Expansions of intronic TTTCA and TTTTA repeats in benign adult familial myoclonic epilepsy.

Epilepsy is a common neurological disorder, and mutations in genes encoding ion channels or neurotransmitter receptors are frequent causes of monogenic forms of epilepsy. Here we show that abnormal expansions of TTTCA and TTTTA repeats in intron 4 of SAMD12 cause benign adult familial myoclonic epilepsy (BAFME). Single-molecule, real-time sequencing of BAC clones and nanopore sequencing of genomic DNA identified two repeat configurations in SAMD12. Intriguingly, in two families with a clinical diagnosis of BAFME in which no repeat expansions in SAMD12 were observed, we identified similar expansions of TTTCA and TTTTA repeats in introns of TNRC6A and RAPGEF2, indicating that expansions of the same repeat motifs are involved in the pathogenesis of BAFME regardless of the genes in which the expanded repeats are located. This discovery that expansions of noncoding repeats lead to neuronal dysfunction responsible for myoclonic tremor and epilepsy extends the understanding of diseases with such repeat expansion.

Genetic association between Notch4 polymorphisms and Alzheimer's disease in the Japanese population.

It is shown that Notch 4 plays important roles in the pathogenesis of Alzheimer's disease (AD). To investigate whether three single nucleotide polymorphisms (SNPs) of the Notch4 gene are associated with AD, the three SNPs were genotyped by a polymerase chain reaction-restriction fragment length polymorphism method for 243 AD patients and 130 age-matched controls. We also confirmed the linkage disequilibrium among these three SNPs of the gene using the EH program. The three SNPs did not seem to alter risk for AD. Our study suggests that SNPs studied are not associated with AD. The linkage disequilibrium of this locus indicates that there is genetic heterogeneity in the Notch4 gene. We could not confirm the previous synergetic associations of the 5' untranslated region (rs367398) C/C genotype in apolipoprotein E epsilon4 bearers in AD patients. Potential markers nearby the 5' untranslated region polymorphism might affect risk for AD.

Genetic association between USF 1 and USF 2 gene polymorphisms and Japanese Alzheimer's disease.

To investigate the effect of single nucleotide polymorphisms (SNPs) of the upstream stimulatory factor (USF) 1 and 2 genes on the onset of Alzheimer's disease (AD), a case-control study was performed. The SNPs were genotyped by a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method in 236 AD patients and 120 age-matched controls of Japanese descent. We observed no significant association between the three SNPs of the USF 1 gene and AD in our Japanese participants. In addition, the SNPs studied did not affect plasma cholesterol levels in our AD cases. For the USF 2 gene, the two SNPs did not show significant association with onset of AD. Our study suggests that the three SNPs of the USF 1 gene and two SNPs of the USF 2 gene presented here are not associated with onset of AD.

Genetic association between Notch4 polymorphisms and Japanese schizophrenics.

The objective of this study was to investigate whether three single nucleotide polymorphisms of the Notch4 gene are associated with the onset of schizophrenia. To confirm the linkage disequilibrium among these three single nucleotide polymorphisms of the gene, the three single nucleotide polymorphisms were genotyped by a polymerase chain reaction-restriction-fragment length polymorphism method for all samples. The genotypic frequencies of each single nucleotide polymorphism in the schizophrenic were compared with respective controls using a chi method. To check linkage disequilibrium, the haplotype frequency program was utilized. No statistical association between the two single nucleotide polymorphisms of the Notch4 gene and schizophrenia was observed in our Japanese samples. Although one nonsynonymous single nucleotide polymorphism did show a weakly significant P-value, its allelic frequencies are not positive. Two of the single nucleotide polymorphisms showed strong linkage disequilibrium in our Japanese samples. The single nucleotide polymorphism between the other two single nucleotide polymorphisms showed a weaker linkage disequilibrium with the others. Our study suggests that the three single nucleotide polymorphisms are not associated with the onset of schizophrenia. The linkage disequilibrium of this locus indicates that there is genetic heterogeneity in the Notch4 gene. Linkage disequilibrium may differ among ethnic groups, and so a larger study should be performed in this region.

