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Gen Nishimura

Publications and source records attributed to Gen Nishimura.

At least 19 recordsLinked to original sources
PubMed2026

Identification of a novel and a recurrent CDC45 variant in a Chinese family with Meier-Gorlin syndrome 7 and a literature review.

INTRODUCTION: Meier-Gorlin syndrome 7 (MGORS7) is a rare autosomal recessive disorder characterized by primordial dwarfism, craniosynostosis, and patellar aplasia, caused by pathogenic variants of CDC45. Here, we report a Chinese patient presenting with classic hallmarks of MGORS7 alongside atypical clinical features, including hearing and visual impairments. METHODS: Clinical and radiological data were collected. Whole-genome sequencing and Sanger sequencing were performed to identify and validate the causative variants. Their functional effects were investigated using an exon-trapping assay, and a literature review of previously reported MGORS7 cases was conducted. RESULTS: Genetic analysis identified two compound heterozygous CDC45 variants: c.1416C>T (p.H472=) and c.1559+2T>A, which are a recurrent variant in the East Asian population and a novel variant, respectively. Our exon-trapping assay indicated that c.1559+2T>A induced aberrant splicing, generating transcripts predicted to undergo nonsense-mediated mRNA decay. Additionally, growth hormone therapy was initiated in our patient, with a noted improvement in growth parameters in the initial assessment and without immediate complications. The literature review identified a total of 32 CDC45 variants in 29 patients with MGORS7, who showed high heterogeneity in clinical phenotypes. DISCUSSION: Our study further expanded the mutational spectrum of CDC45 and provided a preliminary clinical observation suggesting that growth hormone therapy may be beneficial for growth retardation in patients with MGORS7.

CDC45↗
PubMed2007

COL2A1-related skeletal dysplasias with predominant metaphyseal involvement.

Skeletal dysplasias induced by mutations in the collagen 2 gene (the so-called "type 2 collagenopathies") form a wide spectrum in severity and are distinguished by subtle clinical and radiographic differential signs. The unifying features are predominant involvement of the vertebral bodies and the epiphyses of the long bones ("spondylo-epiphyseal" pattern). A mild degree of metaphyseal dysplasia can be seen in the so-called Strudwick variant of spondyloepimetaphyseal dysplasia and is generally mild or absent in other forms. We report here on four individuals with COL2A1 mutations associated with marked metaphyseal involvement with only mild epiphyseal and spondylar changes. One patient who carried a Gly283Arg substitution had a pattern of metaphyseal dysplasia that corresponded precisely to what was termed "Murdoch type metaphyseal dysplasia" in 1960s and was renamed Strudwick type SEMD in 1980s; the second patient carried a Gly181Arg substitution and had severe metaphyseal dysplasia with fractures at the metaphyses reminiscent of the "corner fractures" or Sutcliffe type spondylometaphyseal dysplasia. The third patient also had major metaphyseal involvement but more epiphyseal changes than the others in this study and had a Gly922Arg mutation in COL2A1. The final patient had a small in-frame deletion and unusually ballooned and distorted metaphyses. While it remains true that most individuals with COL2A1 mutations have chondrodysplasia with a spondylo-epiphyseal pattern, metaphyseal involvement is not incompatible with a COL2A1 dysplasia and mutation analysis can be indicated. The observation of these individuals with metaphyseal dysplasia indicates that the phenotypic spectrum associated with mutations in type 2 collagen, the main cartilage protein, is even wider than hitherto assumed.

Adolescent↗
PubMed2006

Identification of novel RMRP mutations and specific founder haplotypes in Japanese patients with cartilage-hair hypoplasia.

Cartilage-hair hypoplasia (CHH), or metaphyseal dysplasia, McKusick type, is an autosomal recessive disease with diverse clinical manifestations. CHH is caused by mutations in RMRP (ribonuclease mitochondrial RNA processing), the gene encoding the RNA component of the ribonucleoprotein complex RNase MRP. A common founder mutation, 70A>G has been reported in the Finnish and Amish populations. We screened 11 Japanese patients with CHH for RMRP mutations and identified mutations in five probands, including three novel mutations (16-bp dup at +1, 168G>A, and 217C>T). All patients were compound heterozygotes for an insertion or duplication in the promoter or 5'-transcribed regions and a point mutation in the transcribed region. Two recurrent mutations were unique to the Japanese population: a 17-bp duplication at +3 and 218A>G. Haplotype analysis revealed that the two mutations common in Japanese individuals were contained within distinct haplotypes. Through this analysis, we have identified a unique mutation spectrum and founder mutations in the Japanese population.

