Background:Large language models (LLMs) are increasingly used in the medical field for diverse applications including differential diagnostic support. The estimated training data used to create LLMs such as the Generative Pretrained Transformer (GPT) predominantly consist of English-language texts, but LLMs could be used across the globe to support diagnostics if language barriers could be overcome. Initial pilot studies on the utility of LLMs for differential diagnosis in languages other than English have shown promise, but a large-scale assessment on the relative performance of these models in a variety of European and non-European languages on a comprehensive corpus of challenging rare-disease cases is lacking. Methods:We created 4967 clinical vignettes using structured data captured with Human Phenotype Ontology (HPO) terms with the Global Alliance for Genomics and Health (GA4GH) Phenopacket Schema. These clinical vignettes span a total of 378 distinct genetic diseases with 2618 associated phenotypic features. We used translations of the Human Phenotype Ontology together with language-specific templates to generate prompts in English, Chinese, Czech, Dutch, German, Italian, Japanese, Spanish, and Turkish. We applied GPT-4o, version gpt-4o-2024-08-06, to the task of delivering a ranked differential diagnosis using a zero-shot prompt. An ontology-based approach with the Mondo disease ontology was used to map synonyms and to map disease subtypes to clinical diagnoses in order to automate evaluation of LLM responses. Findings:For English, GPT-4o placed the correct diagnosis at the first rank 19·8% and within the top-3 ranks 27·0% of the time. In comparison, for the eight non-English languages tested here the correct diagnosis was placed at rank 1 between 16·9% and 20·5%, within top-3 between 25·3% and 27·7% of cases. Interpretation:The differential diagnostic performance of GPT-4o across a comprehensive corpus of rare-disease cases was consistent across the nine languages tested. This suggests that LLMs such as GPT-4o may have utility in non-English clinical settings. Funding:NHGRI 5U24HG011449 and 5RM1HG010860. P.N.R. was supported by a Professorship of the Alexander von Humboldt Foundation; P.L. was supported by a National Grant (PMP21/00063 ONTOPRECISC-III, Fondos FEDER).

BackgroundNon-motor symptoms (NMS) are compulsory clinical features for the clinical diagnosis of multiple system atrophy (MSA), some of which precede motor symptoms onset. To date, few studies have systematically investigated NMS in MSA and the timing of presenting NMS as the disease progresses. Clinically, MSA is difficult to be differentiated from Parkinson's disease (PD) and progressive supranuclear palsy (PSP), and the differences in NMS between MSA and PD/PSP remain unclear. The aim of this study was to compare the burden of NMS between MSA and PD/PSP and to delineate the timing of NMS presentation relative to the onset of motor symptoms in MSA.MethodsA total of 61, 87, and 30 patients with MSA, PD, and PSP, respectively, were enrolled in this study. NMS was systematically assessed in all patients using the NMS scale (NMSS), and the onset of NMS relative to the onset of motor symptoms in MSA was investigated.ResultsMSA group had higher total NMSS scores (82.15 ± 46.10) than the PD (36.14 ± 30.78) and PSP (50.30 ± 55.05) groups (p < 0.001 overall). The number distribution pattern of the NMS was significantly different among the three parkinsonian disorders (p < 0.001 overall). In total, 85.2% of patients with MSA had more than 10 NMS, which was significantly higher than PD (28.7%) and PSP (33.3%). The frequency and scores of many NMSS subdomains and symptoms were higher in MSA than in PD and PSP (all p < 0.05). Multivariate logistic regression analysis revealed that patients with fainting, lack of motivation, swallowing, and loss of sexual interest could be attributed to MSA rather than PD or PSP, while patients with loss of concentration and forgetfulness were characteristic features of PD or PSP rather than MSA. REM-sleep behavior disorder (RBD), constipation, problems having sex, and loss of sexual interest preceded the motor symptoms onset of MSA by 2.81 ± 4.51, 1.54 ± 6.32, 1.35 ± 4.70, and 0.45 ± 3.61 years, respectively.ConclusionThe NMS spectrum in MSA differs from that of PD and PSP. Patients with MSA have a higher NMS burden than patients with PD or PSP. RBD, constipation, problems having sex, and loss of sexual interest may become early diagnostic clinical markers of MSA.

