Hexanucleotide repeat expansion in SCA36 reduces the expression of genes involved in ribosome biosynthesis and protein translation.

Hereditary spinocerebellar ataxia (SCA) is a group of clinically and genetically heterogeneous inherited disorders characterized by slowly progressive cerebellar ataxia. We ascertained a Japanese pedigree with autosomal dominant SCA comprising four family members, including two patients. We identified a GGCCTG repeat expansion of intron 1 in the NOP56 gene by Southern blotting, resulting in a molecular diagnosis of SCA36. RNA sequencing using peripheral blood revealed that the expression of genes involved in ribosomal organization and translation was decreased in patients carrying the GGCCTG repeat expansion. Genes involved in pathways associated with ribosomal organization and translation were enriched and differentially expressed in the patients. We propose a novel hypothesis that the GGCCTG repeat expansion contributes to the pathogenesis of SCA36 by causing a global disruption of translation resulting from ribosomal dysfunction.

Ingestion of a collagen peptide containing high concentrations of prolyl-hydroxyproline and hydroxyprolyl-glycine reduces advanced glycation end products levels in the skin and subcutaneous blood vessel walls: a randomized, double-blind, placebo-controlled study.

In this randomized, double-blind, placebo-controlled study, we investigated the effects of collagen peptides (CP) containing high concentrations of prolyl-hydroxyproline and hydroxyprolyl-glycine on advanced glycation end products (AGEs) levels in the skin and subcutaneous blood vessel walls. A total of 31 individuals aged 47-87 years were randomly assigned to receive either 5 g/day of fish-derived CP or a placebo for 12 weeks. Body and blood compositions and AGEs levels were measured at the beginning and end of the study. No adverse events were observed, and both groups' blood and body compositions did not change significantly. However, the CP group had significantly lower AGEs levels and a slightly lower insulin resistance index (homeostasis model assessment ratio [HOMA-R]) than the placebo group. In addition, the percentage changes in AGEs and HOMA-R levels were positively and strongly correlated in both groups. These findings suggest that fish-derived CP may be effective in reducing AGEs levels and improving insulin resistance.

Familial paroxysmal kinesigenic dyskinesia with a novel missense variant (Arg2866Trp) in NBEA.

Paroxysmal kinesigenic dyskinesia (PKD) is a movement disorder characterized by episodic involuntary movement attacks triggered by sudden movements, acceleration, or intention to move. We ascertained two Japanese familial cases with PKD. The proband is a 22-year-old woman who had noted sudden brief (<30 s) of involuntary movements provoked by kinesigenic trigger such as starting to run, getting on a train, picking up a telephone receiver and so on at the age of 14. Interictal brain single photon emission computed tomography (SPECT) showed hyperperfusion in the left thalamus. A 46-year-old woman, the mother of the proband was also suffering from brief attacks triggered by starting to run in her high school days. On neurological examination, both showed no abnormality. Whole exome sequencing combined with rigorous filtering revealed two heterozygous nonsynonymous variants (NM_001447: c.8976G > C [p.Gln2992His] in FAT2 and NM_015678: c.8596C > T [p.Arg2866Trp] in NBEA). Real time quantitative PCR analysis of Nbea mRNA levels in the developing rat brain revealed peak at postnatal day 28 and decline at postnatal day 56. This result might match the most common clinical course of PKD from the point of view of the most common age at remission. NBEA has been reported to be responsible for neurodevelopmental disease accompanied by epilepsy. We concluded the variant in NBEA most likely to be responsible for our familial cases of PKD.

Intronic variant in IQGAP3 associated with hereditary neuropathy with proximal lower dominancy, urinary disturbance, and paroxysmal dry cough.

In 2008, we reported a clinically and genetically new type of autosomal dominant disorder of motor and sensory neuropathy with proximal dominancy in the lower extremities, urinary disturbance, and paroxysmal dry cough. To identify the nucleotide variant causative of this disease, we reanalyzed the linkage of the original Japanese pedigree including seven newly ascertained subjects with updated information. We assigned the locus of the disease to 1p13.3-q23 (maximum logarithm-of-odds score = 2.71). Exome sequencing for five patients and one healthy relative from the pedigree revealed 2526 patient-specific single-nucleotide variants (SNVs). By rigorous filtering processes using public databases, our linkage results, and functional prediction, followed by Sanger sequencing of the pedigree and 520 healthy Japanese individuals, we identified an intronic SNV in IQGAP3, a gene known to be associated with neurite outgrowth. Upon pathological examination of the sural nerve, moderate, chronic, mainly axonal neuropathy was observed. By histochemical analyses, we observed a patient-specific increase of IQGAP3 expression in the sural nerve. We concluded that the variant of IQGAP3 is associated with the disease in our pedigree.

