BACKGROUND Spinocerebellar ataxia recessive type 7(SCAR7)is a rare clinical manifestation beginning in childhood or adolescence.SCAR7 is caused by tripeptidyl peptidase 1(TPP1)gene mutations,and presents with cerebell...BACKGROUND Spinocerebellar ataxia recessive type 7(SCAR7)is a rare clinical manifestation beginning in childhood or adolescence.SCAR7 is caused by tripeptidyl peptidase 1(TPP1)gene mutations,and presents with cerebellar ataxia,pyramidal signs,neurocognitive impairment,deep paresthesia,and cerebellar atrophy.CASE SUMMARY Here,we describe a 25-year-old female patient in China who presented with increasing difficulty walking,falling easily,shaking limbs,instability holding items,slurred speech,coughing when drinking,palpitations,and frequent hunger and overeating.Magnetic resonance imaging showed cerebellar atrophy.Whole exome sequencing detected two compound heterozygous mutations in the TPP1 gene:c.1468G>A p.Glu490Lys and c.1417G>A p.Gly473Arg.Considering the patient’s clinical presentation and genetic test results,we hypothesized that complex heterozygous mutations cause TPP1 enzyme deficiency,which may lead to SCAR7.CONCLUSION We report the first case of SCAR7 from China.We also identify novel compound heterozygous mutations in the TPP1 gene associated with SCAR7,expanding the range of known disease-causing mutations for SCAR7.展开更多
Spinocerebellar ataxias （SCAs） are a group of genetic disorders characterized by slowly progressive incoordina- tion of gait and are often associated with poor coordination of the hands, speech, and eye movements. F...Spinocerebellar ataxias （SCAs） are a group of genetic disorders characterized by slowly progressive incoordina- tion of gait and are often associated with poor coordination of the hands, speech, and eye movements. Frequently, atrophy of the cerebellum occurs. The genetic forms of ataxia are diagnosed by family history, physical examina- tion, neuroimaging, and molecular genetic testing. At present, 36 SCA subtypes including 27 pathogenic genes have been identified [1]. Different subtypes of SCAs have clear distribution differences among ethnic populations, and SCA8 is an infrequent entity worldwide, which has mostly been reported in Japanese, but has never been reported in Chinese [2]. SCAB involves bidirectional expression based on the total number of both the （CTA）n and （CTG）n expansion transcripts in ATXN8OS. The pathogenesis of this disorder is complex and the spectrum of clinical presentations is broad. It is predominantly characterized by drawn-out slowness of speech and gait instability, followed by slowly progressive ataxia, with disease onset typically occurring in adulthood [3]. How- ever, the lowest full-penetrance allele for SCA8 onset remains elusive and the current understanding of the phenotypic and genotypic features of SCA8 is limited. Since SCA8 has not yet been reported in the Chinese population and is scantily reported in a small proportion of pedigrees so far, clinical knowledge is still developing. Moreover, the boundary between the normal and patho- genic alleles of SCA8 is uncertain. Here we report the clinical and molecular genetic characteristics of 3 Chinese SCA8 families and have identified 51 CTA/CTG repeats within ATXN8OS, probably the shortest pathogenic allele for SCA8.展开更多
Background Spinocerebellar ataxia type 7 （SCA7） is known as an autosomal dominant cerebellar ataxia; patients with genetically confirmed diagnoses of SCA7 have increased rapidly in recent years.However, SCA7 is a ra...Background Spinocerebellar ataxia type 7 （SCA7） is known as an autosomal dominant cerebellar ataxia; patients with genetically confirmed diagnoses of SCA7 have increased rapidly in recent years.However, SCA7 is a rare subtype of SCA, and most data available about SCA7 are those of white people.The aim of the present study was to systematically review the prevalence and clinical and genetic aspects of SCA7 patients in East Asian population.Methods A search for publications on SCA7 was performed by using the ＂PubMed＂ database with the published language limited in English.Publications mainly focusing on the prevalence of SCA7 in patients with SCA and the clinical and genetic features of SCA7 patients were fully reviewed and analyzed.Results The prevalence of SCA7 in SCA patients ranged from 0 to 7.7%, which was similar to those reported previously.The clinical manifestations were typically present at the 30＇s of its victims （median, 29 years; interquartile range （IQR）,19.5-36.5 years）, and the symptoms appeared 15 years （（15.17±4.22） years） earlier on average in the offspring than in the parents.Gait ataxia and visual impairment were both found in all patients of whom the clinical features were described.Mutant SCA7 alleles contained 40-100 CAG repeats, with a median of 47 repeats （IQR, 44.5-50.0）; and the offspring had 13 more repeats on average compared with their parents （12.62±19.03）.A strong negative correlation was found between CAG repeat size and the onset age of patients （r=-0.739, P=0.000）.In addition, no significant difference was found in CAG repeat sizes between patients with visual impairment as the initial symptom and those with gait disturbance as their initial symptom （P=0.476）.Conclusions The prevalence of SCA7 in SCA patients, the age at onset and CAG repeats of SCA7 patients in East Asia are consistent with those of white people.However, larger population study is needed to assess the correlation between the CAG repeat size and initial symptoms of SCA7 patients in East Asia.展开更多
基金Supported by Postdoctoral program of the Affiliated Hospital of Jining Medical University,No.JYFY303573Health Commission of Shandong Province,No.202006010928+1 种基金Academician Lin He New Medicine in Jining Medical University,No.JYHL2018FMS05Affiliated Hospital of Jining Medical University,No.2018-BS-004.
