Kennedy病的临床、电生理和遗传学特点

目的探讨Kennedy病的临床、电生理及遗传学特点。方法对4例Kennedy病患者的临床资料进行回顾性分析。结果 4例患者均为中年男性,缓慢起病。首发症状为双下肢无力2例,咀嚼肌无力2例。主要临床表现为四肢进行性无力,肌肉萎缩,下肢相对较重,进展缓慢;4例患者均有肌束震颤,舌肌萎缩;乳房女性化3例,性功能减退2例。4例均有血清肌酸激酶增高,3例血脂增高、性激素水平升高,1例甲状腺功能异常。EMG表现为广泛的神经源性损害。4例患者的雄激素受体基因第一外显子CAG重复数为45~52。结论 Kennedy病是相对进展缓慢的四肢近端、延髓肌受累,以及内分泌和代谢异常的遗传性神经系统变形疾病,本病的确诊有赖于雄激素受体基因第一外显子CAG重复数的检测。     

Early onset and novel features in a spinal and bulbar muscular atrophy patient with a 68 CAG repeat

Spinal and bulbar muscular atrophy (SBMA) is an X-linked neuromuscular disease caused by a trinucleotide (CAG) repeat expansion in the androgen receptor gene. Patients with SBMA have weakness, atrophy, and fasciculations in the bulbar and extremity muscles. Individuals with CAG repeat lengths greater than 62 have not previously been reported. We evaluated a 29 year old SBMA patient with 68 CAGs who had unusually early onset and findings not seen in others with the disease. Analysis of the androgen receptor gene confirmed the repeat length of 68 CAGs in both peripheral blood and fibroblasts. Evaluation of muscle and sensory function showed deficits typical of SBMA, and in addition the patient had manifestations of autonomic dysfunction and abnormal sexual development. These findings extend the known phenotype associated with SBMA and shed new insight into the effects of the mutated androgen receptor.     

肯尼迪病3个家系的临床、基因型和遗传特征分析

目的分析3个肯尼迪病(Kennedy disease,KD)家系的临床、基因及遗传特征。方法收集3个KD家系患者的详细病史、体格检查、血生化及电生理检查等资料,用基因分析的方法测定先证者及家族成员雄性激素受体(androgen receptor,AR)基因的CAG重复序列拷贝数。结果 3个家系发现的5例KD患者主要临床表现为四肢肌肉萎缩、无力和肢体震颤,舌肌萎缩、纤颤;实验室检查发现肌酸激酶升高;肌电图检查可见失神经电位;神经传导速度检查提示感觉神经受损。KD患者AR基因CAG重复次数在42~49。3个家系的遗传方式符合X连锁隐性遗传。结论 KD主要影响男性患者,病情缓慢进展,主要表现为脊髓和延髓肌肉的萎缩和无力。基因检测有助确诊,并可检测出携带者,以进行家系遗传分析。     

Nonprogressive juvenile-onset spinal muscular atrophy: A clinico-radiological and CAG repeat study of androgen receptor gene

BACKGROUND: Occurrence of nonprogressive juvenile-onset spinal muscular atrophy (SMA) predominantly in males suggests a possibility of X-linked disorder but there is no such report addressing this problem. AIMS: To evaluate CAG repeat expansion of androgen receptor (AR) gene in patients with nonprogressive juvenile-onset SMA. SETTING: Tertiary medical teaching institute. SUBJECTS AND METHODS: Patients fulfilling the diagnostic criteria of nonprogressive juvenile-onset SMA were included. Detailed clinical evaluation and pedigree charting were done in all. Nerve conduction study, electromyography and cervical spinal MRI were carried out. From peripheral venous blood, DNA was separated and AR gene CAG repeat exon polymorphism was assayed using polymerase chain reaction (PCR) in conjugation with genotyping and Gene scan soft ware. Number of CAG repeats was compared with normal controls. RESULTS: 25 patients with nonprogressive juvenile-onset SMA from 24 families were included and their mean age was 22.2 years. Age at the time of disease onset ranged between 15 and 30 years with a mean duration of illness 2.6 years. None of the patients had testicular atrophy or gynecomastia. C7-T1 myotomal wasting and weakness although was unilateral to begin with but became bilateral in 16 and 4 more patients had evidences of subclinical involvement of the other side as revealed by EMG. Spinal MRI revealed cord atrophy at C6-8 vertebral level in 16 patients. CAG repeat study of AR gene was carried out in 16 patients. The number of CAG repeats in patients ranged between 15 and 39 (median 21) which were within the normal range. CONCLUSION: Abnormal CAG repeat expansion of AR gene is not found in patients with nonprogressive juvenile-onset SMA.     

