The SETX missense variation spectrum as evaluated in patients with ALS4-like motor neuron diseases.

Mutations in the senataxin (SETX) gene can cause amyotrophic lateral sclerosis 4 (ALS4), an autosomal dominant form of juvenile onset amyotrophic lateral sclerosis, or result in autosomal recessive ataxia with oculomotor apraxia type 2. Great caution regarding the possible disease causation, especially of missense variations, has to be taken. Here, we evaluated the significance of all previously reported SETX missense mutations as well as six newly identified variations in 54 patients suspected of having ALS4. Yet, epidemiologic and in silico evidence indicates that all newly identified variations and two previously published ALS4-related missense variations (C1554G and I2547T) are most likely non-pathogenic, demonstrating the problems of interpretation of SETX missense alleles in the absence of functional assays.

The dynactin p150 subunit: cell biology studies of sequence changes found in ALS/MND and Parkinsonian syndromes.

The dynactin p150glued subunit, encoded by the gene DCTN1 is part of the dynein-dynactin motor protein complex responsible for retrograde axonal transport. This subunit is a candidate modifier for neurodegenerative diseases, in particular motoneuron and extrapyramidal diseases. Based on an extensive screening effort of all 32 exons in more than 2,500 ALS/MND patients, patients suffering from Parkinsonian Syndromes and controls, we investigated 24 sequence variants of p150 in cell-based studies. We used both non-neuronal cell lines and primary rodent spinal motoneurons and report on cell biological abnormalities in five of these sequence alterations and also briefly report on the clinical features. Our results suggest the presence of biological changes caused by some p150 mutants pointing to a potential pathogenetic significance as modifier of the phenotype of the human disease.

Case report: Early-onset Parkinson's disease with initial spastic paraparesis and hyperreflexia caused by compound heterozygous PRKN-gene exon 2 and 4 deletions.

Pathogenic variants in the Parkin-gene (PRKN) are among the most common genetic causes of early onset Parkinson's disease (EOPD). Patients with EOPD can present with atypical clinical features and misdiagnosis is frequent. Here, we report a clinical phenotype with atypical signs and symptoms of a 35-year-old male patient with EOPD caused by a compound heterozygous PRKN-gene deletion of exons 2 and 4. After the initial diagnosis of stiff person syndrome, the patient was admitted to our department for a second opinion after 8 years of untreated disease progression. The patient presented with prominent spastic paraparesis pronounced on the right side and hyperreflexia as well as Parkinsonism with rigidity predominantly affecting the upper limbs, bradykinesia, and resting tremor. In the diagnostic assessment, magnetic evoked potentials to the anterior tibial muscles showed a low amplitude on the right side, compatible with pyramidal tract disturbance. However, an MRI of the head and the spine did not show any pathologies or atrophy. A [123I] FP-CIT SPECT scan revealed profoundly and left-pronounced reduced striatal uptake suggesting a neurodegenerative Parkinson's syndrome. Even though an acute levodopa challenge did not show marked improvement of symptoms, the chronic levodopa challenge with up to 450 mg/day significantly reduced the rigidity and bradykinesia. Surprisingly, spastic paraparesis and hyperreflexia diminished under dopaminergic treatment. Finally, genetic analysis by next-generation sequencing via copy number variant analysis (CNV) and multiplex ligation-dependent probe amplification (MLPA) confirmed compound heterozygous deletions of exons 2 and 4 in the PRKN-gene. As presented in this case, the awareness of atypical clinical symptoms of EOPD is essential to prevent misdiagnosis in young patients.

Phenotypic spectrum in recessive STING-associated vasculopathy with onset in infancy: Four novel cases and analysis of previously reported cases.

Gain-of-function variants in the stimulator of interferon response cGAMP interactor 1 (STING1) gene cause STING-Associated Vasculopathy with onset in Infancy (SAVI). Previously, only heterozygous and mostly de novo STING1 variants have been reported to cause SAVI. Interestingly, one variant that only leads to SAVI when homozygous, namely c.841C>T p.(Arg281Trp), has recently been described. However, there are no entries in public databases regarding an autosomal recessive pattern of inheritance. Here, we report four additional unrelated SAVI patients carrying c.841C>T in homozygous state. All patients had interstitial lung disease and displayed typical interferon activation patterns. Only one child displayed cutaneous vasculitis, while three other patients presented with a relatively mild SAVI phenotype. Steroid and baricitinib treatment had a mitigating effect on the disease phenotype in two cases, but failed to halt disease progression. Heterozygous c.841C>T carriers in our analysis were healthy and showed normal interferon activation. Literature review identified eight additional cases with autosomal recessive SAVI caused by c.841C>T homozygosity. In summary, we present four novel and eight historic cases of autosomal recessive SAVI. We provide comprehensive clinical data and show treatment regimens and clinical responses. To date, SAVI has been listed as an exclusively autosomal dominant inherited trait in relevant databases. With this report, we aim to raise awareness for autosomal recessive inheritance in this rare, severe disease which may aid in early diagnosis and development of optimized treatment strategies.

