Michiaki Miwa

Clinical and histopathological features of progressive-type familial amyloidotic polyneuropathy with TTR Lys54

The purpose of this study was to evaluate the clinical and pathological features in patients with progressive-type familial amyloidotic polyneuropathy (FAP) using autopsy and biopsy specimens. A proband is a 33-year-old man with FAP type I who developed motor, sensory and autonomic impairments with neuropathy, heart failure, and anorexia. Genetic findings of transthyretin (TTR) revealed G to A transition in codon 54 causing a rare mutation of TTR Lys54. He died of pneumonia and severe cardiac failure 4 years after onset. Autopsy showed heavy amyloid deposition in the heart, peripheral nerves, thyroid, skin, fat tissue, prostate and testis, moderate in the sympathetic nerve trunk, vagal nerve, celiac plexus, pelvic plexus, bladder, gastrointestinal tract, tongue, pancreas, lung, pituitary, blood vessel, gall bladder, adrenals and muscles, and free in the central nervous system, liver, kidney and spleen. Sural nerve biopsy in a sibling confirmed TTR amyloidosis immunohistochemically. Electronmicroscopic findings of amyloid fibrils were similar to that of FAP Met30. Immunoelectronmicroscopic findings indicated the relationship between amyloid fibrils or non-fibrillar structure and collagen fibers. The distribution of amyloid deposition, heavy in the heart and lacking in the kidney, is a characteristic feature and reflected severity of FAP with TTR Lys54.

A Japanese SCA5 family with a novel three-nucleotide in-frame deletion mutation in the SPTBN2 gene: a clinical and genetic study

To date, four families with spinocerebellar ataxia type 5 (SCA5) with four distinct mutations in the spectrin, beta, nonerythrocytic 2 gene (SPTBN2) have been reported worldwide. In the present study, we identified the first Japanese family with SCA5, and analyzed this family clinically and genetically. The clinical features of the five patients in this family revealed late-onset autosomal-dominant pure cerebellar ataxia. We collected DNA samples from the majority of the family members across two generations, and exome sequencing combined with Sanger sequencing revealed a novel heterozygous three-nucleotide in-frame deletion mutation (c.2608_2610delGAG) in exon 14 of the SPTBN2 gene. This mutation cosegregated with the disease in the family and resulted in a glutamic acid deletion (p.E870del) in the sixth spectrin repeat, which is highly conserved in the SPTBN2 gene. This is the first three-nucleotide in-frame deletion mutation in this region of the beta-3 spectrin protein highly likely to be pathogenic based on exome and bioinformatic data.

Novel mutations in the PNPLA6 gene in Boucher-Neuhäuser syndrome.

On whole-exome sequencing, a novel compound heterozygous mutation (c.2923A>G/c.3523_3524insTGTCCG, p.T975A/p.1175_1176insVS) and a novel homozygous one (c.3534G>C, p.W1178C) in the PNPLA6 gene were identified in sporadic and familial Japanese patients with Boucher-Neuhäuser syndrome (BNS), respectively. However, we did not find any mutations in the PNPLA6 gene in 88 patients with autosomal recessive hereditary spastic paraplegia (ARHSP). Our study confirmed the earlier report that a PNPLA6 mutation causes BNS. This is the first report on PNPLA6 mutations in non-Caucasian patients. Meanwhile, PNPLA6 mutations might be extremely rare in Japanese ARHSP patients. Moreover, we first found hypersegmented neutrophils in two BNS patients with PNPLA6 mutations.

Exome sequencing reveals a novel missense mutation in the KIAA0196 gene in a Japanese patient with SPG8.

Exome sequencing revealed a novel missense mutation (c.2152G>A, p.E713K) in the KIAA0196 gene in a Japanese patient with SPG8. To date, only 10 mutations in the KIAA0196 gene have been reported in the world. We describe the clinical and genetic findings in our patient with SPG8, which is a rare dominant hereditary spastic paraplegia. Notably, our patient showed mild upper limb ataxia, which is a relatively atypical symptom of SPG8. Thus, our patient showed a wide clinical spectrum of SPG8.