Kennedy病一家系的临床和分子遗传学

目的报道国内首例Kennedy病大家系，探讨其临床特征和分子机制。方法根据先证者的叙述对该家系4代74名个体进行家系调查，进行神经系统体检，常规检测神经电生理、肌电图、血清肌酸磷酸激酶（CPK）等。并经家族成员知情同意后抽取静脉血5ml，标准法抽取基因组DNA，聚合酶链反应（PCR）检测连接素基因（Cx32），证实无基因突变后再检测雄激素受体（AR）基因第一外显子CAG重复片段。结果经临床方法检出家系中另外3例患者，经AR基因检测，其CAG重复数均为50次；而先证者CAG重复数为51次；4例患者肌电图均显示感觉、运动神经受累及，血清CPK均增高；AR基因检测还发现1例症状前个体，其CAG重复数为50次。结论临床上Kennedy病多被误诊为多发性肌炎、肢带型肌营养不良，甚至Charcot-Marie-Tooth病等，AR基因检测是诊断本病最可靠的方法。     

A disorder similar to Huntington's disease is associated with a novel CAG repeat expansion

Huntington's disease (HD) is an autosomal dominant disorder characterized by abnormalities of movement, cognition, and emotion and selective atrophy of the striatum and cerebral cortex. While the etiology of HD is known to be a CAG trinucleotide repeat expansion, the pathways by which this mutation causes HD pathology remain unclear. We now report a large pedigree with an autosomal dominant disorder that is clinically similar to HD and that arises from a different CAG expansion mutation. The disorder is characterized by onset in the fourth decade, involuntary movements and abnormalities of voluntary movement, psychiatric symptoms, weight loss, dementia, and a relentless course with death about 20 years after disease onset. Brain magnetic resonance imaging scans and an autopsy revealed marked striatal atrophy and moderate cortical atrophy, with striatal neurodegeneration in a dorsal to ventral gradient and occasional intranuclear inclusions. All tested affected individuals, and no tested unaffecteds, have a CAG trinucleotide repeat expansion of 50 to 60 triplets, as determined by the repeat expansion detection assay. Tests for the HD expansion, for all other known CAG expansion mutations, and for linkage to chromosomes 20p and 4p were negative, indicating that this mutation is novel. Cloning the causative CAG expansion mutation for this new disease, which we have termed Huntington's disease-like 2, may yield valuable insight into the pathogenesis of HD and related disorders.     

Kennedy病的临床、病理及AR基因分析一例

目的探讨Kennedy病(KD)的临床、病理及基因特点。方法对1例KD患者进行临床、电生理和病理检查。抽取该患者及4位家族成员外周静脉血并抽提其基因组DNA,采用PCR-DNA直接测序的方法进行AR基因分析。结果该患者临床表现为缓慢进行性四肢无力,伴有延髓麻痹、肌肉萎缩、肌束跳动、感觉障碍和男性乳房发育;血脂、肌酶升高;肌电图提示前角细胞损害,周围神经感觉及运动传导速度减慢;肌肉病理可见萎缩的肌纤维及肥大固缩的细胞核;AR基因分析发现患者第一外显子CAG重复突变,重复次数为43次,4位家族成员为19～23次。结论该例为散发性KD患者;KD临床表现不典型,肌电图和病理检查提示神经源性损害,确诊需行AR基因分析。     

A disorder similar to Huntington's disease is associated with a novel CAG repeat expansion.