文摘BACKGROUND Spinocerebellar ataxia recessive type 7(SCAR7)is a rare clinical manifestation beginning in childhood or adolescence.SCAR7 is caused by tripeptidyl peptidase 1(TPP1)gene mutations,and presents with cerebellar ataxia,pyramidal signs,neurocognitive impairment,deep paresthesia,and cerebellar atrophy.CASE SUMMARY Here,we describe a 25-year-old female patient in China who presented with increasing difficulty walking,falling easily,shaking limbs,instability holding items,slurred speech,coughing when drinking,palpitations,and frequent hunger and overeating.Magnetic resonance imaging showed cerebellar atrophy.Whole exome sequencing detected two compound heterozygous mutations in the TPP1 gene:c.1468G>A p.Glu490Lys and c.1417G>A p.Gly473Arg.Considering the patient’s clinical presentation and genetic test results,we hypothesized that complex heterozygous mutations cause TPP1 enzyme deficiency,which may lead to SCAR7.CONCLUSION We report the first case of SCAR7 from China.We also identify novel compound heterozygous mutations in the TPP1 gene associated with SCAR7,expanding the range of known disease-causing mutations for SCAR7.
基金supported by grants from the National Natural Science Foundation of China(81301486 and81672095)
文摘Spinocerebellar ataxias （SCAs） are a group of genetic disorders characterized by slowly progressive incoordina- tion of gait and are often associated with poor coordination of the hands, speech, and eye movements. Frequently, atrophy of the cerebellum occurs. The genetic forms of ataxia are diagnosed by family history, physical examina- tion, neuroimaging, and molecular genetic testing. At present, 36 SCA subtypes including 27 pathogenic genes have been identified [1]. Different subtypes of SCAs have clear distribution differences among ethnic populations, and SCA8 is an infrequent entity worldwide, which has mostly been reported in Japanese, but has never been reported in Chinese [2]. SCAB involves bidirectional expression based on the total number of both the （CTA）n and （CTG）n expansion transcripts in ATXN8OS. The pathogenesis of this disorder is complex and the spectrum of clinical presentations is broad. It is predominantly characterized by drawn-out slowness of speech and gait instability, followed by slowly progressive ataxia, with disease onset typically occurring in adulthood [3]. How- ever, the lowest full-penetrance allele for SCA8 onset remains elusive and the current understanding of the phenotypic and genotypic features of SCA8 is limited. Since SCA8 has not yet been reported in the Chinese population and is scantily reported in a small proportion of pedigrees so far, clinical knowledge is still developing. Moreover, the boundary between the normal and patho- genic alleles of SCA8 is uncertain. Here we report the clinical and molecular genetic characteristics of 3 Chinese SCA8 families and have identified 51 CTA/CTG repeats within ATXN8OS, probably the shortest pathogenic allele for SCA8.
文摘Background Spinocerebellar ataxia type 7 （SCA7） is known as an autosomal dominant cerebellar ataxia; patients with genetically confirmed diagnoses of SCA7 have increased rapidly in recent years.However, SCA7 is a rare subtype of SCA, and most data available about SCA7 are those of white people.The aim of the present study was to systematically review the prevalence and clinical and genetic aspects of SCA7 patients in East Asian population.Methods A search for publications on SCA7 was performed by using the ＂PubMed＂ database with the published language limited in English.Publications mainly focusing on the prevalence of SCA7 in patients with SCA and the clinical and genetic features of SCA7 patients were fully reviewed and analyzed.Results The prevalence of SCA7 in SCA patients ranged from 0 to 7.7%, which was similar to those reported previously.The clinical manifestations were typically present at the 30＇s of its victims （median, 29 years; interquartile range （IQR）,19.5-36.5 years）, and the symptoms appeared 15 years （（15.17±4.22） years） earlier on average in the offspring than in the parents.Gait ataxia and visual impairment were both found in all patients of whom the clinical features were described.Mutant SCA7 alleles contained 40-100 CAG repeats, with a median of 47 repeats （IQR, 44.5-50.0）; and the offspring had 13 more repeats on average compared with their parents （12.62±19.03）.A strong negative correlation was found between CAG repeat size and the onset age of patients （r=-0.739, P=0.000）.In addition, no significant difference was found in CAG repeat sizes between patients with visual impairment as the initial symptom and those with gait disturbance as their initial symptom （P=0.476）.Conclusions The prevalence of SCA7 in SCA patients, the age at onset and CAG repeats of SCA7 patients in East Asia are consistent with those of white people.However, larger population study is needed to assess the correlation between the CAG repeat size and initial symptoms of SCA7 patients in East Asia.
