Correlation between human seizure-related gene 6 variants and idiopathic generalized epilepsy in a Southern Chinese Han population

This study sought to analyze the genotype and gene mutations of human seizure-related gene 6 in 98 patients with idiopathic generalized epilepsy （non-febrile seizures）, who were selected from three generations of the Chinese Han population living in Shanghai, Zhejiang Province, Wuxi of Jiangsu Province, and Jiangxi Province of Southern China. Twenty-six patients＇ parents were available as a first-degree relatives group and 100 biologically unrelated healthy controls were collected as the control group. Based on the age of onset and seizure type, the patients were divided into six subgroups. Polymerase chain reaction and DNA direct sequencing analysis showed that the most frequent mutations c. 1249dupC （p.Gly418Argfx31 ） and c.1636A 〉 G （p.Thr546Ala） were detected in some idiopathic generalized epilepsy patients and tl^eir asymptomatic first-degree relatives （30.6% vs. 19.2% and 11.2% vs. 26.9%）. A novel mutation c.1807G 〉A （p.Val603Met） was found in a patient with late-onset idiopathic generalized epilepsy. There was no significant difference in the incidence of these three mutations among the different subgroups of idiopathic generalized epilepsy and controls. Thus, further analysis of a larger population is needed to confirm the assumption that human seizure-related gene 6 is a susceptibility gene for idiopathic generalized epilepsy with various sub-syndromes.

Seizure-related 6,a brain-specific expression gene,is highly expressed in the human cerebellum

Epilepsy is a complex, Mendelian disease, and most cases are sporadic. Genomic comparisons of tissue from identified monogenic epilepsies with multigenic and acquired syndromes could ultimately reveal crucial molecular neuropathology for an epileptic phenotype. In the present study, a novel gene, human seizure-related （hSEZ）-6, was isolated from a human brain cDNA library. hSEZ-6 comprises 17 exons and spans a region of at least 55.6 kb, which was localized to 17q 12 by radiation hybridization, hSEZ-6 exhibits two isoform types, hSEZ-6A and hSEZ-6B, which encode 996 and 995 amino acids, respectively. The two putative hSEZ-6 proteins contain similar motifs and share 82% and 84% identity with mouse SEZ-6A protein, whose expression level increased in mouse cerebral cortex-derived cells treated with a convulsant drug, pentylentetrazole. Northern blot analysis demonstrated that hSEZ-6 is expressed highly in the cerebellum and in nucleus of the extrapyramidal system, such as the caudate nucleus and putamen. Reverse transcription polymerase chain reaction revealed that hSEZ-6 is expressed in neurons rather than gliocytes, which suggests that hSEZ-6 is a seizure-related gone.

Large deletions within the spinal muscular atrophy gene region in a patient with spinal muscular atrophy type 3

Spinal muscular atrophy （SMA） is an autosomal recessive neuromuscular disorder characterized by degeneration and loss of anterior horn cells in the spinal cord and brain stem nuclei, leading to progressive limb and trunk paralysis and muscular atrophy. Depending on the age of onset and maximum muscular function achieved, SMA is recognized as SMA1, SMA2, SMA3 or SMA4, and most patients have a deletion or truncation of the survival motor neuron 1 （SMN1） gene. In this report, we present a patient with a mild SMA phenotype, SMA3, and define his genetic abnormality. Tetra-primer amplification refractory mutation system PCR combined with restriction fragment length polymorphism analysis and array comparative genomic hybridization were used to determine the genetic variations in this patient. A 500 kb deletion in chromosome 5q13.2, including homozygous deletion of neuronal apoptosis inhibitory protein, and heterozygous deletion of occludin and B-double prime 1 was identified. This SMA region deletion did not involve SMN, indicating that SMN was likely to function normally. The phenotype was dependent of the large deletion and neuronal apoptosis inhibitory protein, occludin and B-double prime 1 may be candidate genes for SMA3.