•We identified an ataxia case of peroxisomal disorders caused by novel compound heterozygous mutations of the PEX10 gene.•We report the first Chinese patient with PEX10-related peroxisomal ...disorders.•We review PEX10–related peroxisomal disorders, of which 31 various mutations have been reported.
To describe the clinical and genetic features of a Chinese peroxisome biogenesis disorder 6B patient with PEX10 mutations and review PEX10–related peroxisomal disorders.
The proband is a 7-year-old boy with mild mental retardation and gait instability, intention tremor and nystagmus. An extensive clinical and laboratory evaluation including molecular genetic studies was performed. Genomic DNA was extracted from peripheral blood using the standardized phenol/chloroform extraction method, and the coding region of the PEX10 gene was sequenced in three family members.
Cerebral MRI showed cerebellar atrophy. Magnetic resonance spectroscopy revealed a decreased N-acetyl aspartate peak in the cerebellum. Nerve conduction velocity examination found prolonged motor and sensory nerve potential latencies (proximal obvious), decreased potential amplitude, and slow nerve conduction velocity. Routine blood tests and biochemistries were abnormal. The PEX10 gene test showed compound heterozygous mutations (c.209 G > A, p. G70E and c.830 T > C, p. L277 P). The mutation c.830 T > C, p. L277 P has been previously reported, whereas c.209 G > A, p. G70E is novel.
We identified an ataxia case of peroxisome biogenesis disorder 6B caused by novel compound heterozygous mutations of the PEX10 gene. Peroxisome biogenesis disorders should be considered in the differential diagnosis of autosomal recessive ataxia, especially cases with early onset.
CSF1R
-related leukoencephalopathy is a rare white-matter encephalopathy characterized by motor and neuropsychiatric symptoms due to colony-stimulating factor 1 receptor (
CSF1R
) gene mutation. Few ...studies have investigated the intrinsic brain alternations of patients with
CSF1R
-related leukoencephalopathy. We aim to evaluate the structural and functional changes in those patients. Seven patients with
CSF1R
-related leukoencephalopathy and 15 age-matched healthy controls (HCs) underwent multimodal magnetic resonance imaging (MRI), including high-resolution T1-weighted imaging, T2-weighted fluid attenuated inversion recovery imaging, diffusion-weighted imaging, diffusion kurtosis imaging (DKI) and resting-state functional MRI. First, to detect structural alterations, the gray matter volumes were compared using voxel-based morphometry analyses. Second, DKI parametric maps were used to evaluate the white matter (WM) connectivity changes. Finally, we constructed a seed-based resting-state functional connectivity matrix based on 90 regions of interest and examined the functional network changes of
CSF1R
-related leukoencephalopathy. Unlike the HCs, patients with
CSF1R
-related leukoencephalopathy predominantly had morphological atrophy in the bilateral thalamus and left hippocampus. In addition, the abnormal diffusivity was mainly distributed in the splenium of the corpus callosum, periventricular regions, centrum semiovale, subcortical U-fibers and midline cortex structures. Moreover, the patients had significantly reduced functional connectivity between the bilateral caudate nucleus and their contralateral hippocampus. Therefore, in addition to hyperintensity on the T2-weighted images,
CSF1R
-related leukoencephalopathy also showed abnormal structural and functional alterations, including subcortical atrophy and reduced functional connectivity, as well as altered diffuse parameters in the WM and subcortical regions. These findings expand our understanding of the potential pathophysiologic mechanism behind this hereditary disease.
Hereditary spastic paraplegia type 18 （HSP18） is a complicated form ofautosomal recessive HSP characterized by progressive weakness and spasticity of the lower extremities,dysarthria,and cognitive ...decline. In the year 2011,HSP18,also known as Spastic Paraplegia 18 （SPG18）,was firstly identified due to a candidate gene endoplasmic reticulum lipid raft-associated protein 2 （ERLIN2） on chromosome 8pl 1.2 in one Saudis family.During the past 5 years,another two families with SPG18 due to ERLIN2 mutations have been reported presenting with complicated phenotype. Here,we reported a patient born in a nonconsanguineous family who possessed an autosomal recessive pure form of HSP owing to novel mutations in ERLIN2.Patient was characterized by late-onset spasticity of lower extremities without significant speech involvement or cognitive disability.