No genetic association between the myeloperoxidase gene -463 polymorphism and estrogen receptor-alpha gene polymorphisms and Japanese sporadic Alzheimer's disease.

Myeloperoxidase (MPO) presence has been demonstrated in microglia associated with senile plaques and contributes to Alzheimer's disease (AD) pathology through oxidation-induced damage. MPO activity is normally higher in women than in men. Additionally, a functional biallelic (G/A) polymorphism in the promoter region (-463) of the MPO gene has been associated with a gender-specific risk factor for AD, but reports of this association have been inconsistent. Furthermore, estrogen is known to enhance MPO activity in myeloid cells and increases the amount of MPO in plasma. Recently, estrogen replacement therapy has been reported to reduce the risk of developing AD and to help maintain cognitive function in patients with AD. In the current study, we analyzed the MPO -463 polymorphism and two estrogen receptor-alpha polymorphisms in 205 Japanese sporadic AD patients and 92 controls. The results suggest that there is no significant difference in the genotypic frequencies and allelic frequencies of the MPO -463 polymorphism and the estrogen receptor-alpha polymorphisms between the Japanese sporadic AD group and the control group.

No genetic association between ATP binding cassette proteins and Japanese sporadic Alzheimer's disease.

The identification of the epsilon4 variant of apolipoprotein E as a genetic risk factor for late-onset Alzheimer's disease (AD) suggests that cholesterol may play a direct role in the pathogenesis of the disease. Recent studies have suggested that the ATP-binding cassette (ABC) protein G5 (ABCG5) may be involved in the regulation of intestinal cholesterol absorption. Furthermore, genetic variation of this locus may affect blood cholesterol concentrations. We therefore studied whether the ABCG5 C1950G (Gln640Glu) polymorphism affects the risk of AD. In addition, there was no difference in mean baseline cholesterol concentrations between individuals with the C/C genotype and carriers of the G allele. Recent studies have shown that genetic regions including the ABCA12 gene might also be associated with the risk of AD. The ABCA12 gene, located <1 Mb from the peak marker on chromosome 2q34, is also a member of the ABC transporter superfamily. In the current study, two common polymorphisms of the ABCA12 gene, rs952718 (T/G) and rs956133 (A/G), were analyzed in our subjects. These polymorphisms showed no association with the risk of AD. Furthermore, we observed weak linkage disequilibrium between these two single nucleotide polymorphisms. These results indicate that the common polymorphisms of the ABCG5 and ABCA12 genes investigated here are not associated with AD.

Genetic association between matrix metalloproteinase MMP-9 and MMP-3 polymorphisms and Japanese sporadic Alzheimer's disease.

Recent studies suggested that matrix metalloproteinases (MMPs) might play an important role in the pathophysiology of Alzheimer's disease (AD). MMP-9 and MMP-3 are reported to degrade amyloid beta and have several functional polymorphisms associated with other common diseases. Four common polymorphisms in each of MMP-9 and MMP-3 were examined in AD cases and normal control individuals. Common polymorphisms of MMP-9, rs3918248, rs2664538, rs2250889 and rs2274756 showed no association with risk for AD. We observed strong linkage disequilibrium (LD) between rs2664538 and rs2250889 in our Japanese samples. The polymorphisms of MMP-3; 5A/6A insertion polymorphism in the promoter, rs3025079, rs520540 and rs679620 also did not influence risk for AD. LD of the 5A/6A polymorphism with rs679620 was relatively strong. These results suggest that the common polymorphisms of MMP-9 and MMP-3 investigated here are not associated with AD.

Life style risks of Parkinson's disease: association between decreased water intake and constipation.

