OBJECTIVE: To analyze the pathogenic variants of the KIF1A gene and its corresponding protein structure in an autism spectrum disorder (ASD) family trio carrying harmful missense variants in the KIF1A gene. METHODS: The peripheral blood DNA of the patient and his parents was extracted and sequenced using whole exome sequencing (WES) technology and verified by Sanger sequencing. Bioinformatics software SIFT, PolyPhen-2, Mutation Taster, and CADD software were used to analyze the harmfulness and conservation of variants. The Human Brain Transcriptome (HBT) database was used to analyze the expression of the KIF1A gene in the brain. PredictProtein and SWISS-MODEL were further used to predict the secondary structure and tertiary structure of KIF1A wild-type protein and variant protein. PyMOL V2.4 was utilized to investigate the change of hydrogen bond connection after protein variant. RESULTS: The WES sequencing revealed a missense variant c.664A>C (p.Asn222His) in the child's KIF1A gene, and this variant was a de novo variant. The harmfulness prediction results suggest that this variant is harmful. By analyzing expression level of KIF1A gene in the brain. It is found that KIF1A gene widely expressed in various brain regions during embryonic development. By analyzing the variant protein structure, the missense variant of KIF1A will cause many changes in the secondary structure of protein, such as alpha-helix, beta-strand, and protein binding domain. The connection of hydrogen bond and spatial structure will also change, thereby changing the original biological function. CONCLUSION The KIF1A gene may be a risk gene for ASD.
Autism Spectrum Disorder/genetics* ; Child ; Female ; Humans ; Kinesin/genetics* ; Mutation ; Mutation, Missense ; Pregnancy ; Protein Domains ; Whole Exome Sequencing

OBJECTIVE: To carry out single nucleotide polymorphism (SNP)-based chromosome microarray analysis (CMA) for a boy featuring global developmental delay. METHODS: The SNP array was conducted for the child, and real-time PCR was used to validate its result and identify the origin of pathological copy number variants. RESULTS: SNP array revealed that the patient has carried a de novo 2.5 Mb duplication at 2q22.3q23.3, which encompassed ACVR2A, KIF5C, MBD5, EPC2, LYPD6, LYPD6, MMADHC and ORC4 genes. Literature review suggested that the MBD5 gene from the duplicated region may have predisposed to the global developmental delay shown by the girl. CONCLUSION The patient's clinical phenotype was consistent to that of 2q23 duplication, for which the MBD5 gene may play a key role. CMA has provided an important tool for the diagnosis of patients with global developmental delay.
Child ; Chromosome Deletion ; Chromosomes, Human, Pair 2 ; DNA Copy Number Variations ; DNA-Binding Proteins ; genetics ; Female ; Genotype ; Humans ; Kinesin ; Phenotype

OBJECTIVETo determine the mutation responsible for the congenital fibrosis of the extraocular muscles type I(CFEOM1) in a Chinese family.

METHODSDirect sequencing of exons 20 and 21 in the KIF21A gene was performed for the proband. The mutation c.2860C to T in exon 21 was examined by allele specific-PCR (AS-PCR) analysis in other family members. Haplotype analysis was performed using four STR markers (D12S1668, D12S2194, D12S331 and D12S1048).

RESULTSA heterozygous mutation c.2860C to T in the KIF21A gene was identified in all three affected members with CFEOM1. Haplotype analysis suggested that the mutation might derive from maternal germline mosaicism.

CONCLUSIONThis Chinese family with CFEOM1 may be caused by a c.2860C to T mutation in the KIF21A gene.

Alleles ; Asian Continental Ancestry Group ; genetics ; Base Sequence ; Child ; China ; Exons ; Female ; Fibrosis ; Haplotypes ; Humans ; Kinesin ; genetics ; Mutation ; genetics ; Oculomotor Muscles ; metabolism ; pathology ; Pedigree ; Phenotype ; Syndrome

