Clinical and genetic analysis of a patient with Desminopathy manifesting initially with myalgia after lower limb activity / 中华医学遗传学杂志

OBJECTIVE@#To explore the clinical characteristics and genetic variant of a patient with desminopathy manifesting with atypical symptoms.@*METHODS@#A patient who was admitted to the Department of Neurology of Jing'an District Central Hospital on February 24, 2021 was selected as the study subject. Clinical data, laboratory tests, muscle pathology, muscle magnetic resonance imaging (MRI) and genetic testing of the patient were retrospectively analyzed.@*RESULTS@#The patient had developed myalgia after lower limb activity, and gradually developed asymmetrical muscle weakness and atrophy of the lower limbs. Cardiac examination revealed atrioventricular block and decreased left ventricular diastolic function. Muscle MRI showed that semitendinosus, sartorius, gracilis, fibula, gastronemius and supinator muscles were selectively involved at the early stage. Muscle biopsy confirmed pathological changes of desmin positive myofibrils. Genetic testing revealed that the patient has harbored a c.1024A>G (p.n342d) missense variant in exon 6 of the DES gene. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the variant was rated as likely pathogenic (PS4_moderate+PM2_supporting+PP3_moderate+PP1).@*CONCLUSION@#Desmin disease has a great clinical heterogeneity. Postexercise myalgia of lower limbs is a rare clinical phenotype. For patients harboring the c.1024A>G (p.n342d) variant of the DES gene, in addition to semitendinosus and fibula, Cardiac involvement is relatively insidious and easy to be ignored in clinic. Timely muscle MRI, muscle biopsy and gene detection will help the early diagnosis of the disease.

Role of sphingolipids signaling in pathogenesis of pulmonary fibrosis / 中国药理学与毒理学杂志

Pulmonary fibrosis is a group of chronic lung diseases caused by various factors and characterized by chronic inflammations,lung tissue structure damage,increase of pulmonary interstitial collagen and massive deposition of extracellular matrix (ECM). Because of its complicated etiology, there is no effective treatment currently. Recent studies showed that the activation of sphingolipids signaling and pulmonary fibrosis were closely related. This paper describes the composition and function of sphingolipids signaling pathway and its effect on fibrosis in order to provide new ideas about further study of the pathogenesis of pulmonary fibrosis and methods of prevention.

Studies on the CAG repeat expansion in patients with hereditary spinocerebellar ataxia from Chinese Han / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate the CAG trinucleotide repeat expansion in spinocerebellar ataxia (SCA) types 1, 2, 3, 6, 7, 12, and 17 from Chinese Han.</p><p><b>METHODS</b>The pathological CAG triplet repeat expansions of the SCA1, SCA2, SCA3/Machado-Joseph disease (MJD), SCA6, SCA7, SCA12 and SCA17 genes were analyzed in a cohort of 559 Mainland Chinese patients affected by spinocerebellar ataxia, including 363 probands from families with autosomal dominant SCA and 196 sporadic cases. Polymerase chain reaction, agarose gel electrophoresis, recombinant DNA technology by T-vector cloning and direct sequencing were performed to detect the CAG-repeat number of abnormal allele.</p><p><b>RESULTS</b>Among the 559 SCA patients, twenty-three were positive for SCA1, the ranges of expanded CAG repeats were from 39 to 60 (mean:51.09+/-4.88); thirty-two were positive for SCA2, the ranges of expanded CAG repeats were from 36 to 51 (mean:40.34+/-4.40); three hundred and five were positive for SCA3/MJD, the ranges of expanded CAG repeats were from 49 to 86 (mean:73.84+/-5.07); nine were positive for SCA6, the ranges of expanded CAG repeats were from 23 to 29 (mean:25.56+/-1.94); twenty-seven were positive for SCA7, the ranges of expanded CAG repeats were from 38 to 71(mean:58.22+/-10.90); three were positive for SCA12, the ranges of expanded CAG repeats were from 51 to 52 (mean:51.33+/-0.58); and finally, two were positive for SCA17, the range of expanded CAG repeats were from 53 to 55 (mean:54.00+/-1.41).</p><p><b>CONCLUSION</b>The 39 CAG repeats of SCA1, 49 CAG repeats of SCA3 and 51 CAG repeats of SCA12 are all the shortest known causative expanded alleles, while the 86 CAG repeats of SCA3/MJD is the largest full expanded allele that has never been reported. Furthermore, it is the first report of SCA17 subtype in Mainland Chinese and first research that established the abnormal reference standard of CAG repeat number of different subtypes of SCA in Chinese Han.</p>