Adolescent↗
PubMed2006

Comprehensive screening of multiple epiphyseal dysplasia mutations in Japanese population.

Multiple epiphyseal dysplasia (MED) is among the most genetically heterogeneous skeletal dysplasias. Six genes involved in MED, COMP, MATN3, COL9A1, COL9A2, COL9A3, and DTDST have been identified; however, the presence of additional disease genes has been reported, and the detection rate for mutations in known genes accounts for no more than 50% of patients with MED in Western populations. Here, we screened the six known disease genes in 35 consecutive Japanese MED patients. We analyzed the entire coding region of each gene, along with flanking intron-exon junctions, by direct sequencing. A total of 19 mutations were identified in COMP, MATN3, COL9A2, COL9A3, and DTDST. The detection rate for known mutations was higher in this study than in previous reports, and we identified a substantially different spectrum of mutations. Mutations in MATN3 were more prevalent among these Japanese patients, whereas no DTDST mutations were detected. Most of the mutations were localized within specific regions of each gene: COMP mutations were found in the calmodulin-like repeat domains; MATN3 mutations in the von Willebrand factor type A domain; and type IX collagen gene mutations occurred in the third collagenous domains. Based on the integration of clinical and genetic information, we propose an algorithm for detecting mutations in Japanese MED patients. Our study further supports the existence of additional MED gene(s).

Base Sequence↗
PubMed2006

Achondroplasia and enchondromatosis: report of three boys.

We report on three boys suffering from achondroplasia concurrent with enchondromatosis-like metaphyseal changes. Two boys who were examined by molecular analysis harbored a mutation of FGFR3, which occurs in most achondroplastic individuals. Given the prevalence of achondroplasia and enchondromatosis, the metaphyseal changes in these patients are less likely to represent the coincidence of both disorders, but rather to result from a rare consequence of the FGFR3 mutation. Impaired FGFs/FGFR3 signaling pathway in achondroplasia inhibits chondrocytic proliferation, which accounts for most characteristics of achondroplasia. On the other hand, it causes conflicting biological consequences that can suppress or stimulate chondrocytic maturation. In a small subset of achondroplastic individuals, the suppression of chondrocytic maturation may outweigh the stimulation, which leads to cartilaginous overgrowth into the metaphysis, eventually causing the metaphyseal dysplasia found in the present patients.

Achondroplasia↗
PubMed2006

A compound heterozygote harboring novel and recurrent DTDST mutations with intermediate phenotype between atelosteogenesis type II and diastrophic dysplasia.

Diastrophic dysplasia sulfate transporter (DTDST) is a sulfate transporter required for the synthesis of sulfated proteoglycans in the cartilage. Over 30 mutations have been described in the DTDST gene, which result in a continuous clinical spectrum of recessively inherited chondrodysplasias, including, in order of increasing severity, a recessive form of multiple epiphyseal dysplasia (rMED), diastrophic dysplasia (DTD), atelosteogenesis type II (AO-II) and achondrogenesis 1B (ACG-1B). Correlation between disease severity and residual sulfate transport activity has been reported. Here we report a patient with DTDST mutations, whose manifestations fell in a range between AO-II and DTD. The patient was a compound heterozygote for the recurrent c.835C>T (p.R279W) and novel c.1987G>A (p.G663R) mutations. Immunocytochemical analysis in HEK293 cells showed that the p.G663R mutation was localized within the cytoplasm, and not to the cell membrane, suggesting p.G663R is a loss-of-function mutation. Our case supports the previously described correlation between the severity of the phenotype and the putative level of residual transport function.

Abnormalities, Multiple↗
PubMed2006

Metaphyseal dysplasia of Braun-Tinschert type: report of a Japanese girl.

