Natural history of transthyretin Val30Met familial amyloid polyneuropathy: analysis of late-onset cases from non-endemic areas.

OBJECTIVE: The objective of this study was to elucidate the natural history of late-onset transthyretin Val30Met-associated familial amyloid polyneuropathy (FAP ATTR Val30Met) in non-endemic areas. METHODS: The authors retrospectively assessed the development of major clinical landmarks and abnormalities of nerve conduction and cardiac examination indices in 50 patients with an age of onset older than 50 years and no relationship to endemic foci. RESULTS: Once the neuropathic process was initiated, sensory and motor symptoms of both the upper and lower extremities appeared within a period of one and a half years. Digestive and orthostatic symptoms also tended to occur in the early phase of the disease, whereas urinary symptoms appeared in the middle of the disease progress. Along with pain in the extremities, these symptoms progressed over time and significantly disturbed the quality of life during the late phase of the disease, resulting in the need for wheelchair use. Although cardiomyopathy became clinically apparent only in the late phase of the disease, it was found to be the major cause of death. The mean duration of the disease onset to death was 7.3 years. Although values at the time of diagnosis were extremely variable, serial measurements of electrophysiological indices, the cardiothoracic ratio and interventricular septum thickness indicated a steady exacerbation in these outcomes among patients within a span of a couple of years. CONCLUSIONS: The ages of onset of each clinical landmark were extremely variable between patients. However, once an initial symptom appeared, the chronological sequence of other clinical landmarks tended to be uniform, occurring within a relatively short time span.

Atypical Familial Amyotrophic Lateral Sclerosis with Slowly Progressing Lower Extremities-predominant Late-onset Muscular Weakness and Atrophy.

Objective Amyotrophic lateral sclerosis (ALS) is an adult-onset neurodegenerative disease characterized by the progressive loss of the upper and lower motor neurons that progresses to paralysis of almost all skeletal muscles of the extremities, bulbar, and respiratory system. Although most ALS cases are sporadic, about 10% are dominantly inherited. We herein report an atypical phenotype of familial ALS (fALS). To elucidate the phenotype-genotype correlation of this atypical phenotype of fALS, clinical and genetic investigations were performed. Methods and Patients Five sibling patients (three men, two women) from a Japanese family and one healthy sibling (a woman) were clinically interviewed and examined. Genetic analyses, including genome-wide linkage analyses and whole-exome sequencing, were performed using genomic DNA extracted from the peripheral blood samples of these siblings. Results The clinical features of fALS are characterized by slow progression (mean duration of the disease±standard deviation [SD]: 19.6±3.9 years) and lower extremities-predominant late-onset muscular weakness (mean onset of muscular weakness±SD: 52.8±2.6 years). Genetic analyses revealed novel heterozygous missense mutations of c.2668C>T, p.R890C in the PLEC gene and c.421G>C, p.V141L in the ST3GAL6 gene in all affected siblings. Conclusion A new atypical fALS family with a benign clinical course is herein reported. We identified two candidate gene mutations of PLEC and ST3GAL6 linked to this phenotype.

Identification of a new homozygous frameshift insertion mutation in the SIL1 gene in 3 Japanese patients with Marinesco-Sjögren syndrome.

Marinesco-Sjögren syndrome (MSS) is an autosomal recessive multisystem disorder characterized by cerebellar ataxia, cataracts, progressive muscular weakness, and developmental and mental retardation. Recently, mutations in the SIL1 gene on chromosome 5q31 have been shown to be a cause of MSS. We sequenced the entire SIL1-coding region in 3 unrelated Japanese patients with classical MSS and identified a novel homozygous frameshift insertion mutation, 936_937insG, in exon 9 in all 3 patients.

GCH1 mutations in dopa-responsive dystonia and Parkinson's disease.

Guanosine triphosphate cyclohydrolase I (GCH1) mutations are associated with increased risk for dopa-responsive dystonia (DRD) and Parkinson's disease (PD). Herein, we investigated the frequency of GCH1 mutations and clinical symptoms in patients with clinically diagnosed PD and DRD. We used the Sanger method to screen entire exons in 268 patients with PD and 26 patients with DRD, with the examinations of brain magnetic resonance imaging scans, striatal dopamine transporter scans, and [123I] metaiodobenzylguanidine (MIBG) myocardiac scintigraphy scans. We identified 15 patients with heterozygous GCH1 mutations from seven probands and five sporadic cases. The prevalence of GCH1 mutations in probands was different between PD [1.9% (5/268)] and DRD [26.9% (7/26)] (p value < 0.0001). The onset age tends to be different between PD and DRD patients: 35.4 ± 25.3 and 16.5 ± 13.6, respectively (average ± SD; p = 0.08). Most of the patients were women (14/15). Dystonia was common symptom, and dysautonomia and cognitive decline were uncommon in our PD and DRD. All patients presented mild parkinsonism or dystonia with excellent response to levodopa. Seven of seven DRD and three of five PD presented normal heart-to-mediastinum ratio on MIBG myocardial scintigraphy. Five of six DRD and three of four PD demonstrated normal densities of dopamine transporter. Our findings elucidated the clinical characteristics of PD and DRD patients due to GCH1 mutations. PD patients with GCH1 mutations also had different symptoms from those seen in typical PD. The patients with GCH1 mutations had heterogeneous clinical symptoms.

rt-PA with Antithrombotic Therapies in a Case with Capsular Warning Syndrome.

