Objective:To investigate the clinical, phenotypic and genotypic features of hereditary hyperhomocysteinemia mainly involving the nervous system.Methods:The clinical data, physical examination, imaging results, blood-urine tandem mass spectrometry analysis and genetic results of 8 patients with hyperhomocysteinemia from the Department of Neurology of the Shanghai Sixth People′s Hospital Affiliated to Shanghai Jiao Tong University School of Medicine from September 2020 to December 2023 were collected, and the clinical, genetic features and pathogenic mechanisms of these patients were summarized and analyzed.Results:Among all the 8 patients (male∶female=5∶3), the age of onset was 7 to 74 (40.4±7.4) years. Seven had adult-onset and 1 had juvenile-onset, with various types of onset symptoms, including progressive stiffness in lower limbs and walking difficulty, limb numbness, tremor, mental and behavioral abnormalities, cerebrovascular events, etc. Moderate to severe hyperhomocysteine (38.4-190.6 μmol/L) was present in all patients at first diagnosis. Among the 5 patients with cranial imaging examinations, all had white matter lesions. The genetic testing showed 7 patients with MTHFR gene pathogenic mutations (1 case with c.416C>T, and 6 cases with c.665C>T), and 1 patient with MMACHC gene pathogenic mutation (c.482G>A). Conclusions:Hereditary hyperhomocysteinemia is a metabolic disease, with complicated manifestations, varying degrees of severity, and diverse pathogenic genes. The cases with neurological involvement are not rare, such as spastic paraplegia-like manifestations, tremor, peripheral neuropathy, mental and behavioral abnormalities, cerebrovascular events.

Objective:To investigate the clinical, phenotypic and genotypic features of hereditary hyperhomocysteinemia mainly involving the nervous system.Methods:The clinical data, physical examination, imaging results, blood-urine tandem mass spectrometry analysis and genetic results of 8 patients with hyperhomocysteinemia from the Department of Neurology of the Shanghai Sixth People′s Hospital Affiliated to Shanghai Jiao Tong University School of Medicine from September 2020 to December 2023 were collected, and the clinical, genetic features and pathogenic mechanisms of these patients were summarized and analyzed.Results:Among all the 8 patients (male∶female=5∶3), the age of onset was 7 to 74 (40.4±7.4) years. Seven had adult-onset and 1 had juvenile-onset, with various types of onset symptoms, including progressive stiffness in lower limbs and walking difficulty, limb numbness, tremor, mental and behavioral abnormalities, cerebrovascular events, etc. Moderate to severe hyperhomocysteine (38.4-190.6 μmol/L) was present in all patients at first diagnosis. Among the 5 patients with cranial imaging examinations, all had white matter lesions. The genetic testing showed 7 patients with MTHFR gene pathogenic mutations (1 case with c.416C>T, and 6 cases with c.665C>T), and 1 patient with MMACHC gene pathogenic mutation (c.482G>A). Conclusions:Hereditary hyperhomocysteinemia is a metabolic disease, with complicated manifestations, varying degrees of severity, and diverse pathogenic genes. The cases with neurological involvement are not rare, such as spastic paraplegia-like manifestations, tremor, peripheral neuropathy, mental and behavioral abnormalities, cerebrovascular events.

A case of small cerebral vascular disease and moderate hyperhomocysteinemia caused by methylenetetrahydrofolate reductase gene mutation is reported.The patient was a 61-year-old man who presented with tongue stiffness and slurred speech,bilateral hand numbness and lower limb weakness.He had a history of recurrent cerebral infarction,cerebral hemorrhage,accompanied by leukoencephalopathy and cerebral microhemorrhage etc.Blood homocysteine(Hcy)66.2 μmol/L.Head magnetic resonance imaging revealed subacute cerebral infarction and white matter lesions in right parieto-occipital lobe and left pressor corpus callosum.The skin pathology showed normal density of small fibers,infiltration of perivasculitis cells in the epidermis and dermis,and swelling of endothelial cells in a wide range of small vessels in the dermis.Whole exon sequencing indicated homozygous pathogenic mutation of MTHFR gene c.665C>T(p.A222V).After 1 month of treatment,Hcy decreased to 20.5 μmol/L.This report suggests that HHcy is not only associated with leucoencephalopathy,but also can lead to skin small vessel lesions.Attention should be paid to peripheral vascular screening in this population for early intervention of potential risks.

