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N Niikawa

Publications and source records attributed to N Niikawa.

At least 73 records · Page 4Linked to original sources
PubMed1999

Digynic triploid infant surviving for 46 days.

We report on a triploid infant who survived for 46 days. She had severe intrauterine growth retardation, relative macrocephaly, and a small, noncystic placenta, which are manifestations compatible with type II phenotype. Cultured amniotic fluid cells, skin fibroblasts, cord blood, and peripheral blood lymphocytes all showed a nonmosaic 69,XXX karyotype. Analysis of chromosomal heteromorphisms and microsatellite DNA polymorphisms in the infant and her parents indicated that the extra haploid set in the infant resulted from nondisjunction at maternal second meiosis. Postzygotic, mitotic nondisjunction was ruled out because of the presence of both homozygous and heterozygous markers of maternal origin. A search of the literature demonstrated five triploid infants, including the girl we described, who survived 4 weeks or more, and the parental origin of whose triploidy was studied: four were digynic and one was diandric. These findings support the notion that type II triploids are digynic in parental origin and that they survive longer than type I, diandric triploids.

Abnormalities, Multiple↗
PubMed1999

ASC, a novel 22-kDa protein, aggregates during apoptosis of human promyelocytic leukemia HL-60 cells.

The cytoskeletal and/or nuclear matrix molecules responsible for morphological changes associated with apoptosis were identified using monoclonal antibodies (mAbs). We developed mAbs against Triton X-100-insoluble components of HL-60 cells pretreated with all-trans retinoic acid. In particular, one mAb recognized a 22-kDa protein that exhibited intriguing behavior by forming an aggregate and appearing as a speck during apoptosis induced by retinoic acid and other anti-tumor drugs. Cloning and sequencing of its cDNA revealed that this protein comprises 195 amino acids and that its C-terminal half has a caspase recruitment domain (CARD) motif, characteristic of numerous proteins involved in apoptotic signaling. We referred to this protein as ASC (apoptosis-associated speck-like protein containing a CARD). The ASC gene was mapped on chromosome 16p11.2-12. The antisense oligonucleotides of ASC were found to reduce the expression of ASC, and consequently, etoposide-mediated apoptosis of HL-60 cells was suppressed. Our results indicate that ASC is a novel member of the CARD-containing adaptor protein family.

Amino Acid Sequence↗
PubMed1999

Kabuki make-up syndrome is not caused by microdeletion close to the van der Woude syndrome critical region at 1q32-q41.

We reported on a 5-year-old Japanese girl with clinical manifestations of Kabuki make-up syndrome (KMS) and van der Woude syndrome (VWS). Since the concurrence of the two syndromes is known in four patients, including ours, it suggests a common cause. Assuming that the association of the two syndromes was caused by a microdeletion involving the putative KMS/VWS genes, we carried out fluorescence in situ hybridization and microsatellite analyses using PAC clones and dinucleotide repeat markers spanning the VWS1 critical region at 1q32-q41. No deletion was detected at the VWS1 critical region.

Abnormalities, Multiple↗
PubMed1999

In vivo kinetics of transduced cells in peripheral T cell-directed gene therapy: role of CD8+ cells in improved immunological function in an adenosine deaminase (ADA)-SCID patient.

