Abnormalities in the axonal cytoskeleton induced by a connexin32 mutation in nerve xenografts

The X-linked form of Charcot-Marie-Tooth neuropathy is associated with mutations in the connexin32 (Cx32) gene. The functional role of Cx32 in Schwann cells and the relationship of these mutations to the progressive axonal loss and distal limb weakness seen in this disease have not been elucidated. To investigate the local influence of Schwann cells bearing the Cx32 gene defect on axonal cytoskeleton and the myelination process, the nerve xenograft model was used to transfer a Cx32 missense mutation (Glu102Gly) from human to an in vivo myelination system in nude mice. Twelve nerve grafts from two family members with Cx32 mutations and 17 grafts from three healthy individuals were generated by end-to-end anastomosis of approximately 6-mm sural nerve fascicles into the cut ends of the sciatic nerve in nude mice. Specimens were examined at 2, 4, 8, 12, and 16 weeks. Ultrastructural morphometric analysis showed Schwann cells with Cx32 mutation have a profound effect on the nude mice axons, resulting in an increase in neurofilament density, a depletion of microtubules associated with fragmentation of smooth axonal reticulum, and increased vesicles and mitochondria. At 16 weeks, axonal enlargement was evident within the proximal part of the graft; axonal atrophy, degeneration, and fiber loss were seen in distal-graft and host segments. The myelination process was not affected. We conclude that Cx32 mutation impairs a modulatory function of Schwann cells on axons, resulting in profound cytoskeletal alterations leading to distal axonal degeneration. These observations emphasize the role of impaired Schwann cell-axon interactions in the pathogenesis of hereditary neuropathies. J. Neurosci. Res. 51:174–184, 1998. © 1998 Wiley-Liss, Inc.     

Abnormalities in the axonal cytoskeleton induced by a connexin32 mutation in nerve xenographs

Sahenk Z, Chen L. 1998. Abnormalities in the axonal cytoskeleton induced by a connexin32 mutation in nerve xenographs. J Neurosci Res 51:174–184. On page 177, in Figure 2 of the article referenced above, the loading order of the lanes was incorrect and should be A C G T (not A T G C); the first five bases of the nucleotide sequences in both normal and mutant, reading up from the bottom should be CACAT; the amino acids are correctly identified. The author regrets this error.     

Unusual features of central nervous system involvement in CMTX associated with a novel mutation of GJB1 gene

In this study, we report a novel connexin 32 (CX32) mutation associated with cognitive impairment and a differential degree of peripheral nerve involvement. We present clinical, electrophysiological, and neuroimaging data on a family with X‐linked Charcot‐Marie‐Tooth disease caused by a 41A>G mutation of the gap junction protein beta 1 (GJB1) gene. The proband and her sister presented with a severe neuropathy with subclinical cognitive impairment; the proband's brother showed severe cognitive impairment and a mild neuropathy. This family report confirms that Charcot‐Marie‐Tooth type X is a clinically heterogeneous group, with great variability of phenotypes, possible severe involvement in females and clinical signs of cognitive impairment. Thus, this novel mutation should be added to the group of CX32 mutations with a central nervous system phenotype.     

X-Linked Charcot-Marie-Tooth disease caused by a novel point mutation in the connexin-32 gene

We report the clinical and electrophysiological findings of a patient with X-linked Charcot-Marie-Tooth disease and a novel point mutation in the connexin-32 gene. A 31-year-old man presented with a 5 year history of progressive imbalance and distal weakness in his legs. Electrophysiological studies confirmed an asymmetric, predominantly axonal sensorimotor neuropathy with some demyelinating features. Genetic testing revealed a G/A transition (Ala40Thr) in a conserved transmembrane region of the connexin-32 gene. Received: 13 April 2002 / Accepted in revised form: 18 June 2002 Correspondence to R.P. Grewal     

X-linked Charcot-Marie-Tooth disease: phenotypic expression of a novel mutation Ile127Ser in the GJB1 (connexin 32) gene