Genetic variants and cellular stressors associated with exfoliation syndrome modulate promoter activity of a lncRNA within the LOXL1 locus.

Exfoliation syndrome (XFS) is a common, age-related, systemic fibrillinopathy. It greatly increases risk of exfoliation glaucoma (XFG), a major worldwide cause of irreversible blindness. Coding variants in the lysyl oxidase-like 1 (LOXL1) gene are strongly associated with XFS in all studied populations, but a functional role for these variants has not been established. To identify additional candidate functional variants, we sequenced the entire LOXL1 genomic locus (∼40 kb) in 50 indigenous, black South African XFS cases and 50 matched controls. The variants with the strongest evidence of association were located in a well-defined 7-kb region bounded by the 3'-end of exon 1 and the adjacent region of intron 1 of LOXL1. We replicated this finding in US Caucasian (91 cases/1031 controls), German (771 cases/1365 controls) and Japanese (1484 cases/1188 controls) populations. The region of peak association lies upstream of LOXL1-AS1, a long non-coding RNA (lncRNA) encoded on the opposite strand of LOXL1. We show that this region contains a promoter and, importantly, that the strongly associated XFS risk alleles in the South African population are functional variants that significantly modulate the activity of this promoter. LOXL1-AS1 expression is also significantly altered in response to oxidative stress in human lens epithelial cells and in response to cyclic mechanical stress in human Schlemm's canal endothelial cells. Taken together, these findings support a functional role for the LOXL1-AS1 lncRNA in cellular stress response and suggest that dysregulation of its expression by genetic risk variants plays a key role in XFS pathogenesis.

Episodic ataxia type 2 with a novel missense variant (Leu602Arg) in CACNA1A.

Autosomal dominant episodic ataxia type 2 (EA2) is caused by variants in CACNA1A. We examined a 20-year-old male with EA symptoms from a Japanese family with hereditary EA. Cerebellar atrophy was not evident, but single photon emission computed tomography showed cerebellar hypoperfusion. We identified a novel nonsynonymous variant in CACNA1A, NM_001127222.2:c.1805T>G (p.Leu602Arg), which is predicted to be functionally deleterious; therefore, this variant is likely responsible for EA2 in this pedigree.

A trial of topiramate for patients with hereditary spinocerebellar ataxia.

In an open pilot trial, six patients with various hereditary forms of spinocerebellar ataxia (SCA) were assigned to topiramate (50 mg/day) for 24 weeks. Four patients completed the protocol without adverse events. Of these four patients, topiramate was effective for three patients. Some patients with SCA could respond to treatment with topiramate.

Oleic Acid-Containing Phosphatidylinositol Is a Blood Biomarker Candidate for SPG28.

Hereditary spastic paraplegia is a genetic neurological disorder characterized by spasticity of the lower limbs, and spastic paraplegia type 28 is one of its subtypes. Spastic paraplegia type 28 is a hereditary neurogenerative disorder with an autosomal recessive inheritance caused by loss of function of DDHD1. DDHD1 encodes phospholipase A1, which catalyzes phospholipids to lysophospholipids such as phosphatidic acids and phosphatidylinositols to lysophosphatidic acids and lysophoshatidylinositols. Quantitative changes in these phospholipids can be key to the pathogenesis of SPG28, even at subclinical levels. By lipidome analysis using plasma from mice, we globally examined phospholipids to identify molecules showing significant quantitative changes in Ddhd1 knockout mice. We then examined reproducibility of the quantitative changes in human sera including SPG28 patients. We identified nine kinds of phosphatidylinositols that show significant increases in Ddhd1 knockout mice. Of these, four kinds of phosphatidylinositols replicated the highest level in the SPG28 patient serum. All four kinds of phosphatidylinositols contained oleic acid. This observation suggests that the amount of oleic acid-containing PI was affected by loss of function of DDHD1. Our results also propose the possibility of using oleic acid-containing PI as a blood biomarker for SPG28.