Gastrointestinal dysfunction, especially constipation, is one of the major problems in the daily life of patients with Parkinson's disease (PD). About 60 to 80% of PD patients suffer from constipation. Several studies have proven that constipation appears about 10 to 20 years prior to motor symptoms. More recently, Abbott et al. have found from a large scale prospective study that lower frequency bowel movements predict the future risk of PD. Furthermore, Braak et al. have found that Lewy neuritis and Lewy bodies, the hallmarks of PD pathology, appear in the dorsal nucleus of vagus in the earliest stage of the disease and then extend upward through the brain stem to reach the substantia nigra in the third stage. They also hypothesize that some yet undefined toxins break through the mucosal barrier of the intestine and are incorporated into the axon terminal of the vagus nerve and transported in a retrograde manner to the vagus nucleus. In this study, we assessed bowel movements and nutritional status in Japanese patients with PD. We found that intake of water was significantly decreased in PD patients from early life and associated with their constipation. Ninety four patients with PD (M 50, F 44) were enrolled. Nutritional status was assessed using the Self-administered Diet History Questionnaire (DHQ). Total water intake was calculated from the consumption of coffee, green tea, and tea. We also questioned the behavior of water drinking from the early stage of life. The questionnaire for bowel movements concerned the frequency of defecation, age of onset of constipation, and age of onset of motor dysfunction. Less than one bowel movement in 3 days was defined as constipation. The nutritional status of PD patients did not differ significantly from those of controls though several studies have shown excess intake of animal fats or reduced consumption of coffee are risks in PD. In contrast, water intake was significantly lower in PD patients than controls (604.0+/-377.2 ml/d vs 909.5+/-531.6 ml/d; P<0.0001). Interestingly, PD patients tended not to feel thirsty and thus they had no desire to drink water throughout their life. Seventy four patients out of 94 (78.7 %) complained of constipation. Mean bowel frequency was once per 3.3+/-1.1 days and 71.1% of patients were defined as having constipation. Women suffered from constipation more frequently than men (82.4% vs 61.9 %). In 33 patients out of 74 (44.6 %), onset of constipation preceded motor disturbance by an average time of 18.1+/-18.8 years. Furthermore, the amount of water intake correlated inversely with the severity of constipation and the depletion of water intake preceded constipation in most cases. The present results support previous findings that constipation precedes the onset of motor dysfunction in PD. To our knowledge, this is the first report to point out latent water depletion in PD patients. It is not certain at present whether coffee or caffeine themselves are the protective factor for PD or alternatively the amount of water in coffee drinking is more essential. Prospective studies on a large scale are necessary to elucidate the real meaning of water depletion in PD.

No genetic association between Fyn kinase gene polymorphisms (-93A/G, IVS10+37T/C and Ex12+894T/G) and Japanese sporadic Alzheimer's disease.

Several groups have reported that abnormal phosphorylation of tau by Fyn, a protein-tyrosine kinase, may play a role in the neuropathogenesis of Alzheimer's disease (AD). In the present study, three common Japanese polymorphisms of the Fyn gene (-93A/G in the 5'-flanking region, IVS10+37T/C in intron 10 and Ex12+894T/G in the 3'-untranslated region) were studied in 127 healthy controls and 182 sporadic AD cases using a polymerase chain reaction restriction fragment length polymorphism method. A comparison of the allelic and genotypic frequencies of these polymorphisms between controls and sporadic AD cases failed to show any significant difference. These results suggest that the Fyn polymorphisms (-93A/G, IVS10+37T/C and Ex12+894T/G) investigated here have no genetic association with sporadic AD.

No genetic association between tumour necrosis factor receptor II 196R polymorphism and Japanese sporadic Alzheimer's disease.

Recent studies have reported that acute effects of tumour necrosis factor (TNF), a pro-inflammatory cytokine, are limited by binding to a soluble receptor, TNF receptor II, and the G allele at position 196 in exon 6 of the TNF receptor II gene (TNFRII 196R) has been associated with auto-immune diseases. Since complex interactions among cytokines have been suggested around senile plaques in Alzheimer's disease, TNF might be associated with ageing and the pathophysiology of Alzheimer's disease. We examined the TNFRII 196R polymorphism in 243 Japanese sporadic Alzheimer's disease cases and 106 control cases using a polymerase chain reaction-restriction fragment length polymorphism method. Allelic frequencies with TNFRII 196R T/G polymorphism were 28.3% and 27.4% in the control and Alzheimer's disease groups, respectively. The results showed no genetic association between TNFRII 196R polymorphism and Alzheimer's disease. The TNFRII 196R G allele does not appear to be associated with Alzheimer's disease susceptibility in a Japanese population.