We report on a 7-year-old Japanese girl with metaphyseal dysplasia (MD) of Braun-Tinschert type, a recently recognized, autosomal dominant sclerosing bone dysplasia. All individuals with the disorder from four families in the literature originated from a small town in Bohemia or its vicinity. The occurrence of the disorder in a Japanese girl indicates that it is not restricted to Germans. The radiographic hallmarks of the disorder include metaphyseal undermodeling (Erlenmeyer-flask deformity); osteosclerosis of the chondroosseous junctions, metaphyseal cortices, and epiphyseal margins; and exostosis-like bone excrescences at the metaphyseal-diaphyseal junctions. In the girl we described, the latter two findings were conspicuous at age 4 years, but became less prominent with increasing age. The metaphyseal trabeculae were somewhat coarse. The humeri exhibited varus deformity, and the ulnae and fibulae mild bowing. The mean bone mineral density of the lumbar spine was lower than that of age-matched controls. The patient exhibited premature loss of primary teeth, likely to be a sign of increased periodontal bone resorption. Markers of bone formation and resorption were both increased, an indication of a high rate of bone turnover.

Abnormalities, Multiple↗
PubMed2006

Intrafamilial phenotypic diversity in multiple epiphyseal dysplasia associated with a COL9A2 mutation (EDM2).

We describe a Japanese family with an autosomal dominant multiple epiphyseal dysplasia (MED EDM2) showing significant phenotypic diversity among the five affected members. Genomic analysis for COL9A2 identified an Ex3-1A>G heterozygous mutation, which has been proved to result in skipping of exon 3. The proband was a 9-year-old boy, who presented with ulnar club hands due to severe epiphyseal dysplasia in the distal ulnae. Radiological examination showed multiple epiphyseal dysplasias, predominantly involving the knee and the wrist. The hip appeared almost normal. The malalignment of the wrist was successfully treated with a limb lengthening procedure. The phenotype of the asymptomatic 12-year-old brother was similar to, but milder than, that of the proband. The asymptomatic 39-year-old mother, the 35-year-old uncle, and the 65-year-old grandmother with bilateral painful knees showed radiographically mild and severe osteoarthritis of the knee, respectively, and none of them had wrist deformity.

Base Sequence↗
PubMed2006

Nevo syndrome with an NSD1 deletion: a variant of Sotos syndrome?

A 17-month-old girl with clinical manifestations of Nevo syndrome and NSD1 (nuclear receptor binding SET domain protein 1) deletion is described. Nevo syndrome is a rare overgrowth syndrome showing considerable phenotypic overlap with Sotos syndrome-another, more frequent overgrowth syndrome caused by NSD1 mutations or deletions. About a half of Japanese Sotos syndrome patients carry a 2.2-Mb common deletion encompassing NSD1 and present with frequent brain, cardiovascular, or urinary tract anomalies. The girl we described had the common deletion and showed patent ductus arteriosus, atrial septal defect, vesicoureteral reflux, and bilateral hydronephrosis. It was thus concluded that the clinical manifestations, including the Nevo syndrome phenotype, were caused by the microdeletion.

Chromosome Deletion↗
PubMed2006

Genetic and enzymatic analysis for two Japanese patients with idiopathic infantile arterial calcification.

Idiopathic infantile arterial calcification (IIAC) is a life-threatening disorder in young infants. Cardiovascular symptoms are usually apparent within the first month of life. The symptoms are caused by calcification of large and medium-sized arteries, including the aorta, coronary arteries, and renal arteries. Most of the patients die by 6 months of age because of heart failure. Recently, homozygous or compound heterozygous mutations for the ectonucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1) gene were reported as causative for the disorder. ENPP1 regulates extracellular inorganic pyrophosphate (PPi), a major inhibiter of extracellular matrix calcification. Two Japanese patients with IIAC were studied. One, from first-cousin parents, showed a typical clinical course. The onset in the second patient was late. Both of the patients were clinically compatible for IIAC; arterial calcification was shown, and hypertension was prominent. We sequenced all the exons and exon-intron boundaries of the gene and measured nucleotide pyrophosphohydrolase (NPPH) activity of ENPP1. Homozygous Arg730Stop was detected in the typical IIAC patient. The mutation was a novel nonsense mutation and not detected in 60 healthy controls. His NPPH activity was 4% of normal. On the other hand, the late-onset patient was not shown to have any mutations. NPPH activity in this patient was 70% of normal. We confirmed that ENPP1 was also responsible for the Japanese patient with IIAC. The atypical late-onset phenotype may not be associated with ENPP1 abnormalities. IIAC is considered to be a clinically and genetically heterogeneous disorder.