Case report: Frontotemporal dementia and amyotrophic lateral sclerosis caused by a missense variant (p.Arg89Trp) in the valosin-containing protein gene.

Frontotemporal dementia and/or amyotrophic lateral sclerosis 6, also known as amyotrophic lateral sclerosis 14, is an autosomal dominant, progressive neurodegenerative disorder caused by various mutations in the valosin-containing protein gene. In this report, we examined a 51-year-old female Japanese patient with frontotemporal dementia and amyotrophic lateral sclerosis. The patient began noticing gait disturbances at the age of 45 years. Neurological examination at the age of 46 years met the Awaji criteria for clinically probable amyotrophic lateral sclerosis. At the age of 49 years, she tended to have poor mood and an aversion to activity. Her symptoms gradually worsened. She required a wheelchair for transport and had difficulty communicating with others because of poor comprehension. She then began to frequently exhibit irritability. Eventually, she was admitted to the psychiatric hospital because uncontrollable violent behavior throughout the day. Longitudinal brain magnetic resonance imaging revealed progressive brain atrophy with temporal dominance, non-progressive cerebellar atrophy, and some non-specific white matter intensities. Brain single photon emission computed tomography showed hypoperfusion in the bilateral temporal lobes and cerebellar hemispheres. Clinical exome sequencing revealed the presence of a heterozygous nonsynonymous variant (NM_007126.5, c.265C>T; p.Arg89Trp) in the valosin-containing protein gene, which was absent in the 1000 Genomes Project, the Exome Aggregation Consortium Database, and the Genome Aggregation Database, and was predicted to be "damaging" by PolyPhen-2 and "deleterious" using SIFT with a Combined Annotation Dependent Depletion score of 35. We also confirmed the absence of this variant in 505 Japanese control subjects. Therefore, we concluded that the variant in the valosin-containing protein gene was responsible for the symptoms of this patient.

A novel 1-bp deletion variant in DAG1 in Japanese familial asymptomatic hyper-CK-emia.

Asymptomatic hyper-CK-emia (ASCK) is characterized by persistent elevation of creatine kinase (CK) in serum without any neurological symptoms. We ascertained a two-generation family of ASCK patients without clear neurological abnormalities except for the high levels of serum CK (810.5 ± 522.4 U/L). We identified a novel 1-bp deletion variant in the DAG1 gene shared by the patients in the family (NM_001177639: exon 3: c.930delC:p.R311Gfs*70). The variant causes premature termination of translation at codon 477, resulting in a protein product completely devoid of the essential DAG1 domain. Since ASCK has been associated with DAG1 in only one case carrying compound heterozygous missense variants, our new finding of a novel 1-bp deletion revealed the previously unknown dominant effect of DAG1 on ASCK.

Dermal advanced glycation end-product accumulation is associated with sarcopenia-related measures in middle-aged and older men.

AIMS: Sarcopenia is the age-associated atrophy of muscles, and advanced glycation end-products (AGEs) accumulate in patients with age-associated diseases. We aimed to investigate the relationship between AGE accumulation in the skin and sarcopenia in middle-aged and older Japanese people. MATERIALS AND METHODS: We enrolled 240 participants in this cross-sectional study. The participants consisted of 120 men (mean age 68.8 ± 10.1 years) and 120 women (mean age 67.4 ± 9.0 years). The level of dermal AGE accumulation in the forearms was measured using skin autofluorescence (SAF) and many parameters associated with sarcopenia, including grip strength and thigh muscle cross-sectional area (CSA), were evaluated during medical check-ups at the Ehime University Hospital. RESULTS: Grip strength and thigh muscle CSA were significantly higher in men than women, but mean SAF did not significantly differ between them. There were significant correlations of age, height, C-reactive protein, glycated hemoglobin, grip strength, and thigh muscle CSA with SAF in men, but only age in women. Multivariate analysis showed that SAF was significantly independently associated with low grip strength in men (ß =-0.211, p =0.046). The men were then allocated to four groups according to their grip strength and thigh muscle CSA, and SAF was significantly higher in the lowgrip strength/low-thigh muscle CSA group than in the high-grip strength/high-thigh muscle CSA group (low/low group 2.25 ± 0.37 and high/high group 1.93 ± 0.36, p =0.001). CONCLUSIONS: SAF is associated with sarcopenia-related measures, especially grip strength, in middle-aged and older Japanese men, but not women.

A Japanese family with dystonia due to a pathogenic variant in SGCE.