...warm-up phenomena and grips myotonia were demonstrated. ...the limb muscle tone increased obviously. ...she possessed strabismus of the right eye Figure 1e, slurred speech and weak voice, claw ...finger deformity, and strephenopodia. ...p.P1158A in SCN4A wasfirst explored in our patients with MC.
Objective
GDP‐mannose pyrophosphorylase B (GMPPB) related phenotype spectrum ranges widely from congenital myasthenic syndrome (CMS), limb‐girdle muscular dystrophy type 2T (LGMD 2T) to severe ...congenital muscle‐eye‐brain syndrome. Our study investigates the clinicopathologic features of a patient with novel GMPPB mutations and explores the pathogenetic mechanism.
Methods
The patient was a 22‐year‐old woman with chronic proximal limb weakness for 9 years without cognitive deterioration. Weakness became worse after fatigue. Elevated serum creatine kinase and decrements on repetitive nerve stimulation test were recorded. MRI showed fatty infiltration in muscles of lower limbs and shoulder girdle on T1 sequence. Open muscle biopsy and genetic analysis were performed.
Results
Muscle biopsy showed myogenic changes. Two missense mutations in GMPPB gene (c.803T>C and c.1060G>A) were identified in the patient. Western blotting and immunostaining showed GMPPB and α‐dystroglycan deficiency in the patient's muscle. In vitro, mutant GMPPB forming cytoplasmic aggregates completely colocalized with microtubule‐associated protein 1 light chain 3‐II (LC3‐II), a classical marker of autophagosome. Degradation of GMPPB was accompanied by an upregulation of LC3‐II, which could be restored by lysosomal inhibitor leupeptin.
Interpretation
We identified two novel GMPPB mutations causing overlap phenotype between LGMD 2T and CMS. We provided the initial evidence that mutant GMPPB colocalizes with autophagosome at subcellular level. GMPPB mutants degraded by autophagy‐lysosome pathway is associated with LGMD 2T. This study shed the light into the enzyme replacement which could become one of the therapeutic targets in the future study.
-related leukoencephalopathy, also known as hereditary diffuse leukoencephalopathy with spheroids (HDLS), is a rare white-matter encephalopathy characterized by motor and neuropsychiatric symptoms ...due to colony-stimulating factor 1 receptor (
) gene mutation. Few of
mutations have been functionally testified and the pathogenesis remains unknown.
In order to investigate clinical and pathological characteristics of patients with
-related leukoencephalopathy and explore the potential impact of
mutations, we analyzed clinical manifestations of 15 patients from 10 unrelated families and performed brain biopsy in 2 cases. Next generation sequencing was conducted for 10 probands to confirm the diagnosis. Sanger sequencing, segregation analysis and phenotypic reevaluation were utilized to substantiate findings. Functional examination of identified mutations was further explored.
Clinical and neuroimaging characteristics were summarized. The average age at onset was 35.9 ± 6.4 years (range 24-46 years old). Younger age of onset was observed in female than male (34.2 vs. 39.2 years). The most common initial symptoms were speech dysfunction, cognitive decline and parkinsonian symptoms. One patient also had marked peripheral neuropathy. Brain biopsy of two cases showed typical pathological changes, including myelin loss, axonal spheroids, phosphorylated neurofilament and activated macrophages. Electron microscopy disclosed increased mitochondrial vacuolation and disorganized neurofilaments in ballooned axons. A total of 7 pathogenic variants (4 novel, 3 documented) were identified with autophosphorylation deficiency, among which c.2342C > T remained partial function of autophosphorylation. Western blotting disclosed the significantly lower level of c.2026C > T (p.R676*) than wild type. The level of microtubule associated protein 1 light chain 3-II (LC3-II), a classical marker of autophagy, was significantly lower in mutants expressed cells than wild type group by western blotting and immunofluorescence staining.