An unusual presentation of Huntington's disease.

We describe the case of a 59-year-old woman who exhibited psychotic symptoms, cognitive dysfunction, and restlessness. While the clinical picture and 18F-FDG PET/CT suggested the presence of a tauopathy, especially frontotemporal dementia or progressive supranuclear palsy, genetic testing eventually revealed Huntington's disease.

Concentrations of beta-amyloid precursor protein processing products in cerebrospinal fluid of patients with amyotrophic lateral sclerosis and frontotemporal lobar degeneration.

Frontotemporal lobar degeneration (FTLD) and amyotrophic lateral sclerosis (ALS) are neurodegenerative disorders with heterogeneous clinical presentation but common neuropathological characteristics and pathophysiological substrates, which led to the view of ALS and FTLD representing two manifestations of a clinicopathological spectrum. For both diseases, changes in metabolism of beta-amyloid precursor protein (APP) are reported. In a pilot study, we analyzed cerebrospinal fluid from patients of the ALS-FTLD spectrum for APP processing products. ALS patients show elevated absolute levels of soluble APP and a shift towards the nonamyloidogenic APP processing pathway in contrast to patients with FTLD or ALS + FTLD. Changes in Abeta pattern could be described, allowing separation of patients with pure FTLD from ALS + FTLD. Combination of sAPP and Abeta values improves group differentiation. These findings may provide information on pathophysiological processes in the ALS-FTLD disease spectrum and could have impact in neurochemical diagnosis. We propose to expand this study to larger patient groups comprising followed up cases with known neuropathology.

Proteome analysis reveals candidate markers of disease progression in amyotrophic lateral sclerosis (ALS).

OBJECTIVES: In amyotrophic lateral sclerosis (ALS) the pathological determinants of disease progression remain poorly understood. We aimed to identify a characteristic CSF protein pattern that could provide new candidate biomarkers of disease progression in ALS. METHODS: Using the two-dimensional difference in gel electrophoresis (2-D-DIGE), we compared CSF samples from patients with ALS that showed a rapid progression of disease (ALS-rp, n=9) over a follow-up time of 2 years and from patients with ALS that showed a slow progression of disease over follow-up (ALS-sl, n=9) over the same period. Protein spots that showed significant differences between patients and controls were selected for further analysis by MALDI-TOF mass spectrometry. For validation of identified spots ELISA and nephelometry were performed for two candidate proteins on a second cohort of patients (n=40). RESULTS: We identified 6 different proteins and their isoforms which were all upregulated in ALS-rp as compared to ALS-sl (heat shock protein1, alpha-1 antitrypsin, fetuin-A precursor, transferrin, transthyretin (TTR), nebulin-related anchoring protein). For Fetuin-A and TTR, our findings could be confirmed by quantitative assay. CONCLUSIONS: Fetuin-A and TTR are promising candidate markers for disease progression in ALS that warrant further evaluation on a larger cohort of patients.

MMP-2 and MMP-9 are elevated in spinal cord and skin in a mouse model of ALS.

We aimed to clarify the role of matrix metalloproteinases (MMP) as a possible link between neurodegeneration and skin pathology in ALS by determination of gelatinase MMP-2 and MMP-9 in spinal cord and skin of transgenic SOD1((G93A)) mice. To elucidate mechanisms influencing MMPs, markers of oxidative damage (malondialdehyde (MDA), 3-nitrotyrosine (3-NT) and 8-hydroxy-2'-deoxyguanosine (8OH2'dG)) as well as cytokines (tumor necrosis factor alpha (TNF-alpha) and interleukin 1ss (IL-1ss)) were determined. We measured MMP-9, MMP-2, 3-NT, TNF-alpha, and IL-1ss using ELISA, MDA using High Performance Liquid Chromatography (HPLC) and 8OH2'dG using HPLC with electrochemical detection (HPLC-ECD) in SOD1 and WT. MMP-9 was elevated in spinal cord and skin of SOD1 at 90 days (p=0.009, p<0.001) and 120 days (p<0.01, p=0.04). MMP-2 was elevated in the spinal cord at 90 days (p=0.01) and in the skin at 120 days (p=0.039). We observed a correlation of MMP-9 in spinal cord and skin of SOD1 (p=0.04). MDA was elevated in the spinal cord of SOD1 at 90 and 120 days (p=0.00006, p=0.01) and 8OH2'dG at 90 days (p=0.048). IL-1ss was elevated in the spinal cord of SOD1 at 120 days (p=0.02). Our data confirms that gelatinase MMPs are a common factor linking neurodegeneration and skin changes in ALS. It suggests that oxidative stress and microglial-derived cytokines contribute to the elevation of gelatinase MMPs especially in later stages of disease. Our data raises the question whether the skin may function as a biomarker for specific aspects of disease pathology in ALS.