We herein report a case of capsular warning syndrome (CWS) that was successfully treated with recombinant tissue plasminogen activator (rt-PA). A 70-year-old woman had repeated stereotyped transient ischemic attacks (TIAs) of right hemiparesis and dysarthria. After hospitalization, argatroban, aspirin, and cilostazol were started but were ineffective. Thirteen hours after the first episode of TIAs, severe symptoms occurred. Magnetic resonance imaging showed acute infarctions in the internal capsule to corona radiata, so we used rt-PA. Since then, the TIAs have not occurred, and the symptoms have considerably improved. This case suggests that rt-PA might be effective and safe for use in treating CWS.

[A case of anti-MuSK antibody-positive myasthenia gravis with dropped head as the initial presenting symptom].

A 53-year-old woman was admitted to our hospital because of dropped head. Neurological examination showed no abnormality except for weakness of the neck extensor muscles. Her symptoms worsened in the evening, requiring her to support her head by placing her hand against her chin. Edrophonium and repetitive stimulation tests gave negative results, and anti-acetylcholine receptor antibodies were not detected. She had no thymoma. However, she was found to have a high serum titer of anti-MuSK antibody (37.3 nM). She was diagnosed as having myasthenia gravis (MG) and treatment with pyridostigmine was started. However, this had to be withdrawn because of fasciculation as an adverse effect. She was therefore treated with prednisolone, and this resulted in marked improvement. The initial presenting symptom in this case was dropped head, and there were none of the results of laboratory or electrophysiological examinations that are usually typical of MG. MG was eventually diagnosed by measurement of anti-MuSK antibody. The present case suggests that a patient presenting with dropped head without any obvious cause needs to be studied for the presence of anti-MuSK antibody.

Late-onset familial amyloid polyneuropathy: an autopsy study of two Japanese brothers.

We report an autopsy study of late-onset familial amyloid polyneuropathy with a variant transthyretin Val30Met in 2 brothers living in Kyoto, Japan. The disease onsets were at 64 and 59 years, and they died at 71 and 74 years old, respectively. They exhibited almost the same postmortem findings. Amyloid deposition was remarkable in the hearts, but was not seen in the renal glomeruli. In the peripheral nervous system, amyloid deposition was most prominent in the nerves immediately caudal to ganglia, moderate in the dorsal and sympathetic ganglia, and mild in the spinal roots, sciatic nerves, and distal nerves. The difference between the amyloid deposition in the proximal portion and distal portion of the extremity nerves appeared to be greater in the late-onset type than in the ordinary type, and this proximal deposition of amyloid may have induced severe distal nerve fiber degeneration.

Leber's hereditary optic neuropathy with intracranial arteriovenous malformation: a case report.

We reported a patient with Leber's hereditary optic neuropathy (LHON) with an intracranial arteriovenous malformation (AVM). Genetic analysis of this patient revealed a point mutation in mitochondrial DNA (mtDNA) at nucleotide position 11,778 in the ND4 subunit of complex I. Although the relationship between intracranial AVM and mtDNA mutations remains uncertain, some patients with intracranial AVM may be associated with mitochondrial abnormality. Further study is necessary to confirm whether the above conditions are coincidental or closely interrelated.

A case of Marinesco-Sjögren syndrome: MRI observations of skeletal muscles, bone metabolism, and treatment with testosterone and risedronate.

Marinesco-Sjögren syndrome (MSS) is a rare autosomal recessive disorder characterized by cerebellar ataxia, congenital cataracts, mental retardation, primary hypogonadism, skeletal abnormalities and myopathy, and patients with MSS are considered to be at risk of falls and bone fractures. We report a patient with MSS who received testosterone replacement therapy and risedronate administration. Muscle strength and the MRI features of the skeletal muscles were not changed, but low bone mass was improved by these treatments, and improvement has continued after risedronate treatment alone. This case suggests that treatment of MSS-related low bone mass using bisphosphonates is likely beneficial.

Distinct characteristics of amyloid deposits in early- and late-onset transthyretin Val30Met familial amyloid polyneuropathy.

Late-onset transthyretin Val30Met-associated familial amyloid polyneuropathy (FAP ATTR Val30Met) cases unrelated to endemic foci in Japan show different clinicopathological features from the conventional early-onset cases in endemic foci. We compared the characteristics of amyloid deposits in early-onset FAP ATTR Val30Met cases in endemic foci and late-onset cases in non-endemic areas. Amyloid deposits in three early-onset cases from endemic foci and five late-onset cases from non-endemic areas were systematically examined post-mortem. Amyloid deposits in early-onset cases were highly congophilic and showed strong apple-green birefringence with Congo red staining and had long, parallel fibrils in most organs. On the other hand, those in late-onset cases were generally weakly congophilic and showed faint apple-green birefringence with Congo red staining and had short, haphazard fibrils. In the renal glomus and adrenal gland of early-onset cases, the characteristics of amyloid deposits were similar to those observed in late-onset cases. Analysis of cardiac amyloid using surface enhanced desorption/ionization time-of-flight mass spectrometry indicated that most transthyretin (TTR) was variant in early-onset cases, while more than half was composed of wild-type TTR in late-onset cases. Although characteristics of amyloid deposits may differ among individual organs of respective cases, especially in early-onset cases, the pattern was distinct between early- and late-onset cases. Amyloid deposition in late-onset cases may be similar to that observed in senile systemic amyloidosis with wild-type TTR deposition, suggesting that aging may play an important role in these cases.