Deletion analysis of SMN1 and NAIP genes in Southern Chinese children with spinal muscular atrophy / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Spinal muscular atrophy (SMA) is a disorder characterized by degeneration of lower motor neurons and occasionally bulbar motor neurons leading to progressive limb and trunk paralysis as well as muscular atrophy. Three types of SMA are recognized depending on the age of onset, the maximum muscular activity achieved, and survivorship: SMA1, SMA2, and SMA3. The survival of motor neuron (SMN) gene has been identified as an SMA determining gene, whereas the neuronal apoptosis inhibitory protein (NAIP) gene is considered to be a modifying factor of the severity of SMA. The main objective of this study was to analyze the deletion of SMN1 and NAIP genes in southern Chinese children with SMA. Here, polymerase chain reaction (PCR) combined with restriction fragment length polymorphism (RFLP) was performed to detect the deletion of both exon 7 and exon 8 of SMN1 and exon 5 of NAIP in 62 southern Chinese children with strongly suspected clinical symptoms of SMA. All the 32 SMA1 patients and 76% (13/17) of SMA2 patients showed homozygous deletions for exon 7 and exon 8, and all the 13 SMA3 patients showed single deletion of SMN1 exon 7 along with 24% (4/17) of SMA2 patients. Eleven out of 32 (34%) SMA1 patients showed NAIP deletion, and none of SMA2 and SMA3 patients was found to have NAIP deletion. The findings of homozygous deletions of exon 7 and/or exon 8 of SMN1 gene confirmed the diagnosis of SMA, and suggested that the deletion of SMN1 exon 7 is a major cause of SMA in southern Chinese children, and that the NAIP gene may be a modifying factor for disease severity of SMA1. The molecular diagnosis system based on PCR-RFLP analysis can conveniently be applied in the clinical testing, genetic counseling, prenatal diagnosis and preimplantation genetic diagnosis of SMA.

Mitochondrion and its related disorders: making a comeback / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

The great majority of genetic disorders are caused by defects in the nuclear genome. However, some significant diseases are the result of mitochondrial mutations. Because of the unique features of the mitochondria, these diseases display characteristic modes of inheritance and a large degree of phenotypic variability. Recent studies have suggested that mitochondrial dysfunction plays a central role in a wide range of age-related disorders and various forms of cancer.

Research advances in human mitochondrial DNA with aging and degenerative diseases / 浙江大学学报·医学版

The human mitochondrial genome consists of approximate 1500 genes, among which 37 are encoded by the mitochondrial DNA (mtDNA) and the remainder encoded in the nuclear DNA (nDNA). The mitochondria produces large amount of the cellular reactive oxygen species (ROS). ROS induces the mutations of mtDNA and mtDNA, which are associated with a wide range of age-related diseases including neurodegenerative diseases, cardiomyopathy, diabetes and various cancers.

PCR products with heterozygous mutations containing two types of heteroduplexes / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To confirm that PCR products with heterozygous mutations contain not only wide-type and mutant homoduplexes, but also two types of heteroduplexes.</p><p><b>METHODS</b>An insertion-deletion mutation in the exon 1 of KRT9 gene (497delAinsGGCT), which caused Chinese epidermolytic palmoplantar keratoderma (EPPK) was investigated by polymerase chain reaction (PCR), polyacrylamide gel electrophoresis (PAGE) and denaturing high-performance liquid chromatography(DHPLC).</p><p><b>RESULTS</b>Two heteroduplexes and two homoduplexes in the PCR product from the heterozygous mutation of the exon 1 of KRT9 (497delAinsGGCT) were detected.</p><p><b>CONCLUSION</b>PCR products from KRT9 gene with heterozygous mutations contain two types of heteroduplexes. It is without the need to perform heating and cooling PCR products obtained from heterozygous mutations in advance before the mutation screening steps such as denaturing gradient gel electrophoresis (DGGE), temperature gradient gel electrophoresis (TGGE), conformation-sensitive gel electrophoresis (CSGE), DHPLC and heteroduplex analysis (HA), etc.</p>

Present status of the molecular genetics in epidermolytic palmoplantar keratoderma / 中华医学遗传学杂志

In this article we reviewed the current researches on the molecular basis of epidermolytic palmoplantar keratoderma (EPPK) and the structure and function of the keratins with mutations that can cause inherited keratin disorders. Also summarized are seventeen mutations of keratin 9 in EPPK in different ethnic populations.

Association analysis between attention-deficit hyperactivity disorder and Val158Met polymorphism of catechol-O-methyltransferase gene / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate the association between attention-deficit hyperactivity disorder (ADHD) in Han Chinese children and Val158Met polymorphism of catechol-O-methyltransferase (COMT) gene caused by the missense mutation of G158A in exon 4.</p><p><b>METHODS</b>By using polymerase chain reaction-restriction fragment length polymorphisms the Val158Met polymorphism of COMT gene was tested in 117 children with the diagnosis of ADHD as defined by DSM-IV and in 105 healthy controls living in Shanghai.</p><p><b>RESULTS</b>The frequencies of A allele were 25.21% and 23.81% in the ADHD group and the health controls respectively, which showed no significant difference between the two groups (Chi2=0.5197, P>0.05). There was also no significant difference in the distribution of all genotypes of COMT gene between the ADHD patients and the controls (P>0.05).</p><p><b>CONCLUSION</b>It was suggested that for the Han Chinese children with ADHD in this study, there was no association between ADHD and Val158Met polymorphism of COMT gene.</p>