Mutation screening of SCN1A 3′ untranslated region on Dravet syndrome patients and functional analysis of the variant / 中华神经科杂志

Objective To conduct mutation screening of SCN1A 3′ untranslated region (UTR) on Dravet syndrome (DS) patients without mutations in the SCN1A coding region and promoter region, and functional analysis of the variant from DS patients.Methods Twenty-eight DS patients without mutations in the SCN1A coding region and promoter region were screened for SCN1A 3′ UTR mutations using PCR and direct sequencing.Functional analysis of the detected mutation was done via luciferase assay, mRNA stability analysis and RNA electrophoretic mobility shift assay (RNA-EMSA).Results A novo variant (c.*20A>G) in SCN1A 3′ UTR was found in one DS patient.The variant (c.*20A>G) reduced the luciferase gene xpression by 30% through increasing the affinity of pluripotent embryonal carcinoma cell line NT2/cytoplasmic protein binding and reducing luciferase gene mRNA stability (t=8.5,P<0.01).Conclusions A functional variant was detected from one patient with DS.This variant negatively regulated the gene expression by increasing the affinity of pluripotent embryonal carcinoma cell line NT2/cytoplasmic protein binding and reducing mRNA stability.

Clinical and molecular genetic studies of a Chinese family with oculopharyngeal muscular dystrophy / 中国神经精神疾病杂志

Objective To investigate the clinical and molecular genetic changes in a Chinese family with oculopha?ryngeal muscular dystrophy(OPMD). Methods We collected the clinical data of the familial members and blood sam?ples from all available 16 familial members, including the proband. The samples were analyzed using modified poly?merase chain reaction amplification and direct sequence analysis. Results Male OPMD patients initially presented with ptosis, followed by pronunciation difficulty, dysphagia and limb weakness whereas female OPMD patients initially pre?sented with swallowing difficulty. Genetic test revealed the abnormal expansions of the GCG trinucleotide repeat from GCG6 to GCG10 in PABPN1 gene in 10 familial members. Conclusions The genetic test and prenatal diagnosis is the key for the prevention treatment of oculopharyngeal muscular dystrophy. The ptosis of eyelid may be the initial symptom for the male patients of oculopharyngeal muscular dystrophy with (GCG)10 mutation.

Genetic analysis of 5'-untranslated region of voltage-gated sodium channel alpha 1-subunit gene in Dravet syndrome / 中华神经科杂志

Objective To screen and analyze nucleotide variants in 5'-untranslated region(5'-UTR)in voltage-gated sodium channel α1-subunit gene(SCN1A)in patients with Dravet syndrome and to evaluate the association of the variants with disease.Methods Peripheral blood of 24 patients with Dravet syndrome and 100 unrelated normal persons were collected and genomic DNA was extracted.PCR-sequencing of SCN1 A 5'-UTR in these DNA was performed.To evaluate the possibility of mutation inducing disease,bioinformatics analysis was applied to analyze the conservation of the sequences around the mutation site and predict the potential transcription elements.Results The nucleotide variant of 166.642.520G→A in exon 2 was identified in two patients,but not in normal controls.The mutation was a de novo mutation in a patient with early-onset.In the second proband,the mutation was also carried by his clinically asymptomatic mother.The nucleotide site 166.642.520 was moderately conserved in mammals(62.5%).The average nucleotide identity rate between human and other mammals species in the region adjacent to 166.642.520 was 88.5%.Two potential transcription regulatory elements were predicted on the sequence with the mutation of 166.642.520G>A,and only one on the sequence with wild-type.Conclusions The mutation 166.642.520G>A may be associated with Dravet syndrome and further studied should be performed to verify it and demonstrate its pathogenic mechanisms.

De novo sodium channel αl-subuult mutation of monozygotic twins with borderland severe myoclonic epilepsy in infancy / 中华神经科杂志

Objective To study the sodium channel α1-subunit (SCN1A) gene in a pair of monozygotic twins with borderland severe myoclonic epilepsy in infancy (SMEB) and its characteristic of clinical manifestations. Methods The clinical features of 2 monozygotic twins were summarized. All 26 exons of SCNIA genes were screened with denaturing high performance liquid chromatography (DHPLC), and direct sequence analysis was performed on those with abnormal elution peak. Results The proband and her sister showed typical clinical features of SMEB. The same heterozygous mutations on exon 26 which caused the related amino acid change were found among them (c. 5348C > T, A1783E). Conclusion Monozygotic twins with similar clinical phenotype of SMEB have same SCN1A gene mutation.

Mosaic SCN1A mutation in a family with partial epilepsy with febrile seizures plus / 中华神经科杂志

Objective To study the SCN1A gene in a family with partial epilepsy with febrile seizures plus ( PEFS+ ) and its characteristics of inheritance. Methods The clinical features of the 2 patients and their father were summarized. All 26 exons of SCN1A gene were screened with denaturing high performance liquid chromatography (DHPLC), and direct sequence analysis was pedormed on those with abnormal elution peak. Pyrosequencing was subsequently performed in those without abnormality in direct sequence analysis. Results The proband and his sister had the phenotype of PEFS+ . The same heterozygous mutations (AS768G) on exon 26 which caused the related amino acid change (Q1923R) were found among them. Their father had frequent febrile seizures (FS) in childhood, and seizures stopped spontaneously. No abnormality was found in direct sequence but mosaic mutation in the same site was discovered with pyrosequencing (mutation quantity was 25% ). Conclusions The mutatin of SCN1A could cause partial epilepsy. PEFS+ could be inherited, the relatives carrying the affected gene may have mild clinical symptoms, possibly resulting from the low concentration of the mutated gene due to mosaic mutation.