We previously reported successful peripheral T cell-directed gene therapy in a boy with adenosine deaminase (ADA)-SCID. In the present study, to better understand the reconstitutive effect of this gene therapy on his immunological system, we investigated the in vivo kinetics and functional subsets of T cells in PBL. Apparent immunological improvements were obtained after infusion of transduced cells at more than 4 x 108 cells/kg/therapy/3 mo. Frequency of ADAcDNA-integrated cells in PBL, ADA activity in PBL and clinical improvement showed good correlation, even though CD8+ cells gradually became predominant in PBL. On the basis that polyethylene glycol (PEG)-ADA was maintained at the same dosage as before gene therapy, we consider that his immunological improvement resulted from the gene therapy itself. Most CD3+ cells in PBL after gene therapy expressed TCRalphabeta. Analysis of TCR repertoire based on TCR V region usage revealed no expansion of limited clones in his PBL. The T cell subset cells CD8+CDw60+ and CD8+CD27+CD45RA-, which are reported to provide substantial help to B cells, were maintained throughout the gene therapy. Furthermore, his reconstituted peripheral T cells helped normal B cells to produce substantial IgG in vitro. Expression of both Th1- and Th2-type cytokine genes was induced in his reconstituted T cells at the same comparably high level as in normal subjects. Collectively, these results provide evidence of persistent and distinct functions of transduced cells in this patient's PBL after gene therapy.

Adenosine Deaminase↗
PubMed1999

Mutchinick syndrome in a Japanese girl.

We report on a 7-year-old Japanese girl with Mutchinick syndrome, a rare congenital malformation syndrome described in a pair of Argentinean sisters and a pair of German brothers; both originating from the same geographic region in the former East Prussia. The girl we describe had most of the clinical manifestations of the syndrome, including growth and developmental retardation, and craniofacial anomalies with microcephaly, hypertelorism, a broad straight nose, low-set malformed ears, and a wide, tented mouth. She also had the following hitherto undescribed manifestations: ventricular septal defect, palmoplantar hyperkeratosis, bilateral partial soft-tissue syndactyly of second and third toes, and megaloureters. The occurrence of the syndrome in a Japanese girl indicates that the syndrome is not restricted to the descendants of individuals from a confined region in northeastern Europe.

Abnormalities, Multiple↗
PubMed1999

Cloning of the peroxiredoxin gene family in rats and characterization of the fourth member.

Peroxiredoxin (PRx) exhibits thioredoxin-dependent peroxidase activity and constitutes a family of proteins. Four members of genes from rat tissues were isolated by PCR using degenerated primers based on the sequences which encode a pair of highly conserved Cys-containing domains, and were then cloned to full-length cDNAs. These included two genes which have previously been isolated in rats, PRx I and PRx II, and two rat homologues of PRx III and PRx IV. We showed, for the first time, the simultaneous expression of all four genes in various rat tissues by Northern blotting. Since a discrepancy exists regarding cellular distribution, we further characterized PRx IV by expressing it in COS-1 cells. This clearly demonstrates that PRx IV is a secretory form and functions within the extracellular space.

Amino Acid Sequence↗
PubMed1999

Trizygotic pregnancy consisting of two fetuses and a complete hydatidiform mole with dispermic androgenesis.

A triplet pregnancy in a 23-year-old woman was terminated at 15 weeks of gestation because of her severe hypertension, lung edema, and secondary hyperthyroidism. The pregnancy consisted of a hydatidiform mole with a 46,XY karyotype and two fetuses each with 46,XX and a 46,XY karyotype. To determine the zygosity and genetic origin of the mole and fetuses, PCR- and computer-assisted genotyping were performed at 27 CA-repeat marker loci that were distributed evenly over the genome. As a result, genotypes of the three pregnancy products were distinct from each other, indicating that the triplets were trizygotic. The mole lacked any maternal alleles but inherited both of the paternal alleles and/or one paternal allele in duplicate. This, along with the XY sex chromosome constitution, indicated that the mole resulted from dispermic androgenesis. The mother developed a persistent trophoblastic tumor thereafter.

Abortion, Therapeutic↗
PubMed1999

Repeat-directed isolation of a novel gene preferentially expressed from the maternal allele in human placenta.

Using a repetitive sequence of tandemly arrayed pentanucleotides in the human H19 3'-flanking region, we isolated a phage clone (lambda PEN11) which localized to chromosome 11p15.5. The lambda PEN11 phage encodes a 2.3-kb cDNA consisting of seven exons at least. The gene was mainly expressed in brain and pancreas (and less abundantly in testis), and demonstrated differential allele usage, with maternal expression being predominant in placenta, which indicates the gene is an atypical imprinted gene. While the pentamer repeat might contribute to this effect, it is also possible that the differential allele usage might reflect the local chromosomal structure known as the imprinting domain.