To elucidate the molecular basis of multiple system atrophy (MSA), a neurodegenerative disease, we conducted a genome-wide association study (GWAS) in a Japanese MSA case/control series followed by replication studies in Japanese, Korean, Chinese, European and North American samples. In the GWAS stage rs2303744 on chromosome 19 showed a suggestive association ( P = 6.5 × 10 -7 ) that was replicated in additional Japanese samples ( P = 2.9 × 10 -6 . OR = 1.58; 95% confidence interval, 1.30 to 1.91), and then confirmed as highly significant in a meta-analysis of East Asian population data ( P = 5.0 × 10 -15 . Odds ratio= 1.49; 95% CI 1.35 to 1.72). The association of rs2303744 with MSA remained significant in combined European/North American samples ( P =0.023. Odds ratio=1.14; 95% CI 1.02 to 1.28) despite allele frequencies being quite different between these populations. rs2303744 leads to an amino acid substitution in PLA2G4C that encodes the cPLA2γ lysophospholipase/transacylase. The cPLA2γ-Ile143 isoform encoded by the MSA risk allele has significantly decreased transacylase activity compared with the alternate cPLA2γ-Val143 isoform that may perturb membrane phospholipids and α-synuclein biology.

Paroxysmal dyskinesias are a group of neurological diseases characterized by intermittent episodes of involuntary movements with different causes. Paroxysmal kinesigenic dyskinesia (PKD) is the most common type of paroxysmal dyskinesia and can be divided into primary and secondary types based on the etiology. Clinically, PKD is characterized by recurrent and transient attacks of involuntary movements precipitated by a sudden voluntary action. The major cause of primary PKD is genetic abnormalities, and the inheritance pattern of PKD is mainly autosomal-dominant with incomplete penetrance. The proline-rich transmembrane protein 2 ( PRRT2 ) was the first identified causative gene of PKD, accounting for the majority of PKD cases worldwide. An increasing number of studies has revealed the clinical and genetic characteristics, as well as the underlying mechanisms of PKD. By seeking the views of domestic experts, we propose an expert consensus regarding the diagnosis and treatment of PKD to help establish standardized clinical evaluation and therapies for PKD. In this consensus, we review the clinical manifestations, etiology, clinical diagnostic criteria and therapeutic recommendations for PKD, and results of genetic analyses in PKD patients performed in domestic hospitals.

BACKGROUND:Charcot-Marie-Tooth (CMT) disease is an exciting field of study, with a growing number of causal genes and an expanding phenotypic spectrum. The microrchidia family CW-type zinc finger 2 gene (MORC2) was newly identified as a causative gene of CMT2Z in 2016. We aimed to describe the phenotypic-genetic spectrum of MORC2-related diseases in the Chinese population.METHODS:With the use of Sanger sequencing and Next Generation Sequencing (NGS) technologies, we screened a cohort of 284 unrelated Chinese CMT2 families. Pathogenicity assessments of MORC2 variants were interpreted according to the ACMG guidelines. Potential pathogenic variants were confirmed by Sanger sequencing.RESULTS:We identified 4 different heterozygous MORC2 mutations in four unrelated families, accounting for 1.4% (4/284). A novel mutation c.1397A>G p. D466G was detected in family 1 and all affected patients presented with later onset axonal CMT with hyperCKemia. The patient in family 2 showed a spinal muscular atrophy (SMA)-like disease with cerebellar hypoplasia and mental retardation, with a hot spot de novo mutation c.260C>T p. S87L. The twin sisters in family 3 were identified as having the most common mutation c.754C>T p. R252W and suffered from axonal motor neuropathy with high variability in disease severity and duration. The patient in family 4 developed an early onset axonal motor and sensory neuropathy, with a reported mutation c.1220G>A p.C407Y. All identified mutations associated with MORC2-related neuropathies are localized in the N-terminal ATPase module.CONCLUSIONS:Our study confirmed that MORC2-related neuropathies exist in the Chinese population at a relatively high mutation rate. We revealed a complex genotype-phenotype correlation with MORC2 mutations. This report adds a new piece to the puzzle of the genetics of CMT and contributes to a better understanding of the disease mechanisms.