Arteries↗
PubMed2006

Posterior reversible encephalopathy syndrome in children: its high prevalence and more extensive imaging findings.

BACKGROUND: Posterior reversible encephalopathy syndrome is a distinctive clinicoradiological entity observed in a variety of clinical settings, including pediatric patients. A greater prevalence of this syndrome has been suggested in kidney transplant recipients and patients with kidney disease. Although usually considered benign and reversible, characteristics of this syndrome in pediatric patients remain obscure. The objective of the present study involved disclosing details of imaging findings, as well as the clinical course and prevalence of the syndrome in this field. METHODS: We investigated kidney transplant recipients and pediatric patients with kidney disease in our institution from 1990 to 2004. For these patients, clinical course, imaging findings, blood pressure, concurrent medical illnesses, and administrative condition of calcineurin inhibitors were analyzed. RESULTS: Twenty cases of posterior reversible encephalopathy syndrome were investigated in patients ranging in age from 1.9 to 18.3 years. In most patients, radiological abnormalities extended to the gray matter (17 of 20 patients), frontal and temporal lobes, and even the cerebellum (16 patients). Of 177 kidney transplant recipients (cyclosporine, 127 patients; tacrolimus, 50 patients), 6 patients administered cyclosporine (4.7%) and 4 patients administered tacrolimus (8.0%) developed the syndrome after transplantation. CONCLUSION: Posterior reversible encephalopathy syndrome should be suspected in pediatric kidney transplant recipients and patients with kidney disease if they have a sudden episode of neurological symptoms, even if imaging findings are not restricted to the subcortical white matter of the occipital region.

Adolescent↗
PubMed2006

Cytochrome P450 oxidoreductase deficiency in three patients initially regarded as having 21-hydroxylase deficiency and/or aromatase deficiency: diagnostic value of urine steroid hormone analysis.

In this study, we report on three Japanese patients with cytochrome P450 oxidoreductase (POR) deficiency (PORD). Case one was a 46,XY patient who was found to have mildly increased 17alpha-hydroxyprogesterone (17-OHP) by the neonatal mass screening. There was no maternal virilization during pregnancy, and he had no skeletal or genital abnormality. Thus, he was initially diagnosed as having nonclassical 21-hydroxylase deficiency (21-OHD). Cases two and three were 46,XX patients who were identified because of severely virilized external genitalia and maternal virilization during pregnancy. In case two, the neonatal mass screening was normal, and she had no skeletal abnormality except for mild adduction of bilateral third toes. Thus, she was initially diagnosed as having aromatase deficiency. In case three, the neonatal mass screening showed moderately increased 17-OHP, and no skeletal lesion other than rigid second metacarpophalangeal joints was identified in early infancy. Thus, she was initially suspected as having 21-OHD and/or aromatase deficiency. Subsequently, endocrine studies including urine steroid hormone analysis were performed for the assessment of glucocorticoid treatment in case one and for the virilized genitalia in cases two and three, showing adrenal and/or gonadal dysfunction characteristic of PORD. Thus, molecular analysis of POR was carried out, demonstrating homozygosity for R457H in cases one through three. The results imply that clinical features in PORD can be similar to those in 21-OHD or aromatase deficiency, and that comprehensive assessment of the pregnant course, physical examination, and adrenal and gonadal function studies is essential for the precise diagnosis of PORD.

17-alpha-Hydroxyprogesterone↗
PubMed2005

Ehlers-Danlos syndrome type VIB with characteristic facies, decreased curvatures of the spinal column, and joint contractures in two unrelated girls.

Two unrelated girls, aged 11 and 14 years, with clinical manifestations of Ehlers-Danlos syndrome (EDS) type VIB, characteristic facies, skeletal abnormalities, and other features are described. They had Marfanoid habitus with pectus excavatum; fragile, hyperextensible, and readily bruisable skin with widened, atrophic scars; recurrent hematomas; generalized joint laxity; hypotonia; scoliosis; and mild delay of gross motor development. Lysyl hydroxylase deficiency was ruled out in Patient 1. Parental consanguinity was present in Patient 2. They both had, in early childhood, down-slanting palpebral fissures, drooping lower eyelids, short nose, small mouth, and long philtrum. Facial features that persisted included thick eyebrows, hypertelorism, strabismus, blue sclerae, low-set, and slanted ears, hypoplastic columella, high-arched palate, and thin upper lip. They had tubular stenosis of the phalanges, metacarpals, and metatarsals; decreased physiological curvatures of the spinal column with tall vertebrae; and joint contractures including talipes equinovarus and progressive talipes valgus. Their hearing of high-pitched sounds was impaired. They had constipation and recurrent cystitis with an enlarged bladder. In view of these findings, we propose that these two girls represent a clinically recognizable subgroup of EDS type VIB.