Our findings support the loss-of-function and haploinsufficiency hypothesis in pathogenesis. Autophagy abnormality may play a role in the disease. Repairing or promoting the phosphorylation level of mutant CSF1R may shed light on therapeutic targets in the future. However, whether peripheral polyneuropathy potentially belongs to
-related spectrum deserves further study with longer follow-up and more patients enrolled.
ChiCTR, ChiCTR1800015295. Registered 21 March 2018.
Objective
To describe the clinical and genetic features of two patients with different phenotypes due to various Dynactin 1 (DCTN1) gene mutations and further explore the phenotype–genotype ...relationship.
Methods
Patient 1 is a 23‐year‐old man with congenital foot deformity and life‐long distal muscle weakness and atrophy. Patient 2 is a 48‐year‐old woman with adult‐onset progressive weakness, lower limbs atrophy, and pyramid bundle signs. Electrophysiology test showed normal nerve conduction velocity of both patients and neurogenic changes in needle electromyography. Open sural nerve biopsy for Patient 1 showed slight loss of myelinated nerve fibers. Both patients were performed with whole‐exome sequencing followed by functional study of identified variants.
Results
Two mutations in DCTN1 gene were identified in Patient 1 (c.626dupC) and Patient 2 (c.3823C>T), respectively. In vitro, the wild type mostly located in cytoplasm and colocalized with α‐tubulin. However, c.626dupC tended to be trapped into nuclear and the c.3823C>T formed cytoplasmic aggregates, both losing colocalization with α‐tubulin. Western blotting showed a truncated mutant with less molecular weight of c.626dupC was expressed.
Interpretation
We identify two novel DCTN1 mutations causing different phenotypes: (1) early‐onset distal hereditary motor neuropathy plus congenital foot malformation and (2) amyotrophic lateral sclerosis, respectively. We provide the initial evidence that foot developmental deficiency probably arises from subcellular localizing abnormality of Dynactin 1, revealing DCTN1‐related spectrum is still expanding.
Paroxysmal kinesigenic dyskinesia (PKD) is a rare movement disorder characterized by recurrent dystonic or choreoathetoid attacks triggered by sudden voluntary movements. Under the condition of ...psychological burden, some patients' attacks may get worsened with longer duration and higher frequency. This study aimed to assess nonmotor symptoms and quality of life of patients with PKD in a large population.
We performed a cross-sectional survey in 165 primary PKD patients from August 2008 to October 2016 in Rui Jin Hospital, using Symptom Check List-90-Revised (SCL-90-R), World Health Organization Quality of Life-100 (WHOQoL-100), Self-Rating Depression Scale, and Self-Rating Anxiety Scale. We evaluated the differences of SCL-90-R and WHOQOL-100 scores in patients and Chinese normative data (taken from literature) by using the unpaired Student's t-test. We applied multivariate linear regression to analyze the relationships between motor manifestations, mental health, and quality of life among PKD patients.
Compared with Chinese normative data taken from literature, patients with PKD exhibited significantly higher (worse) scores across all SCL-90-R subscales (somatization, obsessive-compulsive, interpersonal sensitivity, depression, anxiety, hostility, phobic anxiety, paranoid ideation, and psychoticism; P= 0.000 for all) and significantly lower (worse) scores of five domains in WHOQoL-100 (physical domain, psychological domain, independence domain, social relationship domain, and general quality of life; P= 0.000 for all). Nonremission of dyskinesia episodes (P = 0.011) and higher depression score (P = 0.000) were significantly associated with lower levels of quality of life. The rates of depression and anxiety in patients with PKD were 41.2% (68/165) and 26.7% (44/165), respectively.
Depression, anxiety, and low levels of quality of life were prevalent in patients with PKD. Co-occurrence of depression and anxiety was common among these patients. Regular mental health interventions could set depression and anxiety as intervention targets. Considering that the motor episodes could be elicited by voluntary movements and sometimes also by emotional stress, and that symptoms may get worsened with longer duration and higher frequency when patients are stressed out, intervention or treatment of depression and anxiety might improve the motor symptoms and overall quality of life in PKD patients.
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