Alleles↗
PubMed1999

Isolation and localization of an IDDMK1,2-22-related human endogenous retroviral gene, and identification of a CA repeat marker at its locus.

We intended to confirm genetically the involvement of the IDDMK1,2-22 gene in the pathogenesis of insulin-dependent diabetes mellitus (IDDM). For this purpose, we isolated a human endogenous retrovirus gene, possibly corresponding to IDDMK1,2-22. The isolated gene showed 99.8% and 99.7% homologies in nucleotide sequences to a part of the env region and of the 3'-LTR region, respectively, compared to those of IDDMK1,2-22 deposited in GenBank. The gene also showed a close relation to HERV-K18, of which the 3'-LTR sequence gave 99.5% homology. It seemed likely that these genes represented the same single gene. The newly isolated gene was present in the first intron of the CD48 gene and was located on chromosome 1q21.2-q22. A CA repeat marker was found approximately 20 kb upstream from the 5'-end of the 5'-LTR of the gene.

Chromosome Mapping↗
PubMed1999

Methylation imprinting of H19 and SNRPN genes in human benign ovarian teratomas.

In humans, studies of female germ cells are very limited by ethics. The current study investigated the usefulness of benign ovarian teratomas as a substitute for ova in analyses of imprinted genes. Twenty-five human benign ovarian teratomas were typed with 45 microsatellite DNA markers and classified according to their genotypic features. Two oppositely imprinted genes, H19 and SNRPN, were then chosen for analysis of their methylation states in these tumors. These analyses revealed that benign ovarian teratomas consist of a mixture of genetically and epigenetically heterogeneous cell populations. In contrast to previous reports, we could document only one case rising from germ cells by meiosis-II nondisjunction. H19 and SNRPN were methylated in individual teratomas to various degrees, ranging from normal somatic cell to expected ovum levels. The allele with residual methylation of H19 was consistent with that methylated in the patient's blood DNA, thus being of paternal origin. Degrees of H19 hypomethylation and SNRPN hypermethylation increased as the cellular origin of the tumors advanced in oogenesis and were closely correlated in individual teratomas. These results could be best explained by the assumption that the primary imprinting is a progressively organized process and suggest that the establishment of primary imprints on different genes might be mechanistically linked, even when those genes are oppositely imprinted.

Autoantigens↗
PubMed1999

Paroxysmal kinesigenic choreoathetosis locus maps to chromosome 16p11.2-q12.1.

Paroxysmal kinesigenic choreoathetosis (PKC), the most frequently described type of paroxysmal dyskinesia, is characterized by recurrent, brief attacks of involuntary movements induced by sudden voluntary movements. Some patients with PKC have a history of infantile afebrile convulsions with a favorable outcome. To localize the PKC locus, we performed genomewide linkage analysis on eight Japanese families with autosomal dominant PKC. Two-point linkage analysis provided a maximum LOD score of 10.27 (recombination fraction [theta] =.00; penetrance [p] =.7) at marker D16S3081, and a maximum multipoint LOD score for a subset of markers was calculated to be 11.51 (p = 0.8) at D16S3080. Haplotype analysis defined the disease locus within a region of approximately 12.4 cM between D16S3093 and D16S416. P1-derived artificial chromosome clones containing loci D16S3093 and D16S416 were mapped, by use of FISH, to 16p11.2 and 16q12.1, respectively. Thus, in the eight families studied, the chromosomal localization of the PKC critical region (PKCR) is 16p11.2-q12.1. The PKCR overlaps with a region responsible for "infantile convulsions and paroxysmal choreoathetosis" (MIM 602066), a recently recognized clinical entity with benign infantile convulsions and nonkinesigenic paroxysmal dyskinesias.

