Dual Mechanism of a New SMN1 Variant (c.835G>C, p.Gly279Arg) by Interrupting Exon 7 Skipping and YG Oligomerization in Causation of Spinal Muscular Atrophy.

Spinal muscular atrophy (SMA) is an autosomal recessive neuromuscular disorder caused by deletion or subtle variant of survival motor neuron 1 (SMN1) gene. By multiplex ligation-dependent probe amplification, genomic sequencing, and T-A cloning on cDNA level, we identified one novel SMN1 subtle variant c.835G>C (p.

Diagnosis of Spinal Muscular Atrophy: A Simple Method for Quantifying the Relative Amount of Survival Motor Neuron Gene 1/2 Using Sanger DNA Sequencing.

Background: Spinal muscular atrophy (SMA) is caused by homozygous deletion or compound heterozygous mutation of survival motor neuron gene 1 (SMN1), which is the key to diagnose SMA. The study was to establish and evaluate a new diagnostic method for SMA.

Methods: A total of 1494 children suspected with SMA were enrolled in this study.

The SMN1 common variant c.22 dupA in Chinese patients causes spinal muscular atrophy by nonsense-mediated mRNA decay in humans.

Spinal muscular atrophy (SMA) is a common autosomal recessive neuromuscular disorder that is mostly caused by homozygous deletion of the SMN1 gene. Approximately 5%-10% of SMA patients are believed to have SMN1 variants. c.

p.Val19Glyfs*21 and p.Leu228* variants in the survival of motor neuron 1 trigger nonsense-mediated mRNA decay causing the SMN1 PTC+ transcripts degradation.

Spinal Muscular Atrophy (SMA) results from loss-of-function mutations in the survival of motor neuron 1 (SMN1) gene. Our previous research showed that 40% of variants were nonsense or frameshift variants and SMN1 mRNA levels in the patients carrying these variants were significantly decreased. Here we selected one rare variant (p.

Mutation Spectrum of the Survival of Motor Neuron 1 and Functional Analysis of Variants in Chinese Spinal Muscular Atrophy.

Proximal spinal muscular atrophy (SMA) is a common fatal autosomal recessive disorder caused by deletion or mutation of the survival of motor neuron 1 (SMN1). Here, we studied SMA molecular pathology in 653 Chinese patients and found approximately 88.2% with homozygous SMN1 exon 7 deletion and 6.

A novel large deletion mutation of FERMT1 gene in a Chinese patient with Kindler syndrome.

Kindler syndrome (KS; OMIM 173650) is a rare autosomal recessive skin disorder, which results in symptoms including blistering, epidermal atrophy, increased risk of cancer, and poor wound healing. The majority of mutations of the disease-determining gene (FERMT1 gene) are single nucleotide substitutions, including missense mutations, nonsense mutations, etc. Large deletion mutations are seldom reported.

A rare variant (c.863G>T) in exon 7 of SMN1 disrupts mRNA splicing and is responsible for spinal muscular atrophy.

Proximal spinal muscular atrophy (SMA) is an autosomal recessive neuromuscular disorder caused by deletion or mutation of SMN1 (survival motor neuron 1). SMN exon 7 splicing is regulated by a number of exonic and intronic regulatory sequences and the trans-factors that bind them. Variants located in or near these regulated regions should be evaluated to determine their effect on splicing.

Fast clinical molecular diagnosis of hyperphenylalaninemia using next-generation sequencing-based on a custom AmpliSeq™ panel and Ion Torrent PGM sequencing.

Hyperphenylalaninemia (HPA) can be classified into phenylketonuria (PKU) and tetrahydrobiopterin deficiency (BH4D), according to the defect of enzyme activity, both of which vary substantially in severity, treatment, and prognosis of the disease. To set up a fast and comprehensive assay in order to achieve early etiological diagnosis and differential diagnosis for children with HPA, we designed a custom AmpliSeq™ panel for the sequencing of coding DNA sequence (CDS), flanking introns, 5' untranslated region (UTR) and 3' UTR from five HPA-causing genes (PAH, PTS, QDPR, GCH1, and PCBD1) using the Ion Torrent Personal Genome Machine (PGM) Sequencer. A standard group of 15 samples with previously known DNA sequences and a test group of 37 HPA patients with unknown mutations were used for assay validation and application, respectively.

Association of copy numbers of survival motor neuron gene 2 and neuronal apoptosis inhibitory protein gene with the natural history in a Chinese spinal muscular atrophy cohort.

We evaluated survival motor neuron 2 (SMN2) and neuronal apoptosis inhibitory protein (NAIP) gene copy distribution and the association of copy number with survival in 232 Chinese spinal muscular atrophy (SMA) patients. The SMN2 and NAIP copy numbers correlated positively with the median onset age (r = 0.72 and 0.

Subtle mutation detection of SMN1 gene in Chinese spinal muscular atrophy patients: implication of molecular diagnostic procedure for SMN1 gene mutations.

Spinal muscular atrophy (SMA) is a common autosomal recessive neuromuscular disorder caused by mutations of the survival of motor neuron 1 (SMN1) gene. Approximately 90-95% of SMA patients have a homozygous deletion of SMN1, and 5-10% of patients are believed to have subtle mutations. The molecular diagnosis of SMN1 subtle mutations is hampered by a highly homologous SMN2 gene.

Two unrelated patients with rare Crigler-Najjar syndrome type I: two novel mutations and a patient with loss of heterozygosity of UGT1A1 gene.

Crigler-Najjar syndrome type I (CN-I) is the most severe type of hereditary unconjugated hyperbilirubinemia. It is caused by homozygous or compound heterozygous mutations of the UDP-glycuronosyltransferase gene (UGT1A1) on chromosome 2q37. Two patients clinically diagnosed with CN-I were examined in this paper.