Involuntary expiratory phonation as a dose-related consequence of L-dopa therapy in a patient with Parkinson's disease.

We report a case of involuntary phonation caused by abnormal vocal cord movements during expiration in a patient with Parkinson's disease. A 60-year-old woman had been treated for parkinsonism at the outpatient clinic of the Department of Neurology since August 1999. She began to groan involuntarily in the daytime in September 2001. She could not eat well while groaning. Stridor was not noted during sleep at night. Endoscopic examination of the larynx revealed insufficient abduction of the bilateral vocal cords, although the glottis was not so small as to cause stridor during inspiration. During expiration, however, the vocal cords adducted, resulting in the involuntary production of voice. Electromyography showed an increase in the activity of the thyroarytenoid and lateral cricoarytenoid muscles. This muscle activity was further enhanced during inspiration. The involuntary phonation disappeared when the patient's dose of L-dopa was decreased, although she had a decrease in her systemic mobility as well. When the dose of L-dopa was increased to the therapeutic level, involuntary phonation recurred, and her voluntary systemic activity improved. In the present case, it was considered that excessive dopaminergic denervation occurred in the nerve innervating the laryngeal adductors. Involuntary voice appeared to be produced by hypertonus of the laryngeal adductors because of a lowering in the threshold level for L-dopa, even though the drug was administered at the usual dose.

[The Japanese version of RBANS (Repeatable Battery for the Assessment of Neuropsychological Status)].

In Japan, neuropsychological assessment of dementing illnesses has been done mainly using Mini-Mental State Examination (MMSE) and a revised version of Hasegawa Dementia Scale (HDS-R). However, because of a lack of appropriately designed test domains, early detection of senile dementia and/or cognitive impairment is hardly possible, even if using these batteries. This paper is to introduce a Japanese Version of RBANS (Repeatable Battery for the Assessment of Neuropsychological Status) which was originally developed by Randolph and revised by us. The entire battery of Japanese Version RBANS took less than 30 minutes to administer, and yielded scaled scores for five cognitive domains such as immediate memory, visuospatial/constructional ability, language, attention, and delayed memory. On RBANS, abnormal cognitive decline in the older adult was much easily detected, being compared to MMSE and HDS-R: 52 normal volunteer subjects ranging from 24 to 80 years old showed a significant (p < 0.05 on t test) impairment of delayed and immediate memories due to ageing. The aged (60-79) subjects with average scores of MMSE and HDS-R being over 25, significantly showed impairment of both immediate memory (list and story learnings) and delayed memory (list, story and figure recalls). The present data suggest that the Japanese Version RBANS is useful for both detecting and characterizing early dementia, and should be widely utilized for a neuropsychological screening battery in the clinical practice throughout Japan.

Effect of IL-6 polymorphism on risk of Alzheimer disease: genotype-phenotype association study in Japanese cases.

Interleukin-6 (IL-6), an inflammatory cytokine might be involved in the pathophysiology of Alzheimer disease (AD); several studies have reported that the "C allele of IL-6 variable number of tandem repeat polymorphism" (IL-6vntr) delayed initial onset of AD and also decreased its risk per se. Another polymorphism, G/C allele of IL-6 gene promoter region (IL-6prom), is also a candidate because it has an influence on the regulation of plasma IL-6 concentration. We examined these IL-6 polymorphisms in 128 Japanese AD cases and 83 control cases using a PCR-RFLP method. The results showed the frequency of the IL-6prom G allele was significantly increased in AD, although IL-6vntr polymorphism was not. Plasma IL-6 concentration of the AD cases was also significantly higher than that of the control cases. Moreover, the IL-6prom G allele-positive AD patients showed a tendency to have higher IL-6 concentration in the AD group. These findings suggest that the IL-6prom G allele which may affect plasma IL-6 concentration might be a risk factor for sporadic AD in Japanese.