Emerging evidence indicates that gut dysbiosis may play a regulatory role in the onset and progression of Huntington’s disease (HD). However, any alterations in the fecal microbiome of HD patients and its relation to the host cytokine response remain unknown. The present study investigated alterations and host cytokine responses in patients with HD. We enrolled 33 HD patients and 33 sex- and age- matched healthy controls. Fecal microbiota communities were determined through 16S ribosomal DNA gene sequencing, from which we analyzed fecal microbial richness, evenness, structure, and differential abundance of individual taxa between HD patients and healthy controls. HD patients were evaluated for their clinical characteristics, and the relationships of fecal microbiota with these clinical characteristics were analyzed. Plasma concentrations of interferon gamma (IFN-γ), interleukin 1 beta (IL-1β), IL-2, IL-4, IL-6, IL-8, IL-10, IL-12p70, IL-13, and tumor necrosis factor alpha were measured by Meso Scale Discovery (MSD) assays, and relationships between microbiota and cytokine levels were analyzed in the HD group. HD patients showed increased α-diversity (richness), β-diversity (structure), and altered relative abundances of several taxa compared to those in healthy controls. HD-associated clinical characteristics correlated with the abundances of components of fecal microbiota at the genus level. Genus Intestinimonas was correlated with total functional capacity scores and IL-4 levels. Our present study also revealed that genus Bilophila were negatively correlated with proinflammatory IL-6 levels. Taken together, our present study represents the first to demonstrate alterations in fecal microbiota and inflammatory cytokine responses in HD patients. Further elucidation of interactions between microbial and host immune responses may help to better understand the pathogenesis of HD.

Objective:To investigate the clinical and genetic characteristics of patients with CTA/CTG trinucleotide repeat expansion of ATXN8OS gene.Methods:The CTA/CTG trinucleotide repeats of ATXN8OS gene were detected in 1 689 spinocerebellar ataxia cases from Research Center for Movement Disorders and Neurogenetics, Department of Neurology, China-Japan Friendship Hospital in 2005—2017. The correlation between clinical phenotypes and expanded CTA/CTG repeats in the ATXN8OS gene of patients was studied carefully, and compared with 100 healthy controls.Results:Twenty-one patients with pathological CTA/CTG repeat expansion of ATXN8OS gene were collected. Eighteen of them carried the alleles with more than 80 repeats, whose common initial symptom was gait instability, followed by dysarthria and dysphagia with disease progression. Four of the 18 patients presented with head or truncal tremor. The other three patients carried the alleles with the repeats ranging from 70 to 79, whose initial symptom was walking instability, gradually appeared dysarthria, with no dysphagia or tremor. The repeat lengths ranged from 19 to 42 in the 100 healthy controls. The brain magnatic resonance imaging of almost all the patients showed moderate to severe cerebellar atrophy, and some patients with mild atrophy of the brainstem except one case with corpus callosum dysplasia.Conclusions:Most of the patients with CTA/CTG repeat expansion presented with ataxia and dysarthria. Brain magnetic resonance imaging showed significant cerebellar atrophy, suggesting that the mutation is related to SCA8 gene.

Pre-testing preparation is the basis and starting point of genetic testing.The process includes collection of clinical information,formulation of testing scheme,genetic counseling before testing,and completion of informed consent and testing authorization.To effectively identify genetic diseases in clinics can greatly improve the diagnostic rate of next generation sequencing (NGS),thereby reducing medical cost and improving clinical efficacy.The analysis of NGS results relies,to a large extent,on the understanding of genotype-phenotype correlations,therefore it is particularly important to collect and evaluate clinical phenotypes and describe them in uniform standard terms.Different types of genetic diseases or mutations may require specific testing techniques,which can yield twice the result with half the effort.Pre-testing genetic counseling can help patients and their families to understand the significance of relevant genetic testing,formulate individualized testing strategies,and lay a foundation for follow-up.