We report a family with X-linked dominant Charcot-Marie-Tooth disease (CMTX1). Three affected family members are described, who underwent detailed clinical, electrophysiological, molecular genetic, and histopathological studies. A novel isoleucine at position 127 with serine (Ile127Ser) mutation in the gap junction protein beta 1 (GJB1) gene was detected. The electrophysiological findings were consistent with a primary demyelinating neuropathy with secondary axonal loss and support this model of disease progression. All patients having the CMT phenotype and intermediate conduction velocities who are negative for CMT1A duplication/hereditary neuropathy with liability to pressure palsies (HNPP) deletion, and whose family shows a dominant trait without male-to-male transmission, should be screened for CMTX1.     

Neuropsychological and neuroimaging phenotype induced by a CAMTA1 mutation

Background/Aims: CAMTA1 mutations have recently been reported in families with intellectual disability and/or non-progressive congenital ataxias. The objective of this study was to describe the neuropsychological and neuroimaging phenotype of CAMTA1 mutation. Methods: We performed neuropsychological examinations, MRI and FDG-PET imaging in three patients with autosomal dominant mild intellectual disabilities and ataxia induced by a CAMTA1 intragenic deletion at 1p36.31p36.23. Results: Neuropsychological tests showed similar findings in two patients, with low information processing speed, slow memory consolidation, phonological disorders, working memory deficits, but mainly preserved executive function. Bilateral parietal and medial temporal abnormalities were found on brain MRI. Diffuse parieto-occipital and local left temporo-parietal decrease of FDG uptake was observed on PET images. Conclusion: These results suggest that CAMTA1 mutation may induce an unusual neuropsychological profile and parieto-temporal developmental abnormalities. We recommend screening for CAMTA1 mutations in patients with autosomal dominant mild intellectual disability presenting with similar a phenotype.     

Intermittent vagal nerve stimulation in paediatric patients: 1-year follow-up

OBJECT: Vagal nerve stimulation (VNS) has recently been proposed as a valid treatment for adult patients with drug-resistant partial epilepsy. Little experience in children has been reported. In order to evaluate the clinical efficacy and tolerance of VNS, we studied 13 paediatric patients with drug-resistant partial epilepsy. METHODS: Improvement in seizure frequency was estimated by calculating the percentage of change in seizure frequency during each 3-month period following initiation of VNS, compared with the 3-month period prior to the implantation of the VNS device. The improvement in quality of life (QOL) was evaluated with the Vineland Behavior Adaptive Scale (VBAS). RESULTS: In all patients, the surgical procedure was well tolerated. A recent modification of the implantation technique needing only a single cervical incision, has further reduced the aesthetic damage, particularly in small children who have a reduced muscular mass. Three months after the surgical procedure, 10 of the 13 patients demonstrated a seizure reduction rate greater than 50%. At the 1-year follow-up these positive results were maintained: 6 out of 8 patients continued to demonstrate a seizure reduction rate greater than 50%. Comparison with the pre-implantation period also showed a significant improvement in QOL in 4 out of 8 patients. We conclude that VNS is a valid treatment modality in children with drug-resistant partial epilepsy.     

Nemaline body myopathy caused by a novel mutation in troponin T1 (TNNT1)

Introduction: Nemaline myopathy is a rare disorder characterized by skeletal muscle weakness of varying severity and onset, with the presence of nemaline rods on muscle biopsy. Congenital nemaline body myopathy due to mutations in TNNT1 has hitherto only been described as a result of a single founder mutation in patients of Amish origin and in 2 other individuals with different recessive mutations. Methods: Autozygosity mapping and whole exome sequencing were applied after we identified 9 Palestinian patients from 7 unrelated families who have nemaline myopathy. Results: All patients were homozygous for a novel complex rearrangement of the TNNT1 gene (c.574_577delinsTAGTGCTGT | NM_003283) leading to C‐terminal truncation of the protein (p.L203* | NP_003274.3). Their clinical course was remarkable for early respiratory failure and striking stiffness of the cervical spine. Conclusions: This report exemplifies the utility of combining autozygosity mapping and whole exome sequencing and expands the phenotype associated with TNNT1 mutations. Muscle Nerve 53 : 564–569, 2016     

Insight in early psychosis: a 1-year follow-up

Insight was investigated in 180 individuals consecutively admitted to a comprehensive early psychosis treatment program. Insight was assessed on admission and after 3, 6 and 12 months. Insight improved significantly over 12 months, and was negatively correlated with both positive and negative symptoms, and positively correlated with depressive symptoms at admission. There were no associations with cognition.     