Huntington's disease (HD) is an autosomal dominant disorder characterized by abnormalities of movement, cognition, and emotion and selective atrophy of the striatum and cerebral cortex. While the etiology of HD is known to be a CAG trinucleotide repeat expansion, the pathways by which this mutation causes HD pathology remain unclear. We now report a large pedigree with an autosomal dominant disorder that is clinically similar to HD and that arises from a different CAG expansion mutation. The disorder is characterized by onset in the fourth decade, involuntary movements and abnormalities of voluntary movement, psychiatric symptoms, weight loss, dementia, and a relentless course with death about 20 years after disease onset. Brain magnetic resonance imaging scans and an autopsy revealed marked striatal atrophy and moderate cortical atrophy, with striatal neurodegeneration in a dorsal to ventral gradient and occasional intranuclear inclusions. All tested affected individuals, and no tested unaffecteds, have a CAG trinucleotide repeat expansion of 50 to 60 triplets, as determined by the repeat expansion detection assay. Tests for the HD expansion, for all other known CAG expansion mutations, and for linkage to chromosomes 20p and 4p were negative, indicating that this mutation is novel. Cloning the causative CAG expansion mutation for this new disease, which we have termed Huntington's disease-like 2, may yield valuable insight into the pathogenesis of HD and related disorders.     

Type IV hyperlipoproteinemia and moderate instability of CAG triplet expansion in the androgen-receptor gene

Kennedy-Alter-Sung (KAS) disease is a hereditary lower motor neuron disease. In this study, we investigated 2 KAS patients presenting with progressive muscle weakness and wasting, action tremor, perioral fasciculation and gynecomastia. Three carriers and 5 healthy members from this 3–generation KAS Chinese family and 60 normal Chinese controls were included in this study. Hormone studies revealed normal serum level in thyrotropin, prolactin, testosterone, leuteinizing hormone, follicle stimulating hormone, and estradiol. Lipid study disclosed type IV hyperlipoproteinemia in 2 KAS patients and 3 healthy members. Molecular studies revealed that the number of CAG triplet repeats in the first exon of androgen receptor gene of the normal allele is in the range of 15–19 and 12–25 in this family and normal controls, respectively. However, the number of CAG repeat of androgen receptor gene were unstable in the mutant alleles with a range of 41–45 and increased from generation to generation (genomic anticipation) in the 2 KAS patients and 3 female carriers. We conclude that the CAG triplet repeats in mutant alleles were unstable in the family with the KAS disease. Furthermore, type IV hyperlipoproteinemia may be a co-transmitted syndrome in the family with KAS disease.     

Clinical spectrum of AIFM1‐associated disease in an Irish family,from mild neuropathy to severe cerebellar ataxia with colour blindness

Mutations in apoptosis‐inducing factor mitochondrion‐associated‐1 (AIFM1) cause X‐linked peripheral neuropathy (Cowchock syndrome, CMT4X); however, more recently a cerebellar presentation has been described. We describe a large Irish family with seven affected males. They presented with a variable age of onset, 18 months to 39 years of age. All developed variably present sensorineural deafness, peripheral neuropathy, cerebellar ataxia, and pyramidal involvement. In addition, three had colour vision deficiency. Scale for the assessment and rating of ataxia ranged 2 to 23/40, while Charcot‐Marie‐Tooth neuropathy score 2 varied between 7 and 13/36. All individuals had normal cognitive assessment. Neurophysiology demonstrated length‐dependent large‐fibre sensorimotor axonal neuropathy, with particular involvement of superficial radial sensory responses. Brain imaging, performed in four, revealed varying extent of cerebellar atrophy, and white matter changes in one. Optical coherence tomography was abnormal in one, who had unrelated eye pathology. Four obligate female carriers were assessed clinically, two of them neurophysiologically; all were unaffected. Whole genome sequencing demonstrated a previously reported hemizygous AIFM1 mutation. Analysis for mutations in other genes associated with colour deficiency was negative. AIFM1‐associated phenotype in this family demonstrated significant variability. To our knowledge, this is the first report of AIFM1‐associated colour blindness. Superficial radial nerve was particularly affected neurophysiologically, which could represent a phenotypic marker towards this specific genetic diagnosis.     

