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.

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 study the clinical features of two primary Sj?gren's syndrome(pSS)patients with neurological symptoms as initial manifestations and review the related literature.Methods·The clinical data,response to treatment as well as prognosis of 2 cases were analyzed and followed up.Results·Case 1,female,initially presented progressive gait instability and distal sensory impairment at the age of 50.Clinical manifestations included spastic gait,sensory ataxia,conduction fascicular sensory impairment,as well as urination and defecation dysfunction.At the age of 58,this patient was unable to walk independently.The laboratory findings revealed a positive result for anti-nuclear antibody with a titer of 1∶1 000,anti-Sj?gren's syndrome A(SSA)/Ro-52,anti-SSA/Ro-60,and anti-centromere antibodies.Labial salivary gland biopsy showed lymphocytes and plasma cells infiltration into the glandular tissues,interstitium,and lobules,with 2 foci/4 mm2(lymphocytes＞50).The cranial magnetic resonance imaging exhibited bilateral symmetric hyperintensity in the brainstem,characterized by the"snake-eye sign".Electromyography examination revealed axonal impairment of the right peroneal nerve.The patient was treated with high-dose corticosteroid therapy in combination with immunosuppressants.She experienced remarkable improvement.After three months,she was able to walk with aids and take care of herself in daily life.Case 2,female,presented spasmodic torticollis since the age of 81 with unknown reason.She had a history of mild mucosal dryness of mouth and eyes,and painful knee for one year.Laboratory findings revealed positive results for anti-SSA/Ro-52 and anti-SSA/Ro-60 antibodies,as well as hemoglobin of 86 g/L.Labial salivary gland biopsy demonstrated partial atrophy of the acini and the presence of 2 foci/4 mm2of lymphocytes and plasma cells infiltration into the stroma(lymphocytes＞50).Electromyography examination showed reduced conduction velocity in the right median nerve.She got a significant relief after the treatment of immunosuppressants,antispasmodics,and muscle relaxants.Conclusion·Patients presenting initial symptoms such as complex forms of spastic paraplegia and cervical dystonia expand the clinical spectrum of pSS.In clinical practice,it is important to distinguish neurological involvement secondary to pSS from other primary neurological disorders.For patients with neurological impairments but without apparent etiology,it is crucial to screen relevant series of autoimmune antibodies.

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.

Scavenger receptor class B, member 2 (SCARB2) is linked to Gaucher disease and Parkinson's disease. Deficiency in the SCARB2 gene causes progressive myoclonus epilepsy (PME), a rare group of inherited neurodegenerative diseases characterized by myoclonus. We found that Scarb2 deficiency in mice leads to age-dependent dietary lipid malabsorption, accompanied with vitamin E deficiency. Our investigation revealed that Scarb2 deficiency is associated with gut dysbiosis and an altered bile acid pool, leading to hyperactivation of FXR in intestine. Hyperactivation of FXR impairs epithelium renewal and lipid absorption. Patients with SCARB2 mutations have a severe reduction in their vitamin E levels and cannot absorb dietary vitamin E. Finally, inhibiting FXR or supplementing vitamin E ameliorates the neuromotor impairment and neuropathy in Scarb2 knockout mice. These data indicate that gastrointestinal dysfunction is associated with SCARB2 deficiency-related neurodegeneration, and SCARB2-associated neurodegeneration can be improved by addressing the nutrition deficits and gastrointestinal issues.
Animals ; Mice ; Dysbiosis/metabolism* ; Mice, Knockout ; Humans ; Lysosomal Membrane Proteins/genetics* ; Receptors, Scavenger/genetics* ; Gastrointestinal Microbiome ; Myoclonic Epilepsies, Progressive/genetics* ; Vitamin E Deficiency/complications* ; Neurodegenerative Diseases/genetics* ; Bile Acids and Salts/metabolism* ; Male ; Lipid Metabolism ; Intestinal Mucosa/pathology*

Objective:To report 8 cases of hereditary spastic paraplegia type 35 (SPG35) in Chinese mainland, summarize the clinical and genetic features of this disease.Methods:Eight probands with SPG35, admitted in Shanghai Jiao Tong University Affiliated Sixth People′s Hospital and Ruijin Hospital, Shanghai Jiao Tong University School of Medicine from September 2006 to June 2021, were collected in detail. Physical examination, cranial imaging examination and whole exome sequencing were conducted, followed by Sanger sequencing and family co-segregation. In addition, the recent advances in clinical, genetic and pathogenesis studies of the disease were also reviewed.Results:Among all of the 8 patients, 7 had juvenile-onset and 1 was adult-onset. The clinical phenotype of 2 cases was pure spastic paraplegia. The other 6 cases presented with complicated form, which was characterized by not only motor dysfunction, but also cognitive impairment and dysphagia, etc. Genetic testing revealed a total of 13 fatty acid 2-hydroxylase (FA2H) gene (NM_024306) mutations, of which 6 were reported and 7 were newly reported in this study.Conclusions:SPG35 is an autosomal recessive neurodegenerative disease with highly phenotypic heterogeneity, with the causative gene as FA2H. The genotype-phenotype correlations in SPG35 are not clear.

Objective:To investigate the clinical and genetic characteristics of patients with late-onset subtypes (adolescent or adult) of Krabbe disease.Methods:The clinical data of 7 patients with Krabbe disease admitted to Shanghai Jiao Tong University Affiliated Sixth People′s Hospital and Ruijin Hospital, Shanghai Jiao Tong University School of Medicine from September 2006 to June 2021 were analyzed and Sanger sequencing of the galactosylceramidase (GALC) gene (NM_000153) and detection of the activity of GALC were conducted. A total of 61 cases of Krabbe disease reported in domestic literature were reviewed and summarized.Results:Among the 7 patients with Krabbe disease, there were 4 males and 3 females. All of them had lower limb weakness or walking difficulty as the initial symptoms, and presented as spastic paraplegia. The symptoms were relatively mild in patients with late onset. There were 4 out of 5 patients undergoing magnetic resonance imaging examination, who showed abnormal signals: 2 had brain atrophy and the remaining 2 had white matter lesions. A total of 5 GALC gene mutations were detected by genetic analysis. Among these, c.1901T>C (p.L634S), c.908C>T(p.S303F) and c.461C>A(p.P154H) are known variants, while c.50_51insTT (p.M17Ifs) and c.1130delT(p.L337X) are novel variants reported for the first time in this paper.Conclusions:Krabbe disease is a rare neurodegenerative disease with phenotypic heterogeneity, which is inherited in an autosomal recessive mode. The severity of clinical manifestations of Krabbe disease is correlated with the age of onset.

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.