Linking neuron and skin: matrix metalloproteinases in amyotrophic lateral sclerosis (ALS).

Amyotrophic lateral sclerosis (ALS) mainly affects the motor neurons but may also include other organs such as the skin. We aimed to determine whether matrix metalloproteinases could provide a link between neuronal degeneration and skin alterations in ALS. We measured CSF, serum and skin tissue MMP-2 and MMP-9 using ELISA and malondialdehyde (MDA), a marker of lipid peroxidation, using High Performance Liquid Chromatography (HPLC) in 54 ALS patients and 36 controls. We found CSF and skin MMP-9 to be elevated in ALS as compared to controls (p<0.001, p=0.03, respectively). We observed CSF MMP-9 to be highest in patients with a rapid progressive course of disease (p=0.008). In contrast, we found no significant differences of CSF, serum or skin concentrations of MMP-2 as compared to controls. CSF MMP-2 concentrations decreased with duration of disease (p=0.04, R=-0.31). MDA was elevated in serum of ALS (p<0.001), though no correlation with MMP-2 or MMP-9 was observed. Our findings indicate a general upregulation of MMP-9 in ALS. MMP-9 seems to play a role in both neurodegeneration and skin changes in ALS and could thus be a common factor linking otherwise distant aspects of disease pathology.

Genome-wide association study identifies 19p13.3 (UNC13A) and 9p21.2 as susceptibility loci for sporadic amyotrophic lateral sclerosis.

We conducted a genome-wide association study among 2,323 individuals with sporadic amyotrophic lateral sclerosis (ALS) and 9,013 control subjects and evaluated all SNPs with P < 1.0 x 10(-4) in a second, independent cohort of 2,532 affected individuals and 5,940 controls. Analysis of the genome-wide data revealed genome-wide significance for one SNP, rs12608932, with P = 1.30 x 10(-9). This SNP showed robust replication in the second cohort (P = 1.86 x 10(-6)), and a combined analysis over the two stages yielded P = 2.53 x 10(-14). The rs12608932 SNP is located at 19p13.3 and maps to a haplotype block within the boundaries of UNC13A, which regulates the release of neurotransmitters such as glutamate at neuromuscular synapses. Follow-up of additional SNPs showed genome-wide significance for two further SNPs (rs2814707, with P = 7.45 x 10(-9), and rs3849942, with P = 1.01 x 10(-8)) in the combined analysis of both stages. These SNPs are located at chromosome 9p21.2, in a linkage region for familial ALS with frontotemporal dementia found previously in several large pedigrees.

TDP-43 in cerebrospinal fluid of patients with frontotemporal lobar degeneration and amyotrophic lateral sclerosis.

BACKGROUND: Recently, TAR DNA-binding protein 43 (TDP-43) was identified as the major component of ubiquitin-positive tau-negative neuronal and glial inclusions in the most common form of frontotemporal lobar degeneration (FTLD) and in amyotrophic lateral sclerosis (ALS). It was demonstrated that different TDP-43 profiles correspond to clinical phenotypes of FTLD or ALS subgroups, and the differential diagnostic potential of TDP-43 was suggested. OBJECTIVES: To examine TDP-43 in cerebrospinal fluid (CSF) and to analyze whether it could serve as a diagnostic marker. DESIGN: We characterized CSF TDP-43 by immunoblot using different TDP-43 antibodies and determined the relative TDP-43 levels in CSF samples from patients. SETTING: Academic research. PATIENTS: Twelve patients with FTLD, 15 patients with ALS, 9 patients with ALS plus FTLD, 3 patients with ALS plus additional signs of frontal disinhibition, and 13 control subjects. MAIN OUTCOME MEASURES: Results of TDP-43 immunoblot. RESULTS: Polyclonal TDP-43 antibodies recognized a 45-kDa band in all analyzed samples. Two monoclonal and N-terminus-specific antibodies did not detect any specific bands, but C-terminus-specific antibodies detected a 45-kDa band and additional bands at approximately 20 kDa in all CSF samples. Relative quantification of 45-kDa bands revealed significant differences among the diagnostic groups (P =.046). Specifically, patients with ALS (P =.03) and FTLD (P =.02) had higher TDP-43 levels than controls but with a prominent overlap of values. CONCLUSION: Although there is no evidence of pathologically altered TDP-43 proteins in CSF, TDP-43 levels in CSF might aid in characterizing subgroups of patients across the ALS and FTLD disease spectrum.