A novel X‐linked four‐repeat tauopathy with Parkinsonism and spasticity

The parkinsonian syndromes comprise a highly heterogeneous group of disorders. Although 15 loci are linked to predominantly familial Parkinson's disease (PD), additional PD loci are likely to exist. We recently identified a multigenerational family of Danish and German descent in which five males in three generations presented with a unique syndrome characterized by parkinsonian features and variably penetrant spasticity for which X‐linked disease transmission was strongly suggested (XPDS). Autopsy in one individual failed to reveal synucleinopathy; however, there was a significant four‐repeat tauopathy in the striatum. Our objective was to identify the locus responsible for this unique parkinsonian disorder. Members of the XPDS family were genotyped for markers spanning the X chromosome. Two‐point and multipoint linkage analyses were performed and the candidate region refined by analyzing additional markers. A multipoint LOD_max score of 2.068 was obtained between markers DXS991 and DXS993. Haplotype examination revealed an ～20 cM region bounded by markers DXS8042 and DXS1216 that segregated with disease in all affected males and obligate carrier females and was not carried by unaffected at‐risk males. To reduce the possibility of a false‐positive linkage result, multiple loci and genes associated with other parkinsonian or spasticity syndromes were excluded. In conclusion, we have identified a unique X‐linked parkinsonian syndrome with variable spasticity and four‐repeat tau pathology, and defined a novel candidate gene locus spanning ～28 Mb from Xp11.2–Xq13.3. © 2010 Movement Disorder Society     

Patient‐identified impact of symptoms in spinal and bulbar muscular atrophy

Introduction: The effects of spinal bulbar muscular atrophy (SBMA) on quality of life (QoL) are not well understood. This study describes symptoms from the patient's perspective and the impact these symptoms have on QoL. Methods: We conducted open‐ended interviews with 21 adult men with genetically confirmed SBMA. Using a qualitative framework technique, we coded and analyzed interviews to identify symptoms and resulting themes. Results: From these interviews, 729 quotations were extracted. We identified 200 SBMA‐specific symptoms and 20 symptomatic themes. Weakness was mentioned by all interviewees. Symptoms within the domain of mental health and the specific themes of emotional issues and psychological impact were also frequently mentioned. Discussion: Numerous symptoms affect QoL for patients with SBMA. We identified previously unrecognized symptoms that are important to address in enhancing clinical care for patients with SBMA and in developing tools to evaluate efficacy in future clinical trials. Muscle Nerve 57 : 40–44, 2018     

A family with adult spinal and bulbar muscular atrophy, X-linked inheritance and associated testicular failure

A family with adult spinal and bulbar muscular atrophy with X-linked recessive inheritance (Kennedy's disease) is described. Affected members presented at age 20 with muscle cramps followed insidiously by gynaecomastia, partial loss of secondary sexual traits, loss of libido and inability to maintain an erection. Three had also testicular atrophy and severe oligospermia was found in two patients. Testicular biopsy in one case showed germinal failure with almost normal Leydig cells. Hormonal tests were suggestive of a primary testicular failure. Etiologic possibilities are considered.     

MJD1基因单个碱基多态性与CAG重复序列不稳定性的关系

马查多－约瑟夫病患者的ＭＪＤ１基因存在ＣＡＧ三核苷酸不稳定扩展突变，为探讨这种不稳定扩展突变的分子机制。方法对５８名正常人和２０名ＭＪＤ患者的ＭＪＤ１基因内ＣＡＧ／ＣＡＡ、ＣＧＧ／ＧＧＧ两个位点的多态性进行检测。结果正常染色体中，具有ＣＧＧ等位基因的ＣＡＧ重复数目（２７．３２±０．６１，ｎ＝２８）较具有ＧＧＧ等位基因的ＣＡＧ重复数目（１５．９０±０．６９，ｎ＝３０）明显大（Ｐ＜０．０１）。ＣＧＧ等位基因在患者中的分布频率（１００％）明显高于正常人（４８．３％）。结论ＭＪＤ１基因内单个碱基置换影响ＣＡＧ重复序列的稳定性。     

Case of maternally transmitted juvenile Huntington's disease with a very large trinucleotide repeat.

