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Nippon rinsho. Japanese journal of clinical medicine 10/2006; Suppl 3:488-91.
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Toru Udaka,
Kenji Kurosawa,
Kosuke Izumi,
Shinobu Yoshida, Masato Tsukahara,
Nobuhiko Okamoto,
Chiharu Torii,
Rika Kosaki,
Mitsuo Masuno,
Noboru Hosokai,
Takao Takahashi,
Kenjiro Kosaki
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ABSTRACT: Rubinstein-Taybi syndrome (RTS, MIM 180849) is a multiple malformation syndrome characterized by growth retardation, developmental delay, and dysmorphic features, including down-slanting palpebral fissures, a beaked nose, broad thumbs, and halluces. Mutations in the gene encoding the CREB-binding protein gene (CREBBP, also known as CBP) on chromosome 16p13.3 were identified in 1995. Recently, we developed a mutation analysis protocol using denaturing high-performance liquid chromatography (DHPLC) and identified heterozygous CREBBP mutations in 12 of 21 RTS patients. To test whether exonic deletions represent a common pathogenic mechanism, we assessed the copy number of all the coding exons using a recently developed method, the multiplex PCR/liquid chromatography assay (MP/LC). By using MP/LC, we performed screening for CREBBP exonic deletions among 25 RTS patients in whom no point mutations or small insertions/deletions were identified by DHPLC screening. We identified four classic RTS patients with deletions encompassing multiple exons (14-16, 5-31, 1-16, and 4-26). We conclude that large deletions including several exons are a relatively frequent cause of RTS, and that MP/LC is an effective method for detecting these deletions.
Genetic Testing 02/2006; 10(4):265-71. · 1.17 Impact Factor
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Yoshiyuki Matsumoto,
Ken-Ichi Morishima,
Akira Honda,
Shoji Watabe,
Misa Yamamoto,
Masayuki Hara,
Masaki Hasui,
Chikako Saito,
Toshimitsu Takayanagi,
Tsutomu Yamanaka,
Nakamichi Saito,
Hideaki Kudo,
Nobuhiko Okamoto, Masato Tsukahara,
Shinya Matsuura
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ABSTRACT: Smith-Lemli-Opitz syndrome (SLOS) is an autosomal recessive malformation syndrome characterized by microcephaly, syndactyly of toes, ambiguous genitalia, and mental retardation. The underlying DHCR7 gene has been identified and a wide variety of distinct mutations were reported in USA and European SLOS patients. A significant difference has been suggested in the frequency of SLOS among different ethnic populations. Here, we report mutational analysis of seven Japanese SLOS patients. Five mutations, R352Q, R242H, G303R, X476Q, and S192F, were identified, and R352Q appeared most frequent, since nine out of the 13 mutations of Japanese origin were the same R352Q. These results suggest that R352Q is a predominant founder mutation in Japanese SLOS patients.
Journal of Human Genetics 02/2005; 50(7):353-6. · 2.57 Impact Factor
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Noriko Miyake,
Naohiro Kurotaki,
Hirobumi Sugawara,
Osamu Shimokawa,
Naoki Harada,
Tatsuro Kondoh, Masato Tsukahara,
Satoshi Ishikiriyama,
Tohru Sonoda,
Yoko Miyoshi, [......],
Kenji Kurosawa,
Mayumi Touyama,
Takashi Shiihara,
Nobuhiko Okamoto,
Junji Nishimoto,
Ko-ichiro Yoshiura,
Tohru Ohta,
Tatsuya Kishino,
Norio Niikawa,
Naomichi Matsumoto
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ABSTRACT: Sotos syndrome (SoS) is characterized by pre- and postnatal overgrowth with advanced bone age; a dysmorphic face with macrocephaly and pointed chin; large hands and feet; mental retardation; and possible susceptibility to tumors. It has been shown that the major cause of SoS is haploinsufficiency of the NSD1 gene at 5q35, because the majority of patients had either a common microdeletion including NSD1 or a truncated type of point mutation in NSD1. In the present study, we traced the parental origin of the microdeletions in 26 patients with SoS by the use of 16 microsatellite markers at or flanking the commonly deleted region. Deletions in 18 of the 20 informative cases occurred in the paternally derived chromosome 5, whereas those in the maternally derived chromosome were found in only two cases. Haplotyping analysis of the marker loci revealed that the paternal deletion in five of seven informative cases and the maternal deletion in one case arose through an intrachromosomal rearrangement, and two other cases of the paternal deletion involved an interchromosomal event, suggesting that the common microdeletion observed in SoS did not occur through a uniform mechanism but preferentially arose prezygotically.