Magnetoencephalography in stroke: a 1-year follow-up study

Recovery after stroke is closely linked to cerebral plasticity. Magnetoencephalography (MEG) is a non-invasive technique, which allows location of cerebral cells activities. In the present work, a cohort of patients has been studied with MEG. Twelve patients with a recent ischemic or hemorragic stroke were included as soon as possible after onset of stroke. Neurologic assessment, including standard neurologic examination, functional independence measure (FIM) and Orgogozo's scale was performed for 1 year in addition to a study of the somatosensory evoked field (SEF) using a 37-channel Biomagnetometer system. No response could be recorded in five patients at the first SEF exploration. In three cases, no response was ever recorded during the study. All these patients had a bad recovery. The location of the SEF sources was always in the normal non-infarcted cortex of the postcentral gyrus. Sensory recovery seemed to be linked to the reorganization of the persistent functional cortex, which was a limiting factor for recovery. These observations confirm the experimental results obtained in animal models. After stroke it can be assumed that in the case of incomplete lesion, an intensive sensory peripheral stimulation could maximize the use of residual sensory function and then contribute to improve the sensory deficit. In case of total sensory loss other techniques have to be used, such as visual monitoring of hand activity in order to improve hand function.     

Hereditary motor and sensory neuropathy caused by a novel mutation in LITAF

Hereditary motor-sensory neuropathy (HMSN) Type 1/CMT 1 is a disorder of the peripheral nervous system. The underlying genetic cause is heterogeneous, and mutations in LITAF (Lipopolysaccharide-induced TNF-α factor) represent a rare cause of CMT Type 1. In this report, a novel missense mutation is presented in the LITAF gene (c.430G > A p.V144M) in a German CMT family exhibiting typical electrophysiological features of a demyelinating neuropathy with conduction blocks and variable age at onset. Molecular genetic characterization of demyelinating HMSN should therefore include screening of the LITAF gene if typical signs of a non-homogenous demyelinating neuropathy combined with dominant familial occurrence are evident.     

Central visual, acoustic, and motor pathway involvement in a Charcot-Marie-Tooth family with an Asn205Ser mutation in the connexin 32 gene

BACKGROUND: X linked dominant Charcot-Marie-Tooth disease (CMT1X) is an inherited motor and sensory neuropathy that mainly affects the peripheral nervous system. CMT1X is associated with mutations in the gap junction protein connexin 32 (Cx32). Cx32 is expressed in Schwann cells and oligodendrocytes in the peripheral (PNS) and in the (CNS) respectively. METHODS: A CMT1X family with a Cx32 mutation was examined clinically and electrophysiologically to determine whether PNS, or CNS, or both pathways were affected. RESULTS: In a CMT1X family a novel mutation (Asn205Ser) was found in the fourth transmembrane domain of Cx32. The patients showed typical clinical and electrophysiological abnormalities in the PNS, but in addition visual, acoustic, and motor pathways of the CNS were affected subclinically. This was indicated by pathological changes in visually evoked potentials (VEPs), brainstem auditory evoked potentials (BAEPs), and central motor evoked potentials (CMEPs). CONCLUSIONS: These findings underscore the necessity of a careful analysis of CNS pathways in patients with CMT and Cx32 mutations. Abnormal electrophysiological findings in CNS pathway examinations should raise the suspicion of CMTX and a search for gene mutations towards Cx32 should be considered.     