[Detection of homozygous deletions in spinal muscular atrophy with genomic DNA sequencing].

Objective: To detect homozygous deletions of survival motor neuron (SMN) gene with genomic DNA sequencing, and to assess the value of genetic testing for the diagnosis of spinal muscular atrophy (SMA).

Methods: Polymerase chain reaction (PCR) was used for amplifying SMN gene in 100 SMA patients and 110 controls. Four different bases (g.

Subtle mutations in the SMN1 gene in Chinese patients with SMA: p.Arg288Met mutation causing SMN1 transcript exclusion of exon7.

Background: Proximal spinal muscular atrophy (SMA) is a common neuromuscular disorder resulting in death during childhood. Around 81~95% of SMA cases are a result of homozygous deletions of survival motor neuron gene 1 (SMN1) gene or gene conversions from SMN1 to SMN2. Less than 5% of cases showed rare subtle mutations in SMN1.

Compound mutations (R237X and L375P) in the fumarylacetoacetate hydrolase gene causing tyrosinemia type I in a Chinese patient.

Background: Mutations in fumarylacetoacetate hydrolase (FAH) gene can lead to tyrosinemia type 1 (HT1), a relatively rare autosomal recessive disorder. To date, no molecular genetic defects of HT1 in China have been described. We investigated a Chinese family with a HT1 child to identify mutations in FAH.

[Limitation of PCR-RFLP method for the detection of genetic mutations in spinal muscular atrophy].

Objective: To explore the applicability and limitation of PCR-restriction fragment length polymorphism (PCR-RFLP) method for genetic diagnosis of spinal muscular atrophy (SMA).

Methods: PCR-RFLP was applied to detect potential deletion in exons 7 and 8 of SMN1 gene in 935 suspected cases with SMA. Multiplex ligation-dependent probe amplification(MLPA) was carried out to analyze dosage alteration of SMN1 gene in 339 of such cases.

[Analysis of survival motor neuron gene conversion in patients with spinal muscular atrophy].

Objective: To investigate the type and frequency of gene conversion from SMN1 to SMN2 in Chinese patients affected with spinal muscular atrophy (SMA), and to explore the relationship between gene conversion and clinical phenotype.

Methods: Non-homozygous deletion of SMN1 gene exon 8 was screened among 417 patients with SMN1 exon 7 homozygous deletions. To analyze and verify the types of gene conversion, genomic DNA sequencing, multiplex ligation-dependent probe amplification (MLPA), and gene subcloning and sequencing were carried out.

[Mutation analysis of SMN1 gene in patients with spinal muscular atrophy].

Objective: Spinal muscular atrophy (SMA) is an autosomal recessive neuromuscular disorder. About 80% - 90% of SMA patients are missing both copies of SMN1, and 5% - 10% of patients are compound heterozygotes. In the present study, we aimed to analyze survival motor neuron 1 (SMN1) gene mutation in three patients with spinal muscular atrophy and their families to explore the effect of mutation on SMN protein function and the relationship between mutation and clinical phenotype.

[Point mutation analysis of SMN1 gene in patients with spinal muscular atrophy].

Objective: To identify the point mutations in survival motor neuron gene 1 SMN1 gene and confirm the existence of compound heterozygous mutations in Chinese patients with spinal muscular atrophy (SMA).

Methods: Three unrelated patients were diagnosed and clinically typed according to the criteria of proximal SMA established by the International SMA Consortium. Multiplex ligation-dependent probe amplification (MLPA) analysis was carried out to measure the copy numbers of SMN1, SMN2 and neuronal apoptosis inhibitory protein gene (NAIP)in the patients.

Compound heterozygous mutation in two unrelated cases of Chinese spinal muscular atrophy patients.

Background: Infantile proximal spinal muscular atrophy (SMA) is a common autosomal recessive neuromuscular disorder. Approximately 90% - 95% cases of SMA result from homozygous deletion of survival motor neuron gene 1 (SMN1) and 5% cases are caused by compound heterozygous mutation (a SMN1 deletion on one allele and a subtle mutation on the other allele).

Methods: In this research, two unrelated patients were clinically diagnosed according to the criteria of proximal SMA.

A novel missense mutation of the ubiquitin protein ligase E3A gene in a patient with Angelman syndrome.

Background: Angelman syndrome (AS) is a neurogenetic disorder caused by an expression defect of the maternally inherited copy of ubiquitin protein ligase E3A (UBE3A) gene from chromosome 15. Although the most common genetic defects include maternal deletions of chromosome 15q11-13, paternal uniparental disomy and imprinting defect, mutations in the UBE3A gene have been identified in approximately 10% of AS patients.

Methods: A Chinese girl of 28 months presented clinical manifestation of AS.

[Genetic and clinical study on 17 cases of Angelman syndrome with deletion of 15q11-13].

Objective: Angelman syndrome (AS) is a neurodevelopmental genetic disorder that maps to 15q11-13. The primary phenotypes are attributable to loss of expression of imprinted UBE3A gene within this region which can arise by means of a number of mechanisms. The purpose of this study was to make a genetic diagnosis and to analyze the clinical features in suspected patients with AS.

[A study on genetic diagnosis for Angelman syndrome].

Objective: To study the genetic diagnosis of Angelman syndrome(AS), and provide information for clinic diagnosis and counseling to AS families.

Methods: Methylation specific-PCR (MS-PCR) was used for primary diagnosis of 16 clinically suspected AS cases, and linkage analysis by short tandem repeat (STR) was applied to detect the molecular genetic defect in the nuclear families.

Results: In this study, 10 AS patients were identified by MS-PCR, and 9 of them with maternal deletion in chromosome 15q11-q13, 1 with imprinting defect in chromosome 15q11-q13 were confirmed by STR linkage analysis.