The integrity of blood vessels controls vascular permeability and extravasation of blood cells, across the endothelium. Thus, the impairment of endothelial integrity leads to hemorrhage, edema, and inflammatory infiltration. However, the molecular mechanism underlying vascular integrity has not been fully understood. Here, we demonstrate an essential role for A-kinase anchoring protein 12 (AKAP12) in the maintenance of endothelial integrity during vascular development. Zebrafish embryos depleted of akap12 (akap12 morphants) exhibited severe hemorrhages. In vivo time-lapse analyses suggested that disorganized interendothelial cell-cell adhesions in akap12 morphants might be the cause of hemorrhage. To clarify the molecular mechanism by which the cell-cell adhesions are impaired, we examined the cell-cell adhesion molecules and their regulators using cultured endothelial cells. The expression of PAK2, an actin cytoskeletal regulator, and AF6, a connector of intercellular adhesion molecules and actin cytoskeleton, was reduced in AKAP12-depleted cells. Depletion of either PAK2 or AF6 phenocopied AKAP12-depleted cells, suggesting the reduction of PAK2 and AF6 results in the loosening of intercellular junctions. Consistent with this, overexpression of PAK2 and AF6 rescued the abnormal hemorrhage in akap12 morphants. We conclude that AKAP12 is essential for integrity of endothelium by maintaining the expression of PAK2 and AF6 during vascular development.
A Kinase Anchor Proteins/*genetics/metabolism ; Animals ; Blood Vessels/abnormalities/*embryology/metabolism ; Cell Cycle Proteins/genetics/metabolism ; Down-Regulation ; Embryo, Nonmammalian/abnormalities/*blood supply/embryology/metabolism ; Gene Deletion ; *Gene Expression Regulation, Developmental ; Hemorrhage/*embryology/genetics/metabolism ; Human Umbilical Vein Endothelial Cells ; Humans ; Intercellular Junctions/genetics/metabolism/ultrastructure ; Kinesin/genetics/metabolism ; Myosins/genetics/metabolism ; Zebrafish/*embryology/genetics ; p21-Activated Kinases/genetics/metabolism

Recently, rearranged during transfection (RET) fusions have been identified in approximately 1% of non-small cell lung cancer (NSCLC). To know the prevalence of RET fusion genes in Korean NSCLCs, we examined the RET fusion genes in 156 surgically resected NSCLCs using a reverse transcriptase polymerase chain reaction. Two KIF5B-RET fusions and one CCDC6-RET fusion were identified. All three patients were females and never smokers with adenocarcinomas. RET fusion genes were mutually exclusive from EGFR, KRAS mutations and EML4-ALK fusion. RET fusion genes occur 1.9% (3 of 156) of surgically treated NSCLC patients in Koreans.
Asian Continental Ancestry Group/*genetics ; Carcinoma, Non-Small-Cell Lung/epidemiology/*genetics/surgery ; Cytoskeletal Proteins/genetics ; Female ; Humans ; Kinesin/genetics ; Lung Neoplasms/epidemiology/*genetics/surgery ; Middle Aged ; Oncogene Proteins, Fusion/*genetics ; Proto-Oncogene Proteins c-ret/*genetics ; Republic of Korea/epidemiology ; Sequence Analysis, DNA

Although it has been suggested that kinesin family member 14 (KIF14) has oncogenic potential in various cancers, including hepatocellular carcinoma (HCC), the molecular mechanism of this potential remains unknown. We aimed to elucidate the role of KIF14 in hepatocarcinogenesis by knocking down KIF14 in HCC cells that overexpressed KIF14. After KIF14 knockdown, changes in tumor cell growth, cell cycle and cytokinesis were examined. We also examined cell cycle regulatory molecules and upstream Skp1/Cul1/F-box (SCF) complex molecules. Knockdown of KIF14 resulted in suppression of cell proliferation and failure of cytokinesis, whereas KIF14 overexpression increased cell proliferation. In KIF14-silenced cells, the levels of cyclins E1, D1 and B1 were profoundly decreased compared with control cells. Of the cyclin-dependent kinase inhibitors, the p27Kip1 protein level specifically increased after KIF14 knockdown. The increase in p27Kip1 was not due to elevation of its mRNA level, but was due to inhibition of the proteasome-dependent degradation pathway. To explore the pathway upstream of this event, we measured the levels of SCF complex molecules, including Skp1, Skp2, Cul1, Roc1 and Cks1. The levels of Skp2 and its cofactor Cks1 decreased in the KIF14 knockdown cells where p27Kip1 accumulated. Overexpression of Skp2 in the KIF14 knockdown cells attenuated the failure of cytokinesis. On the basis of these results, we postulate that KIF14 knockdown downregulates the expression of Skp2 and Cks1, which target p27Kip1 for degradation by the 26S proteasome, leading to accumulation of p27Kip1. The downregulation of Skp2 and Cks1 also resulted in cytokinesis failure, which may inhibit tumor growth. To the best of our knowledge, this is the first report that has identified the molecular target and oncogenic effect of KIF14 in HCC.
Carcinoma, Hepatocellular/*metabolism ; Cyclin-Dependent Kinase Inhibitor p27/genetics/*metabolism ; Cyclins/genetics/metabolism ; *Cytokinesis ; Gene Silencing ; Hep G2 Cells ; Humans ; Kinesin/genetics/*metabolism ; Liver Neoplasms/*metabolism ; Oncogene Proteins/genetics/*metabolism ; Proteasome Endopeptidase Complex/metabolism ; RNA, Messenger/genetics/metabolism ; S-Phase Kinase-Associated Proteins/genetics/metabolism ; *Ubiquitination