Frequency of spinocerebellar ataxia types 1, 2, 3, 6, 7, 8, 10, 12, 17 and dentatorubral-pallidoluysian atrophy in Chinese Han population / 中华神经科杂志

Objective To assess the frequency of different subtype of spinocerebellar ataxias (SCAs) in Chinese Han population. Methods The nueleotide repeat mutations of SCA1, SCA2, SCA3/ MJD, SCA6, SCAT, SCA8, SCA10, SCA12, SCA17 and dentatorubral-pallidoluysian atrophy (DRPLA) were detected by the polymerase chain reaction (PCR), denaturing polyacrylamide gel electrophoresis (PAGE), Southern blot, recombinant DNA technology by T-vector cloning and direct sequencing technique in a cohort of 559 Mainland Chinese patients affected by spinocerebellar ataxia, including 363 families with autosomal dominant SCA (AD-SCA) and 196 sporadic cases. Results Among the 363 AD-SCA families, 15 families (4. 13%) were positive for SCA1, 26 (7. 16%) for SCA2, 187 (51.52%) for SCA3/MJD, 6 (1.65%) for SCA6, 7 (1.93%) for SCA7, 1 (0. 28%) for SCA12 and 1 (0. 28%) positive for SCA17; 120(33. 06%) were negative for all the tested SCAs. There were 2 (1.02%) SCAI, 3 (1.53%) SCA2, 15 (7. 65%) SCA3/MJD, 3 (1.53%) SCA6 and 173 (88.27%) not identified in the 196 sporadic SCA patients. None of the SCA8, SCA10 and DRPLA mutation was found. Conclusions SCA3/MJD is a substantially common subtype of AD-SCAs and sporadic SCA in Chinese Han patients with SCAs, subsequently followed by SCA2, SCA1, SCAT and SCA6; SCA12 and SCA17 are uncommon subtypes, while SCA8, SCA10, and DRPLA are rare, if not absent. SCA17 subtype was initially identified in mailand China. Some other genes might be causative in those unidentified AD-SCA pedigrees, and other etiological factors besides genetic cause might contribute for those sporadic cases.

Study on the single-nucleotide substitution (c.-16C to T) of the PURATROPHIN-1 gene in Chinese patients with spinocerebellar ataxia / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To study the single-nucleotide substitution (c.-16C to T) of the PURATROPHIN-1 gene in spinocerebellar ataxia (SCA) patients in China.</p><p><b>METHODS</b>The single-nucleotide substitution (c.-16C to T) of the PURATROPHIN-1 gene was detected by PCR, digested with EcoN I, separated on 8% polyacrylamide gel in 68 probands of autosomal dominant SCA families and 119 sporadic SCA patients, who had been excluded CAG/CAA repeat expansion at the SCA1, 2, 3, 6, 7, 17 and dentatorubral-pallidolluysian atrophy (DRPLA) loci. The results were confirmed in four patients by direct sequencing.</p><p><b>RESULTS</b>The single-nucleotide substitution (c.-16C to T) of the PURATROPHIN-1 gene was not identified in authors' cohort.</p><p><b>CONCLUSION</b>The mutation of c.-16C to T of the PURATROPHIN-1 gene might be rare in SCA patients in China.</p>