A case of small cerebral vascular disease and moderate hyperhomocysteinemia caused by methylenetetrahydrofolate reductase gene mutation is reported.The patient was a 61-year-old man who presented with tongue stiffness and slurred speech,bilateral hand numbness and lower limb weakness.He had a history of recurrent cerebral infarction,cerebral hemorrhage,accompanied by leukoencephalopathy and cerebral microhemorrhage etc.Blood homocysteine(Hcy)66.2 μmol/L.Head magnetic resonance imaging revealed subacute cerebral infarction and white matter lesions in right parieto-occipital lobe and left pressor corpus callosum.The skin pathology showed normal density of small fibers,infiltration of perivasculitis cells in the epidermis and dermis,and swelling of endothelial cells in a wide range of small vessels in the dermis.Whole exon sequencing indicated homozygous pathogenic mutation of MTHFR gene c.665C>T(p.A222V).After 1 month of treatment,Hcy decreased to 20.5 μmol/L.This report suggests that HHcy is not only associated with leucoencephalopathy,but also can lead to skin small vessel lesions.Attention should be paid to peripheral vascular screening in this population for early intervention of potential risks.

Background: and Purpose X-linked Charcot-Marie-Tooth disease type 1 (CMTX1) is characterized by peripheral neuropathy with or without episodic neurological dysfunction. We performed clinical, neuropathological, and genetic investigations of a series of patients with mutations of the gap-junction beta-1 gene (GJB1) to extend the phenotypic and genetic description of CMTX1. Methods: Detailed clinical evaluations, sural nerve biopsy, and genetic analysis were applied to patients with CMTX1. Results: We collected 27 patients with CMTX1 with GJB1 mutations from 14 unrelated families. The age at onset (AAO) was 20.9±12.2 years (mean±standard deviation; range, 2–45 years). Walking difficulties, weakness in the legs, and pes cavus were common initial symptoms. Compared with female patients, males tended to have a younger AAO (males vs. females=15.4±9.6 vs. 32.0±8.8 years, p=0.002), a longer disease course (16.8±16.1 vs. 5.5±3.8 years, p=0.034), and more-severe electrophysiological results. Besides peripheral neuropathy, six of the patients had special episodic central nervous system (CNS) evidence from symptoms, signs, and/or reversible white-matter lesions. Neuropathology revealed the loss of large myelinated fibers, increased number of regenerated axon clusters with abnormally thin myelin sheaths, and excessively folded myelin. Genetic analysis identified 14 GJB1 variants, 6 of which were novel. Conclusions These findings expand the phenotypic and genetic spectrum of CMTX1. Although CMTX1 was found to have high phenotypic and CNS involvement variabilities, detailed neurological examinations and nerve conduction studies will provide critical clues for accurate diagnoses. Further exploration of the underlying mechanisms of connexin 32 involvement in neuropathy or CNS dysfunction is warranted to develop promising therapies.

Tubular aggregates(TA)are ultrastructural abnormalities in muscle biopsies,which can be detected in muscle biopsy specimens from patients with a variety of hereditary and acquired disorders.A 34-year-old male patient diagnosed with systemic lupus erythematosus(SLE)presented with intermittent muscle weakness localized to the proximal extremities of both lower limbs during prolonged oral administration of methylprednisolone,hydroxychloroquine and tacrolimus.Laboratory findings indicated normal creatine kinase levels,and anti-U1-RNP/Sm antibodies were elevated up to 49.45 RU/mL.Electromyography revealed myogenic lesions in the left iliopsoas muscle and muscle pathology demonstrated TA within the muscle fibers.Genetic testing excluded the possibility of hereditary disorders with tubular aggregas.Combined with literature review,the etiology and clinical characteristics of TA were discussed to increase the understanding of the diagnosis of diseases with TA.This case report demonstrates that SLE patients can have fluctuating muscle weakness and TA in muscle pathology.The symptoms of SLE can be partially relieved by adjusting SLE medications.