Dystonia (DYT) is a heterogeneous neurological disorder, and there are many types of DYT depending on the responsible genes. DYT11 is an autosomal dominant DYT caused by functional variants in the SGCE gene. We examined a Japanese patient with myoclonic dystonia. By using exome analysis, we identified a rare variant in the SGCE gene, NM_003919.3: c.304C > T [Arg102*], in this patient. Therefore, this patient has been molecularly diagnosed with DYT11. By Sanger sequencing, we confirmed that this variant was paternally inherited in this patient. By allele-specific PCR, we confirmed that the maternally inherited normal allele of SGCE was silenced, and only the paternally inherited variant allele was expressed in this patient. Despite the pathogenicity, identical variants have been recurrently reported in eight independent families from different ethnicities, suggesting recurrent mutations at this mutational hotspot in SGCE.

Partial SPAST and DPY30 deletions in a Japanese spastic paraplegia type 4 family.

Spastic paraplegia type 4 (SPG4) is the most common autosomal dominant hereditary SPG caused by mutations in the SPAST gene. We studied the four-generation pedigree of a Japanese family with autosomal dominant hereditary SPG both clinically and genetically. Twelve available family members (ten affected; two unaffected) and two spouses were enrolled in the study. The clinical features were hyperreflexia in all four limbs, spasticity of the lower extremities, impaired vibration sense, mild cognitive impairment confirmed by the Wechsler Adult Intelligence Scale-Third Edition, and peripheral neuropathy confirmed by neurophysiological examinations. All four female patients experienced miscarriages. The cerebrospinal fluid tau levels were mildly increased in two of three patients examined. Linkage analyses revealed the highest logarithm of odds score of 2.64 at 2p23-p21 where the SPAST gene is located. Mutation scanning of the entire exonic regions of the SPAST gene by direct sequencing revealed no mutations. Exonic copy number analysis by real-time quantitative polymerase chain reaction revealed heterozygous deletion of exons 1 to 4 of the SPAST gene. Breakpoint analysis showed that the centromeric breakpoint was located within intron 4 of SPAST while the telomeric breakpoint was located within intron 3 of the neighboring DPY30 gene, causing a deletion of approximately 70 kb ranging from exons 1 to 3 of DPY30 to exons 1 to 4 of SPAST. To our knowledge, this is the first report of SPG4 associated with partial deletions of both the SPAST and DPY30 genes. The partial heterozygous deletion of DPY30 could modify the phenotypic expression of SPG4 patients with this pedigree.

Plasma amino acids in patients with essential tremor.

Essential tremor (ET) is one of the most common movement disorders. However, there are currently no accepted biomarkers for ET. This report suggested that concentration of plasma glutamic acid, aspartic acid, and taurine could be biomarkers for ET.

A Japanese hereditary spastic paraplegia family with a rare nonsynonymous variant in the SPAST gene.

Spastic paraplegia (SPG) type 4 is an autosomal dominant SPG caused by functional variants in the SPAST gene. We examined a Japanese family with three autosomal dominant SPG patients. These patients presented with typical symptoms of SPG, such as spasticity of the lower limbs. We identified a rare nonsynonymous variant, NM_014946.4:c.1252G>A [p.Glu418Lys], in all three family members. This variant has previously been reported in a Russian SPG family as a "likely pathogenic" variant.5 Ascertainment of additional patients carrying this variant in an unrelated Japanese SPG family further supports its pathogenicity. Molecular diagnosis of SPG4 in this family with hereditary spastic paraplegia is confirmed.

Unilateral lower limb atrophy associated with glomus tumors: a case report.

BACKGROUND: Glomus tumors are soft tissue neoplasms comprised of glomus cells, vasculature, and smooth muscle cells, which occur commonly in a single subungual area of the digits, and their main clinical features include severe paroxysmal pain, localized tenderness, and cold hypersensitivity. CASE PRESENTATION: A 47-year-old Japanese man had suffered from chronic progressive paroxysmal shooting pain in his right leg since childhood. He avoided putting weight on his right foot whenever he walked. The frequency of paroxysmal pain and the number of tender points both gradually increased with age, and his right leg gradually atrophied. Magnetic resonance imaging of the lower extremity demonstrated multiple gadolinium-enhanced nodules that corresponded with his tender points. Excisional biopsy relieved his pain and provided a histopathological diagnosis of glomus tumors. CONCLUSION: This case suggests that small glomus tumors located in deep tissue may cause disuse atrophy because of their long delay before diagnosis. Clinicians should consider the potential for glomus tumors when patients exhibit unilateral lower limb muscular atrophy with pain.