Clinical genetic testing results are compiled into a standardized report by genetic specialists and provided to clinicians and patients (Should the patient be intellectually disabled or under 18,the report will be provided to his/her parents or legal guardians).The content of genetic testing report should conform to relevant guidelines,industry standards and consensus.The decisions of clinicians will be made based on the report and clinical indications.Genetic counselors should provide post-test counseling to clinicians and patients or their authorized family members.A mechanism of follow-up visit after the genetic testing should be established with informed consent.Data should be shared by clinical institutions and genome sequencing institutions.As findings upon follow-up visit can help with further evaluation of the results,genome sequencing institutions should regularly re-analyze historical and follow-up data,and the updated results should be shared with clinical institutions.All activities involving reporting,genetic counselling,follow-up visiting,and re-analyzing should follow the relevant guidelines and regulations.

With high accuracy and precision,next generation sequencing (NGS) has provided a powerful tool for clinical testing of genetic diseases.To follow a standardized experimental procedure is the prerequisite to obtain stable,reliable,and effective NGS data for the assistance of diagnosis and/or screening of genetic diseases.At a conference of genetic testing industry held in Shanghai,May 2019,physicians engaged in the diagnosis and treatment of genetic diseases,experts engaged in clinical laboratory testing of genetic diseases and experts from third-party genetic testing companies have fully discussed the standardization of NGS procedures for the testing of genetic diseases.Experts from different backgrounds have provided opinions for the operation and implementation of NGS testing procedures including sample collection,reception,preservation,library construction,sequencing and data quality control.Based on the discussion,a consensus on the standardization of the testing procedures in NGS laboratories is developed with the aim to standardize NGS testing and accelerate implementation of NGS in clinical settings across China.

Mutations in the synaptic nuclear envelope protein 1 (SYNE1) gene have been reported to cause autosomal recessive cerebellar ataxia (ARCA) type 1 with highly variable clinical phenotypes. The aim of this study was to describe the phenotypic-genetic spectrum of SYNE1-related ARCA1 patients in the Chinese population. We screened 158 unrelated patients with autosomal recessive or sporadic ataxia for variants in SYNE1 using next-generation sequencing. Pathogenicity assessment of SYNE1 variants was interpreted according to the American College of Medical Genetics standards and guidelines. We identified eight truncating variants and two missense variants spreading throughout the SYNE1 gene from six unrelated families, including nine novel variants and one reported variant. Of the six index patients, two patients showed the classical pure cerebellar ataxia, while four patients exhibited non-cerebellar phenotypes, including motor neuron symptoms, cognitive impairment, or mental retardation. The variants associated with motor neuron or cognition involvement tend to be located in the C-terminal region of SYNE1 protein, compared with the variants related to pure cerebellar ataxia. Our data indicating SYNE1 mutation is one of the more common causes of recessive ataxia in the Chinese population. The use of next-generation sequencing has enabled the rapid analysis of recessive ataxia and further expanded our understanding of genotype-phenotype correlation.

Bioinformatic analysis and variant classification are the key components of high-throughput sequencing-based genetic diagnostic approach.This consensus is part of the effort to develop a standardized process for next generation sequencing (NGS)-based test for germline mutations underlying Mendelian disorders in China.The flow-chart,common software,key parameters of bioinformatics pipeline for data processing,annotation,storage and variant classification are reviewed,which is aimed to help improving and maintaining a high-quality process and obtaining consistent outcomes for NGS-based molecular diagnosis.

