ABSTRACT. A variant of hepatitis B virus (HBV) having a specific mutation within the S gene has been found to infect vaccinees. To know whether similar variants were involved in Japan, we analyzed two cases of maternal transmission of HBV in infants immunized with hepatitis B immune globulin and hepatitis B vaccine. DNA clones of HBV S genes were propagated from patients and family members and sequenced. In one family, the DNA clones from the baby patient had a Gly-to-Arg mutation at the 145th codon of the S gene, whereas those from her mother had no such mutations. In the other family, all the DNA clones obtained from the two infected children had the 145th codon intact, but they had a missense mutation at the 126th codon of the S gene, causing an amino acid substitution of Asn for Thr or Ile. This same mutation was observed in 12 of 17 clones of DNA obtained from their mother. In comparison with the wild type HBV-derived hepatitis B surface antigen, the two types of S gene mutations, either at the 145th or the 126th codon, were associated with a significant decrease in the antigenicity of some determinants on the hepatitis B surface antigen, measured by MAb. Amino acid substitution at these sites, therefore, would have induced the escape from conventional vaccines that were S gene products of wild type HBV and also from hepatitis B immune globulin, whose main components were probably also antibodies against the S gene products expressed by wild type HBV. (Pediatr Res 32: [264][265][266][267][268] 1992) Abbreviations HBV, hepatitis B virus HBsAg, hepatitis B surface antigen anti-HBs, antibody to HBsAg HBeAg, hepatitis B e antigen anti-HBc, antibody to hepatitis B core antigen HBIG, hepatitis B immune globulin A492, absorbance at 492 nm in ELISA PHA, passive hemagglutination PCR, polymerase chain reaction

A major goal of current human genome-wide studies is to identify the genetic basis of complex disorders. However, the availability of an unbiased, reliable, cost efficient and comprehensive methodology to analyze the entire genome for complex disease association is still largely lacking or problematic. Therefore, we have developed a practical and efficient strategy for whole genome association studies of complex diseases by charting the human genome at 100 kb intervals using a collection of 27,039 microsatellites and the DNA pooling method in three successive genomic screens of independent case-control populations. The final step in our methodology consists of fine mapping of the candidate susceptible DNA regions by single nucleotide polymorphisms (SNPs) analysis. This approach was validated upon application to rheumatoid arthritis, a destructive joint disease affecting up to 1% of the population. A total of 47 candidate regions were identified. The top seven loci, withstanding the most stringent statistical tests, were dissected down to individual genes and/or SNPs on four chromosomes, including the previously known 6p21.3-encoded Major Histocompatibility Complex gene, HLA-DRB1. Hence, microsatellite-based genome-wide association analysis complemented by end stage SNP typing provides a new tool for genetic dissection of multifactorial pathologies including common diseases.

Cytoplasmic protein aggregates are one of the pathological hallmarks of neurodegenerative disorders, including amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD). Several RNA-binding proteins have been identified as components of inclusion bodies. Developmentally regulated RNA-binding protein 1 (Drb1)/RNA-binding motif protein 45 is an RNA-binding protein that was recently described as a component in ALS-and FTLD-related inclusion bodies. However, the molecular mechanism underlying cytoplasmic Drb1 aggregation remains unclear. Here, using an in vitro cellular model, we demonstrated that Drb1 co-localizes with cytoplasmic aggregates mediated by TAR DNA-binding protein 43, a major component of ALS and FTLD-related inclusion bodies. We also defined the domains involved in the subcellular localization of Drb1 to clarify the role of Drb1 in the formation of cytoplasmic aggregates in ALS and FTLD. Drb1 predominantly localized in the nucleus via a classical nuclear localization signal in its carboxyl terminus and is a shuttling protein between the nucleus and cytoplasm. Furthermore, we identify a double leucine motif serving as a nuclear export signal. The Drb1 mutant, presenting mutations in both nuclear localization signal and nuclear export signal, is prone to aggregate in the cytoplasm. The mutant Drb1-induced cytoplasmic aggregates not only recruit TAR DNA-binding protein 43 but also decrease the mitochondrial membrane potential. Taken together, these results indicate that perturbation of Drb1 nuclearcytoplasmic trafficking induces toxic cytoplasmic aggregates, suggesting that mislocalization of Drb1 is involved in the cause of cytotoxicity in neuronal cells. ALS,2 one of the most devastating and untreatable neurodegenerative diseases, affects motor neurons selectively with relentless progression and causes respiratory failure within 2-5 years from onset. Although 5-10% of ALS cases are familial, ϳ90% of cases are sporadic with unknown etiology (1). In contrast, frontotemporal lobar degeneration (FTLD) is a group of neurodegenerative diseases that affect frontal and temporal cortices with characteristic cognitive defects such as personality and behavioral changes as well as progressive deterioration of language skills (2). A subgroup of patients presents overlapped clinical characteristics of ALS and FTLD. Cytoplasmic inclusion bodies in neuronal cells are a common pathological hallmark in ALS and FTLD, implying that a common etiological pathway exists in ALS and FTLD pathogenesis (1, 3). TAR DNA-binding protein 43 (TDP-43), an RNA-binding protein, was the first protein identified in cytoplasmic inclusion bodies in most sporadic ALS and several FTLD cases (4, 5). Since then, other RNA-binding proteins, such as fused in sarcoma/translated in liposarcoma (FUS/TLS), and heterogeneous nuclear ribonucleoproteins were also identified as components of cytoplasmic inclusion bodies. Because disease-associated mutations in the TDP-43 or FUS/TLS gene were identified in several familial ALS and F...

Interstitial deletion of 12q21 has been reported in four cases, which share several common clinical features, including intellectual disability (ID), low-set ears, and minor cardiac abnormalities. Comparative genomic hybridization (CGH) analysis using the Agilent Human Genome CGH 180K array was performed with the genomic DNA from a two-year-old Japanese boy with these symptoms, as well as hypoplasia of the corpus callosum. Consequently, a 14 Mb deletion at 12q21.2-q21.33 (nt. 77 203 574–91 264 613 bp), which includes 72 genes, was detected. Of these, we focused on LIN7A, which encodes a scaffold protein that is important for synaptic function, as a possible responsible gene for ID, and we analyzed its role in cerebral cortex development. Western blotting analyses revealed that Lin-7A is expressed on embryonic day (E) 13.5, and gradually increases in the mouse brain during the embryonic stage. Biochemical fractionation resulted in the enrichment of Lin-7A in the presynaptic fraction. Suppression of Lin-7A expression by RNAi, using in utero electroporation on E14.5, delayed neuronal migration on postnatal day (P) 2, and Lin-7A-deficient neurons remained in the lower zone of the cortical plate and the intermediate zone. In addition, when Lin-7A was silenced in cortical neurons in one hemisphere, axonal growth in the contralateral hemisphere was delayed; development of these neurons was disrupted such that one half did not extend into the contralateral hemisphere after leaving the corpus callosum. Taken together, LIN7A is a candidate gene responsible for 12q21-deletion syndrome, and abnormal neuronal migration and interhemispheric axon development may contribute to ID and corpus callosum hypoplasia, respectively.

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