Objective:To summarize and analyze the clinical data of Chinese patients with colony-stimulating factor 1 receptor (CSF1R)-related leukoencephalopathy, and clarify the phenotypic and genetic characteristics of Chinese patients.Methods:Medical history of patients with CSF1R-related leukoencephalopathy diagnosed from April 1, 2018 to January 31, 2021 in the department of neurology of 22 hospitals in China was collected, and scores of Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment Scale (MoCA), magnetic resonance severity scale were evaluated. Group comparison was performed between male and female patients.Results:A total of 62 patients were included, and the male-female ratio was 1∶1.95. The age of onset was (40.35±8.42) years. Cognitive impairment (82.3%, 51/62) and motor symptoms (77.4%,48/62) were the most common symptoms. The MMSE and MoCA scores were 18.79±7.16 and 13.96±7.23, respectively, and the scores of two scales in male patients (22.06±5.31 and 18.08±5.60) were significantly higher than those in females (15.53±7.41 , t=2.954, P=0.006; 10.15±6.26, t=3.328 , P=0.003). The most common radiographic feature was bilateral asymmetric white matter changes (100.0%), and the magnetic resonance imaging severity scale score was 27.42±11.40, while the white matter lesion score of females (22.94±8.39) was significantly higher than that of males (17.62±8.74 , t=-2.221, P<0.05). A total of 36 CSF1R gene mutations were found in this study, among which c.2381T>C/p.I794T was the hotspot mutation that carried by 17.9% (10/56) of the probands. Conclusions:The core phenotypic characteristics of CSF1R-related leukoencephalopathy in China are progressive motor and cognitive impairment, with bilateral asymmetrical white matter changes. In addition, there exist gender differences clinically, with severer cognitive impairment and imaging changes in female patients. Thirty-six CSF1R gene mutations were found in this study, and c.2381T>C/p. I794T was the hotspot mutation.

The skin is the largest organ comprised of three main layers: epidermis, dermis and subcutaneous tissue. Characteristic microscopic and ultrastructural alterations are present in certain skin structures, such as nerve fibers, blood vessels and sweat glands, not only in vasculitis, but in several other metabolic neurologic diseases. In recent years, advances in immunohistochemistry and electron microscopy have made these dermatopathological changes identifiable and clear-cut. It was then recognized that such pathological feature could be present in many tissues in addition to those nerve systems clinically affected. Skin biopsy has become a recognized diagnostic procedure for peripheral neuropathy and central nervous system diseases. This article reviews the dermatopathology in neurological disorders under light and electron microscope to promote application of skin biopsy in clinical diagnosis for neurologist.

ObjectivesTo report pathological and genetic features of 6 Chinese families with Xlinked Charcot-Marie-Tooth disease type 1 ( CMTX1 ).Methods The index cases from 6 families with CMTX1 are males with onset of disease between 11 and 24 years old.All of them had distal leg muscle weakness,accompanied with areflexia and sensory loss in the feet.Additionally,the index 1 presented with recurrent encephalopathy and the index case 5 with cerebellar ataxia.Peripheral neuropathy was found in 12 family members,while other 7 members showed talipescavus and hyporeflexia.Sural nerve biopsies were performed in all index cases.Connexin 32(Cx32) gene was analyzed in the index cases,8 affected and 10unaffected family members as well as 50 healthy women control subjects.ResultsMild to moderate loss of myelinated fiber with axonal degeneration and regeneration clusters were found in all index cases. Thin myelin fibers were found in 5,small onion bulbs in 3 and inflammatory infiltrates in 2.Five novel mutations (I20T,I127F,D178G,A197V,403_404insT) and one L10L synonymous mutation were detected in the 6index cases and their affected family members.The same mutations,in heterozygous state,were detected in 4 female family members without clinical symptoms,but not found in 6 male unaffected family members.The same mutations were not found in healthy control subjects.ConclusionsThe CMTX1 patients in our study present predominantly axonal lesions.Frequent novel Cx32 gene mutations indicated that private mutations may be common in Chinese CMTX1 patients.