Objective:To explore the clinical, imaging features and pathogenic mutations in three cases of Gerstmann-Str?ussler-Scheinker syndrome (GSS) with ataxia.Methods:Since 2014, totally 137 probands with autosomal dominant or sporadic ataxia were treated in the Department of Neurology, China-Japan Friendship Hospital. They were screened for mutations in prion protein (PRNP) gene using next-generation sequencing. Spinocerebellar ataxia 1, 2, 3, 6, 7, 8, 12, 17 and dentatorubral-pallidoluysian atrophy were excluded by capillary electrophoresis. Potential pathogenic variants were confirmed by Sanger sequencing. Pathogenicity assessment was interpreted according to the American College of Medical Genetics standards and guidelines. Clinical phenotypes and imaging features of patients were analyzed in detail.Results:Three pedigrees of GSS caused by PRNP gene variants were found. The probands of three pedigrees carried reported heterozygous missense mutation c.305C>T (p.P102L), all onset in adults. All of the three probands showed walking instability and dysarthria, additionally, the proband of pedigree 1 showed parkinsonian signs, the proband of pedigree 2 had cognitive impairment. Brain magnetic resonance imaging showed cerebellar atrophy of different degrees in probands 2 and 3, while pallidum hyperintense signal in proband 1.Conclusions:GSS as a rare subtype of prion disease, could be characterized by cerebellar ataxia. For patients with ataxia, attention should be paid to GSS disease-causing gene mutations in genetic testing. Early diagnosis based on genetic testing will be instrumental in genetic counseling and birth defect intervention in pedigree members.

Objective To investigate the clinical phenotype and genotype manifestations of autosomal recessive hereditary spastic ataxia 2 (SPAX2), to help physicians recognize this disease. Methods and Results A 35-year-old male patient presented with postural tremors, ataxia, hyperreflexia and then got worse progressively. Sanger sequencing found a homozygous missense mutation in the exon 13 c.1089T > G (p.Ile363Met) of KIF1C gene. It came from his parents respectively and was consistent with the autosomal recessive genetic law. The patient was clearly diagnosed as SPAX2, and his family was diagnosed as SPAX2 pedigree. Conclusions KIF1C-related SPAX2 may be considered as a candidate diagnosis for adolescent patients with postural tremor, ataxia and hyperreflexia. DOI: 10.3969/j.issn.1672-6731.2019.06.008

目的 探讨齿状核红核苍白球路易体萎缩症(dentatorubral-pallidoluysian atrophy,DRPLA)患者的临床特征和基因突变特点.方法 选取2005年8月1日至2017年6月30日中日友好医院神经科运动障碍与神经遗传性疾病研究中心收集的1 689例临床拟诊为脊髓小脑共济失调(spinocerebellar ataxias,SCA)的病例,采用聚合酶链反应(polymerase chain reaction,PCR)结合荧光标记毛细管电泳片段分析方法,对患者进行ATN1基因三核苷酸CAG(cytosine-adenineguanine)重复序列检测,并对阳性患者的表型与基因突变相关性进行分析.结果 6例患者携带异常扩增的ATN1基因CAG重复序列,临床表现各异,除以共济失调为主要症状,另伴有癫痫、肌张力障碍、不自主运动及下肢痉挛状态等特殊表型.发病年龄(37.17±11.14)岁,ATN1基因CAG重复序列平均(56.00±2.28)个,Pearson相关分析显示二者呈负相关(r=-4.385,P=0.015).结论 DRPLA在中国人群中罕见;国人DRPLA表型复杂多变,CAG重复次数与发病年龄呈负相关,与病情的严重程度呈正相关.

Objective To investigate the clinical,imaging,intestinal pathological characteristics and prognosis of gluten ataxia (GA).Methods The clinical data,treatment and prognosis in a patient with GA that was confirmed by pathology and hospitalized in the Department of Neurology,China-Japan Friendship Hospital in July 2018,were analyzed retrospectively.The related literature was reviewed and the clinical feature was summarized.Results The patient is a 41-year old man.He suffered from progressive cerebellar ataxia,and the brain magnetic resonance imaging exhibited diffused cerebellar atrophy.Serum human leukocyte antigen (HLA) tests showed that the patient carried HLA-DQ2 genotype.IgA type anti-gliadin antibody was positive (39.39 RU/ml).Duodenoscopy biopsy revealed mild villus atrophy and lymphocytic infiltration,indicating celiac disease.The diagnosis of GA was established then and the patient was administered gluten-free diet combined with intravenous immunoglobulin,which markedly improved the cerebellar symptoms and signs of cerebellar speech,walk capability and daily living activities.He could do long distance driving independently two months later.Conclusions GA is one of immune-mediated reversible acquired cerebellar ataxia caused by gluten sensitivity.The genotype,serologic features,and clinical phenotype of GA in Chinese mainland population might be similar with those in European and American countries.