Bladder dysfunction in multiple sclerosis: a 6-year follow-up study

Bladder dysfunction (BD) is the most common autonomic disturbance in multiple sclerosis, but often overlooked and undertreated. The purpose of this longitudinal study was to explore the changes in the frequency of BD symptoms in MS cohort after a period of 3 and 6 years of follow-up, as well as to investigate the correlations between the presence of BD symptoms and both clinical characteristics and the health-related quality of life (HRQoL) at each subsequent point of estimation. The study population comprises a cohort of 93 patients with MS (McDonald’s criteria, 2001). At each time point (baseline, and at the 3- and 6-year follow-up) of estimation, Expanded Disability Status Scale, Hamilton Rating Scale for Depression, Fatigue Severity Scale, Szasz Sexual Functioning Scale and HRQoL (measured by MSQoL-54) were assessed. The proportion of patients with at least one symptom of BD significantly increased over time, for both men and women (from 48.1% at baseline to 51.9% after 3 years and to 71.4% after 6 years of follow-up for males and from 45.5% at baseline to 50.0% after 3 years and to 66.7% after 6 years of follow-up for females). The most common BD problem was urgency of urination. The presence of BD was statistically significantly associated with higher level of physical disability, sexual dysfunction and HRQoL at each point of follow-up, for both men and women. Our results suggested outstanding frequency of BD in patients with MS, with increasing tendency over time.     

细丝蛋白C肌病基因存在新的插入缺失突变

目的 报道在1个细丝蛋白C(filamin C,FLNC)肌病家系中发现的新的插入缺失突变.方法 该家系连续5代共有19例患者,临床和病理资料在前期研究中已经作为肌原纤维肌病进行了报道.现对包括先证者在内的3例患者、5名无症状家系成员和50名健康人进行FLNC基因的测序,利用质粒将FLNC基因的第18号外显子扩增产物进行克隆分离,然后进行电泳鉴定和直接测序.结果 先证者的FLNC基因的第18号外显子存在18个正常碱基缺失,同时插入6个异常碱基,导致FLNC蛋白第7个免疫球蛋白样杆状重叠结构异常,继而致FLNC蛋白结构的失稳.家系中另2例患者存在同样的突变,而5名无症状家系成员和50名健康对照均正常.结论 FLNC肌病存在FLNC基因第18号外显子新的插入缺失突变,我们发现该病可以出现在德国之外的其他种族.     

Asymptomatic hereditary Alexander's disease caused by a novel mutation in GFAP

We report on a family with dominantly inherited asymptomatic Alexander's disease due to a novel Glial fibrillary acidic protein (GFAP) mutation. The proband, a 16-month-old boy, presented with megalocephaly and brain magnetic resonance imaging (MRI) showing the typical findings of Alexander's disease. Molecular analysis showed that he was a heterozygote of the L331P mutation of GFAP. His mother and sister, without megalocephaly or other neurological abnormalities, were also heterozygotes of the mutation and their brain magnetic resonance imaging showed mild changes in the caudates and deep frontal white matters. These results suggest the existence of a forme fruste of Alexander's disease. The L331P mutation may be associated with the mild phenotype of Alexander's disease. To elucidate the genotype-phenotype correlation in Alexander's disease, molecular diagnosis and MRI examination are required for many patients and their families.     

Charcot–marie–tooth disease with intermediate conduction velocities caused by a novel mutation in the MPZ gene

Charcot–Marie–Tooth (CMT) disease is a heterogeneous group of inherited sensory and motor neuropathies. Mutations in the gene that encodes for myelin protein zero (MPZ) can produce different phenotypes: CMT1 (with low conduction velocities), CMT2 (less frequent and with unaffected conduction velocities), and CMTID (with intermediate conduction velocities). We report a study of seven patients from a four‐generation family. All the affected members of the family had a typical CMT phenotype, but three of them had calf hypertrophy. The nerve conduction velocities (NCV) in all of them were between 35 and 43 m/s. Molecular study revealed the novel mutation Lys214Met in the MPZ gene. Molecular study of the MPZ gene would be useful in cases of CMT in families with intermediate NCV, especially if no mutations in the GJB‐1 gene are found or there is male‐to‐male transmission. Muscle Nerve, 2010