Vascular endothelial dysfunction associated with severity in multiple sclerosis.

BACKGROUND: Impairment of cerebrovascular reactivity (CVR) has been reported in patients with multiple sclerosis (MS). Chronic inflammation and endothelial dysfunction are possible mechanisms underlying this hemodynamic impairment. This study aimed to evaluate CVR and endothelial function in patients with MS and explore their relationships with disease progression using functional sonographic procedures. METHODS: Patients with MS and age-/sex-matched healthy controls were assessed for endothelial function, determined by flow-mediated dilation (FMD), and CVR, measured using the breath-holding index (BHI). RESULTS: Twenty-seven patients with MS and 24 healthy controls were enrolled. FMD was significantly lower in MS subjects than in control subjects (6.0 ± 0.6 vs. 8.6 ± 0.7, p = 0.006); furthermore, BHI was similarly lower in MS than in controls, but insignificant. Remarkably, FMD was significantly lower in secondary progressive MS subjects than in relapse-remitting MS subjects (3.7 ± 1.3 vs. 6.7 ± 0.7, p = 0.045). In addition, FMD was inversely correlated with the disability score as per the expanded disability status scale (R2 = 0.170, p = 0.033) and modified Rankin scale (R2 = 0.187, p = 0.027). CONCLUSION: In patients with MS, endothelial dysfunction was more noticeable than CVR impairment, correlating with the severity and progression of MS.

Ddhd1 knockout mouse as a model of locomotive and physiological abnormality in familial spastic paraplegia.

We have previously reported a novel homozygous 4-bp deletion in DDHD1 as the responsible variant for spastic paraplegia type 28 (SPG28; OMIM#609340). The variant causes a frameshift, resulting in a functionally null allele in the patient. DDHD1 encodes phospholipase A1 (PLA1) catalyzing phosphatidylinositol to lysophosphatidylinositol (LPI). To clarify the pathogenic mechanism of SPG28, we established Ddhd1 knockout mice (Ddhd1[-/-]) carrying a 5-bp deletion in Ddhd1, resulting in a premature termination of translation at a position similar to that of the patient. We observed a significant decrease in foot-base angle (FBA) in aged Ddhd1(-/-) (24 months of age) and a significant decrease in LPI 20:4 (sn-2) in Ddhd1(-/-) cerebra (26 months of age). These changes in FBA were not observed in 14 months of age. We also observed significant changes of expression levels of 22 genes in the Ddhd1(-/-) cerebra (26 months of age). Gene Ontology (GO) terms relating to the nervous system and cell-cell communications were significantly enriched. We conclude that the reduced signaling of LPI 20:4 (sn-2) by PLA1 dysfunction is responsible for the locomotive abnormality in SPG28, further suggesting that the reduction of downstream signaling such as GPR55 which is agonized by LPI is involved in the pathogenesis of SPG28.

Combined treatment with prednisolone and tacrolimus for myasthenia gravis with invasive thymoma.

We describe a case of recurrent invasive thymoma associated with myasthenia gravis that responded to combined treatment with prednisolone and tacrolimus. The patient suffered from a myasthenic crisis and received methylprednisolone pulse therapy and partial thymomectomy. Low maintenance doses of prednisolone and tacrolimus shrank the size of the invasive thymoma and maintained the patient without any myasthenic symptoms. We stress the usefulness of combined treatment with tacrolimus and prednisolone for invasive thymoma, especially for unresectable tumors.

Bilateral parkinsonism in a patient with infarcts involving the unilateral basal ganglia.

We describe a 61-year-old woman with bilateral parkinsonism caused by unilateral infarction limited to the territory of the lenticulostriate arteries. Although dopamine transporter imaging with single-photon emission computed tomography (DaTSPECT) demonstrated reduced putaminal tracer binding concordant with the size and location of the vascular lesion, the specific binding ratio was within the normal range. Five months after onset, the patient was free from parkinsonism without the use of any antiparkinsonian agents. When patients show bilateral parkinsonism, it is important to consider infarction of the lenticulostriate arteries. Additionally, DaTSPECT might be useful for predicting the prognosis of parkinsonism caused by infarction.