Objective To summarize phenotype, treatment principles and prognosis of 4 patients from 2 pedigrees with late-onset methylmalonic aciduria (MMA) and homocystinuria cobalamin C (cblC) type, so as to explore the pathophysiological mechanism of this disease. Methods and Results Exome sequencing was applied to rapidly diagnose 2 pedigrees of late-onset MMA and homocystinuria cblC type. The MMACHC gene mutations of the sisters in pedigree 1 were exon 4 c.482G > A (p.Arg161Gln) and c.615C > A (p.Tyr205X). Their parents carried the gene mutation respectively. The proband presented intelligence deterioration, spastic motor dysfunction of lower limbs and epilepsy. The younger sister presented axonal peripheral neuropathy and optic nerve atrophy, while the mental retardation was mild. For the brother and sister in pedigree 2, c.440_441del (p.Gly147fs) and c.482G > A (p.Arg161Gln) in exon 4 of MMACHC gene were identified which came from their parents respectively. The proband presented mental retardation and behavior disorder, weakness of lower limbs with pyramidal sign, and myelinated and axonal mixed peripheral neuropathy. His younger sister had similar symptoms and suffered earlier. After treated by vitamin B12, folic acid and levocarnitine for 6 months, all patients showed intelligence improved and seizures controlled, while still suffered from different degrees of dyskinesia of lower limbs. Conclusions The clinical symptoms of late-onset MMA and homocystinuria cblC type are complex and variable. Cerebral cortex, pyramidal system, extrapyramidal system and peripheral nerve could be widely involved. Target region gene capture combined with next-generation sequencing technology can be used to diagnose the disease rapidly, and early diagnosis and treatment are crucial to improve the prognosis. DOI: 10.3969/j.issn.1672-6731.2019.06.007

Objective To investigate the clinical features of autosomal recessive cerebellar ataxia type 1（ARCA1） and analyze the pathogenic variants in SYNE 1 gene.Methods A cohort of 80 probands of autosomal recessive cerebellar ataxia pedigrees excluding Friedreich ataxia were detected by whole-exome sequencing technology.Poten-

目的:探讨MPZ基因突变致腓骨肌萎缩症(CMT)2I/2J型的临床及神经电生理特点,分析其临床表型与突变的相关性.方法:收集3个MPZ基因突变导致CMT家系的临床表现、家系资料、神经传导检查及基因检测结果,结合文献分析讨论.结果:3个CMT家系分别携带MPZ基因Thr124Met、Asp121Asn和Asn208Tyr杂合突变,主要为中年起病,临床症状为下肢远端无力、萎缩伴感觉异常,其中2例伴听力减退、瞳孔异常、锥体束征等特殊临床表型.3例先证者的神经传导检查均提示主要累及下肢神经的长度依赖性、轴索性运动感觉周围神经病变.结论:MPZ基因Thr124Met、Asp121Asn和Asn208Tyr突变导致CMT 2I/2J型,Thr124Met是热点突变位点.MPZ基因突变相关的CMT患者特殊临床表型出现率较高.

目的:对多系统萎缩(MSA)患者进行生存分析,并研究中医证型是否为该病生存期的预后因素.方法:对82例多系统萎缩患者进行电话随访,统计患者生存期及死亡原因,分析中医证型与生存期的相关性.结果:共完成随访64例,患者平均生存期(8.76±0.74)年,其中死亡患者50例,死亡原因主要为肺部感染及呼吸衰竭27例(54％)、猝死8例(16％)、多脏器衰竭8例(16％)、泌尿系感染4例(8％),不同中医证型间生存期比较无显著差异.结论:多系统萎缩患者最常见的死亡原因为肺部感染及呼吸衰竭,中医证型不是影响多系统萎缩生存期的预后因素.