We describe and present a video of a patient with maternally inherited juvenile Huntington's disease (HD) caused by a very large (108-repeat) expansion. Maternally transmitted very large trinucleotide repeats (>100) are extremely rare in juvenile HD and may represent instability during female gametogenesis.     

Novel Lamp-2 gene mutation and successful treatment with heart transplantation in a large family with Danon disease

Lysosome-associated membrane protein-2 deficiency (LAMP-2 deficiency), or Danon disease, is a rare X-linked lysosomal disease characterized by cardiomyopathy, vacuolar myopathy, and mental retardation. Less than 20 families with mutations of the Lamp-2 gene have been reported. We describe a family from Sardinia with eight affected patients (4 females and 4 males) and a novel mutation in exon 2 of the Lamp-2 gene (c.102_103delAG). Females developed isolated cardiomyopathy in adulthood, whereas males presented with cardiomyopathy, myopathy, and mental retardation before the age of 20 years. Cardiomyopathy was lethal in three females in their 40s and in three males before the age 20 years. One patient was successfully treated by heart transplantation with more than 5-year follow-up. This study demonstrates that Danon disease is a frequently fatal condition that is potentially treatable with heart transplantation.     

A series of West European patients with severe cardiac and skeletal myopathy associated with a de novo R406W mutation in desmin

Abstract. Desminopathy is a familial or sporadic cardiac and skeletal muscular dystrophy associated with mutations in desmin. We have previously characterized a de novo desmin R406W mutation in a patient of European origin with early onset muscle weakness in the lower extremities and atrioventricular conduction block requiring a permanent pacemaker. The disease relentlessly progressed resulting in severe incapacity within 5 years after onset. We have now identified three other patients with early onset rapidly progressive cardiac and skeletal myopathy caused by this same desmin R406W mutation. The mutation was present in each studied patient, but not in their parents or other unaffected family members, indicating that the mutation in all four cases was generated de novo. The patients mutationcarrying chromosomes showed no similarity, suggesting that the R406W mutation has occurred independently. These observations strongly confirm that the de novo R406W desmin mutation is the genetic basis for early-onset cardiac and skeletal myopathy in patients with sporadic disease and indicate that desmin position 406 is a hot spot for spontaneous mutations. The high pathogenic potential of this mutation can be explained by its location in the highly conserved YRKLLEGEE motif at the C-terminal end of the 2B helix that has a critical role in the process of desmin filament assembly.     

A mutation in the heptad repeat 2 domain of MFN2 in a large CMT2A family

Dominant mutations in MFN2 cause a range of phenotypes, including severe, early‐onset axonal neuropathy, “classical CMT2,” and late‐onset axonal neuropathies. We report a large family with an axonal polyneuropathy, with clinical onset in the 20s, followed by slow progression.     

A case of severe autosomal dominant spinal muscular atrophy with lower extremity predominance caused by a de novo BICD2 mutation

BackgroundHeterozygous variants in BICD2 cause autosomal dominant spinal muscular atrophy with lower extremity predominance. These variants are also identified in individuals with severe forms of congenital muscle atrophy representing arthrogryposis multiplex.Case reportA girl was born with severe muscle weakness and respiratory distress. A fetal ultrasound had detected polyhydramnios and multiple joint contractures in utero. She was born with severe muscle weakness and respiratory distress. Bilateral hip joint dislocation and multiple bone fractures were also present at birth. Although she depends on medical care, including assisted ventilation and tube feeding, she has reached eight years of age. Her motor developmental skills were reduced owing to muscle weakness and deformity of her lower extremities, whereas her cognitive development slowly but steadily grew. Whole exome sequencing revealed a novel de novo missense BICD2 variant (c.1625G > A, p.(Cys542Tyr)), which was evaluated as likely pathogenic.ConclusionThis is the first case report of a severe form of spinal muscular atrophy with lower extremity predominance caused by a de novo BICD2 variant in Japan.