The American Journal of Human Genetics 06/2003; 72(5):1331-7. · 10.60 Impact Factor
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Naohiro Kurotaki,
Kiyoshi Imaizumi,
Naoki Harada,
Mitsuo Masuno,
Tatsuro Kondoh,
Toshiro Nagai,
Hirofumi Ohashi,
Kenji Naritomi, Masato Tsukahara,
Yoshio Makita, [......],
Yasuaki Chinen,
Hiro-aki Tomita Ha,
Akira Kinoshita,
Tsuyoshi Mizuguchi,
Koh-ichiro Yoshiura Ki,
Tohru Ohta,
Tatsuya Kishino,
Yoshimitsu Fukushima,
Norio Niikawa,
Naomichi Matsumoto
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ABSTRACT: We isolated NSD1 from the 5q35 breakpoint in an individual with Sotos syndrome harboring a chromosomal translocation. We identified 1 nonsense, 3 frameshift and 20 submicroscopic deletion mutations of NSD1 among 42 individuals with sporadic cases of Sotos syndrome. The results indicate that haploinsufficiency of NSD1 is the major cause of Sotos syndrome.
Nature Genetics 05/2002; 30(4):365-6. · 35.53 Impact Factor
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Shiro Ikegawa,
Hirofumi Ohashi,
Tsutomu Ogata,
Akira Honda, Masato Tsukahara,
Toshihide Kubo,
Mamori Kimizuka,
Masanori Shimode,
Tomonobu Hasegawa,
Gen Nishimura,
Yusuke Nakamura
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ABSTRACT: Chondrodysplasia punctata (CDP) is a heterogeneous group of skeletal dysplasias characterized by stippled epiphyses. A subtype of CDP, X-linked dominant chondrodysplasia punctata (CDPX2), known also as Conradi-Hünermann-Happle syndrome, is a rare skeletal dysplasia characterized by short stature, craniofacial defects, cataracts, ichthyosis, coarse hair, and alopecia. The cause of CDPX2 was unknown until recent identification of mutations in the gene encoding Δ8,Δ7 sterol isomerase emopamil-binding protein (EBP). Twelve different EBP mutations have been reported in 14 patients with CDPX2 or unclassified CDP, but with no evidence of correlation between phenotype and nature of the mutation. To characterize additional mutations and investigate possible phenotype-genotype correlation, we sequenced the entire EBP gene in 8 Japanese individuals with CDP; 5 of them presented with a CDPX2 phenotypes. We found EBP mutations in all 5 CDPX2 individuals, but none in non-CDPX2 individuals. Three of these CDPX2 individuals carried novel nonsense mutations in EBPand the other two, separate missense mutations that had been reported also in different ethnic groups. Our results, combined with previous information, suggest all EBP mutations that produce truncated proteins result in typical CDPX2, whereas the phenotypes resulted from missense mutations are not always typical for CDPX2. Patients with nonsense mutations showed abnormal sterol profiles consistent with a defect in Δ8,Δ7 sterol isomerase. X-inactivation patterns of the patients showed no skewing, an observation that supports the assumption that inactivation of the EBP gene occurs at random in affected individuals. Am. J. Med. Genet. 94:300–305, 2000. © 2000 Wiley-Liss, Inc.
American Journal of Medical Genetics 10/2000; 94(4):300 - 305.
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Masato Tsukahara,
Nobuhiko Okamoto,
Hirofumi Ohashi,
Katsuko Kuwajima,
Ikuko Kondo,
Hideo Sugie,
Toshiro Nagai,
Kenji Naritomi,
Tomoko Hasegawa,
Yoshimitsu Fukushima,
Mitsuo Masuno,
Yoshikazu Kuroki
American Journal of Medical Genetics 12/1998; 75(4):441 - 442.
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ABSTRACT: The parental origin of an extra chromosome in five patients with trisomy 18 was traced using a restriction fragment length polymorphism (RFLP) of the human prealbumin (PA) gene, localized to 18p11.1–q12.1, as a genetic marker. MspI digests of the genomic DNAs of the five patients, their parents and normal controls were hybridized with the PAcDNA. Densitometric analysis on the gene dose of the polymorphic fragments of these patients revealed that three had originated from a maternal meiotic error. The other two patients were uninformative for the parental origin of trisomy 18. Our results indicate that nondisjunctional errors leading to trisomy 18 may occur predominantly at the maternal meiosis, consistent with the results of previous studies on the parental origin of trisomies 21 and 13.
Human Genetics 01/1988; 79(4):377-378. · 5.07 Impact Factor
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