Adolescent↗
PubMed1999

LIT1, an imprinted antisense RNA in the human KvLQT1 locus identified by screening for differentially expressed transcripts using monochromosomal hybrids.

Mammalian imprinted genes are frequently arranged in clusters on particular chromosomes. The imprinting cluster on human chromosome 11p15 is associated with Beckwith-Wiedemann syndrome (BWS) and a variety of human cancers. To clarify the genomic organization of the imprinted cluster, an extensive screen for differentially expressed transcripts in the 11p15 region was performed using monochromosomal hybrids with a paternal or maternal human chromosome 11. Here we describe an imprinted antisense transcript identified within the KvLQT1 locus, which is associated with multiple balanced chromosomal rearrangements in BWS and an additional breakpoint in embryonal rhabdoid tumors. The transcript, called LIT1 (long QT intronic transcript 1), was expressed preferentially from the paternal allele and produced in most human tissues. Methylation analysis revealed that an intronic CpG island was specifically methylated on the silent maternal allele and that four of 13 BWS patients showed complete loss of maternal methylation at the CpG island, suggesting that antisense regulation is involved in the development of human disease. In addition, we found that eight of eight Wilms' tumors exhibited normal imprinting of LIT1 and five of five tumors displayed normal differential methylation at the intronic CpG island. This contrasts with five of six tumors showing loss of imprinting of IGF2. We conclude that the imprinted gene domain at the KvLQT1 locus is discordantly regulated in cancer from the imprinted domain at the IGF2 locus. Thus, this positional approach using human monochromosomal hybrids could contribute to the efficient identification of imprinted loci in humans.

Animals↗
PubMed1999

Mapping of the alpha-1,6-fucosyltransferase gene, FUT8, to human chromosome 14q24.3.

Alpha-1,6-Fucosyltransferase (alpha1,6FucT) is involved in the biosynthesis of asparagine-linked glycoprotein oligosaccharides. In this study, we isolated a genomic clone for the human alpha1,6FucT gene (FUT8) and mapped it by fluorescence in situ hybridization to chromosome 14q24.3. This study suggests a distinct localization of FUT8 from genes for other human fucosyltransferases reported to date.

Chromosome Mapping↗
PubMed1999

The structural organization of the human aldehyde reductase gene, AKR1A1, and mapping to chromosome 1p33-->p32.

Genomic DNA encoding for human aldehyde reductase (AKR1A1), a member of the aldo-keto reductase superfamily, was isolated and characterized. The genomic DNA is approximately 16 kb in length and contains eight exons which encode the entire coding region and the 3'-untranslated sequences. AKR1A1 was localized on chromosome 1p33-->p32 by fluorescence in situ hybridization.

3' Untranslated Regions↗
PubMed1999

[Molecular-genetic approach to congenital malformation syndromes].

The causes of congenital malformation syndromes had long remained obscure, because their biochemical bases were unknown. However, with recently developed reverse-genetic and/or Human Genome Project-derived technology, we have been able to approach such disorders. These new methods include positional cloning techniques, candidate gene approach and positional candidate strategies. Among them, positional cloning has become most reliable nowadays, and three ways are mainly available to obtain position information of disease genes, i.e., data from linkage analysis of disease families; comparative maps between different species; breakpoints of disease-related de novo chromosomal translocations. I present here some examples for each strategy: a large kindred with mesomelic dysplasia Kantaputra type for linkage data, and its seemingly allelic bone dysplasia associated with t (2; 8) for positional cloning that starts from a chromosomal translocation; Waardenburg syndrome for candidate gene approach; and the p57KIP2 gene for positional candidate approach to Wiedemann-Beckwith syndrome. I finally emphasize that a human link composed of general physicians, molecular geneticists and clinical researchers is essential to reach a goal of reverse genetics. Without such a goal, we can neither understand the genesis of diseases nor develop their therapy.

Beckwith-Wiedemann Syndrome↗