLD. Four apparently unrelated patients shared exon Q415X 10 stop codon mutation. However, genotyping data revealed all four patients shared common alleles of 15 SNPs from rs708386 to rs5848, defining a 45.8-kb haplotype containing the whole PGRN gene, suggesting they are related. Three patients shared exon 11 R493X stop codon mutation. Four patients shared exon 10 V452WfsX38 frameshift mutation. Two of these patients were siblings, though not apparently related to the other patients who in turn appeared unrelated. One patient had exon 1 C31LfsX34 frameshift mutation, one had exon 4 Q130SfsX130 frameshift mutation and one had exon 10 Q468X stop codon mutation. In addition, two non-synonymous changes were detected: G168S change in exon 5 was found in a single patient, with no family history, who showed a mixed FTLD/MND picture and A324T change in exon 9 was found in two cases; one case of frontotemporal dementia (FTD) with a sister with FTD+MND and the other in a case of progressive non-fluent aphasia (PNFA) without any apparent family history. MAPT mutations were found in 17 (8%) patients. One patient bore exon 10 + 13 splice mutation, and 16 patients bore exon 10 + 16 splice mutation. When PGRN and MAPT mutation carriers were excluded, there were no significant differences in either the allele or genotype frequencies, or haplotype frequencies, between the FTLD cohort as a whole, or for any clinical diagnostic FTLD subgroup, and 286 controls or between MND cases and controls. However, possession of the A allele of SNP rs9897526, in intron 4 of PGRN, delayed mean age at onset by approximately 4 years. Patients with PGRN and MAPT mutations did not differ significantly from other FTLD cases in terms of gender distribution or total duration of illness. However, a family history of dementia in a first-degree relative was invariably present in MAPT cases, but not always so in PGRN cases. Onset of illness was earlier in MAPT cases compared to PGRN and other FTLD cases. PNFA, combined with limb apraxia was significantly more common in PGRN mutation cases than other FTLD cases. By contrast, the behavioural disorder of FTD combined with semantic impairment was a strong predictor of MAPT mutations. These findings complement recent clinico-pathological findings in suggesting identifiable associations between clinical phenotype and genotype in FTLD.

We have investigated the pathological correlates of dementia in the brains from a consecutive series of 70 patients dying with a clinical diagnosis of frontotemporal lobar degeneration (FTLD). Clinical misdiagnosis rate was low with only 3 patients (4%) failing to show pathological changes consistent with this diagnosis; 1 patient had Alzheimer's disease and 2 had cerebrovascular disease (CVD). In the remaining 67 patients, the most common underlying histological cause was ubiquitin pathology with 24 (36%) cases so affected. In these, ubiquitin-positive inclusions were present in the cerebral cortex as small, rounded or crescent-shaped structures within the cytoplasm of neurones of layer II, together with coiled or curvilinear bodies within neurites, and in the hippocampus as small, solid and more spherical-shaped inclusion bodies within the cytoplasm of dentate gyrus granule cells. In one patient, "cat's eye" or "lentiform" intranuclear ubiquitin inclusions were also present. The second most common histological type was dementia lacking distinctive histology (DLDH), in which neither tau nor ubiquitin inclusions were present, with 16 cases (24%) being affected. Pick-type histology was seen in 14 cases (21%) and tau histological changes associated with frontotemporal dementia (FTD) linked to chromosome 17 (FTDP-17) were present in 11 cases (16%). One case (1%) showed an unusual tau pathology that could not be allocated to any of the other tau groups. Only 1 case (1%) had neuronal intermediate filament inclusion dementia. No cases with ubiquitinated, valosin-containing protein-immunoreactive intranuclear inclusion bodies of the type seen in inclusion body myopathy with Paget's disease of bone and frontotemporal dementia were seen. Clinicopathological correlation showed that any of these histological subtypes can be associated with FTD. However, for FTD with motor neurone disease (FTD+MND), semantic dementia or primary progressive aphasia (PA), the histological profile was either ubiquitin type or DLDH type; Pick-type histology was seen in only 1 case of PA. None of these latter three clinical subtypes was associated with a mutation in tau gene and FTDP-17 type of tau pathology. All cases of progressive apraxia were associated with Pick-type histology. Present data therefore indicate that, although ubiquitin pathology is the most common histological form associated with FTLD, this pathology is not tightly linked with, nor is pathologically diagnostic for, any particular clinical form of the disease, including FTD+MND.

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.