Rhythmic pupillary oscillation in Creutzfeldt‐Jakob disease associated with the Glu/Lys mutation of prion protein codon 200

We report two Creutzfeldt‐Jakob disease (CJD) patients with rhythmic pupillary and palpebral oscillation who had a mutation of prion protein codon 200 that resulted in the substitution of lysine for glutamate (Glu/Lys). Alternating dilation and constriction of the pupils combined with elevation and descent of the eyelids occurred in correspondence with periodic sharp wave complexes (PSWCs) on the electroencephalogram and with myoclonus of the head, face, and extremities. The onset of pupillary dilation and palpebral elevation coincided with the PSWCs. Initiation of these rhythmic pupillary and palpebral movements may depend on sympathetic activity, but the site of the generator is unclear. Such rhythmic pupillary and palpebral oscillation may be a feature of rapidly progressive CJD with predominant right hemispheric involvement.

プリオン蛋白遺伝子のコドン180と232にdouble mutationをみとめたCreutzfeldt-Jakob病の1例

Creutzfeldt-Jakob disease (CJD) presents with rapidly progressive dementia associated with several symptoms including pyramidal, extrapyramidal, and cerebellar signs. In Japan, patients with PRNP gene mutations comprise 18.3% of CJD cases. In the present study, we report a 74-year-old man with a double mutation in the PRNP gene. He showed dysarthria, gait disturbance, and cognitive impairment. High signal intensity was observed in the bilateral cortex on brain MRI in diffusion-weighted images. There were high total Tau protein and 14-3-3 protein levels in the cerebrospinal fluid. We diagnosed him as having CJD clinically, and analyzed the PRNP gene, which revealed a V180I mutation and a M232R one, i.e., a compound heterozygous status. In our patient, the disease has very slowly progressive (total disease course, 37 months). The V180I and M232R mutations are specific mutations to Japanese CJD patients. For patients with a double PRNP gene mutation, only V180I and M232R have been known. Patients with a double mutation (V180I /M232R) in the PRNP gene might show an atypical disease course with a slow progression.

Exome sequencing shows a novel de novo mutation in ATL1

We experienced treating a male patient born to healthy parents, who presented with spastic gait from childhood, and his son and daughter similarly presented with spastic gait, raising the possibility of a de novo mutation in the patient. With the hypothesis of a de novo mutation in the patient, we carried out exome sequencing of the patient and his parents to identify the gene with a disease‐causative mutation in the patient.

A case of cryptococcal ventriculitis with slowly progressive gait disturbance and memory impairment as initial symptoms

A 54-year-old man was admitted due to progressive gait disturbance and cognitive impairment. On MRI, a hyperintense region was observed in the periventricular white matter on FLAIR imaging, with Gd-enhancement in the choroid plexus and periventricular wall. Cerebrospinal fluid (CSF) examination showed marked abnormalities including a high white blood cell count (WBC, 360 cells/mm(3). 83% lymphocytes), an elevated protein level (1,416 mg/dl), a low glucose level (12 mg/dl), and elevated cryptococcal antigen with positive Indian ink staining. Cryptococcal ventriculitis was diagnosed. The patient was initially treated with liposomal amphotericin B, fluconazole, voriconazole, and flucytosine for 38 weeks, followed by administration of itraconazole and fluconazole with some improvement. The brain MRI after one month showed septum formation in the posterior horn, which was suggestive of ventriculitis. Although ventriculitis is rare, we should pay attention to the presence of ventriculitis due to cryptococcal infection in the central nervous system.

Active vasodilation by sympathetic outflow to limb skin in a patient with progressive aphasia.

Despite considerable interest, a pure vasodilator response by skin sympathetic nerve activity (SSNA) bursts in human limbs has not been observed in previous studies. In a patient with progressive nonfluent aphasia, SSNA, sympathetic skin response, and skin blood flow were simultaneously recorded at rest and during electrical stimulation. There was a very low frequency of SSNA bursts at rest, and when electrical stimulation was delivered, reflex bursts of SSNA were always observed followed by a sympathetic skin response and an increase in skin blood flow. The reflex latency of SSNA was slightly prolonged and the mean amplitude of reflex SSNA bursts was lower after electrical stimulation, compared with the responses in healthy controls. We report for the first time that the active vasodilator component of cutaneous sympathetic activity in limbs was recorded without any vasoconstrictor component in a patient with progressive aphasia.