Adolescent↗
PubMed2005

Segmental and full paternal isodisomy for chromosome 14 in three patients: narrowing the critical region and implication for the clinical features.

We report on segmental and full paternal isodisomy for chromosome 14 in three previously unreported Japanese patients. Patient 1 was a 5(6/12)-year-old girl, Patient 2 was a male neonate, and Patient 3 was a -year-old girl. Physical examination at birth showed various somatic features characteristic of paternal uniparental disomy for chromosome 14 (upd(14)pat) such as hairy forehead, protruding philtrum, micrognathia, small thorax, and abdominal wall defects in Patients 1-3, and the constellation of somatic features was persistently observed in Patients 1 and 3. Radiological studies at birth delineated unique bell-shaped thorax with coat-hanger appearance of the ribs in Patients 1-3, but the thoracic deformity ameliorated in Patients 1 and 3 by mid childhood. Chromosome analysis showed a 46,XX karyotype in Patients 1 and 3 and was not performed in Patient 2. Microsatellite analysis indicated full paternal isodisomy for chromosome 14 in Patients 1 and 2 and segmental paternal isodisomy for chromosome 14 distal to D14S981 at 14q23.3 in Patient 3. Methylation specific PCR assay for the differentially methylated region (DMR) of GTL2 at 14q32 yielded positive products with methylated allele specific primers and no products with unmethylated allele specific primers in Patients 1-3. Since clinical phenotype was similar between Patient 3 with segmental upd(14)pat and Patients 1 and 2 with full upd(14)pat, the results are keeping with the 14q32 localized imprinted genes as the critical components of the phenotype observed in upd(14)pat and help narrow the search for additional genes to the approximately 40 Mb region distal to D14S981. Furthermore, it is likely that the characteristic thoracic deformity ameliorates with age.

Child↗
PubMed2005

Microdeletion in the SHOX 3' region associated with skeletal phenotypes of Langer mesomelic dysplasia in a 45,X/46,X,r(X) infant and Leri-Weill dyschondrosteosis in her 46,XX mother: implication for the SHOX enhancer.

It is known that SHOX nullizygosity results in Langer mesomelic dysplasia (LMD) and SHOX haploinsufficiency leads to Leri-Weill dyschondrosteosis (LWDC). Here, we report on a microdeletion in the SHOX 3' region identified in a Japanese infant with LMD-compatible skeletal features and a 45,X[191]/46,X,r(X)(p22.3q24)[9] karyotype and in her mother with LWDC-compatible skeletal features and a normal 46,XX karyotype. Physical and auxological examinations revealed mesomelic appearance, ulnarly deviated hands, and borderline micrognathia in the infant, and relatively short forearms and lower legs in the mother. Radiological studies indicated mesomelia, markedly curved radii, hypoplastic ulnas and fibulas, and metaphyseal splaying in the infant, and borderline to mild curvature of the radii, decreased carpal angles, and high-normal triangularization index in the mother. Cytogenetic and molecular studies showed that the ring X chromosome of the infant was missing SHOX and of paternal origin, whereas the cytogenetically normal X chromosomes of the infant and one of the two X chromosomes of the mother, though they retained SHOX with normal coding sequences, had a microdeletion in the SHOX 3' region. The microdeletion started from a position approximately 200 kb from SHOX coding sequences, and spanned 240-350 kb in physical length involving DXYS233. The results, in conjunction with those reported by Flanagan et al. [2002], suggest that a cis-acting enhancer exists in the SHOX 3' region around DXYS233.

3' Flanking Region↗
PubMed2005

Congenital anomaly of cervical vertebrae is a major complication of Rubinstein-Taybi syndrome.

Rubinstein-Taybi syndrome (RTS; MIM# 180849) is a well-known malformation syndrome, characterized by broad thumbs and halluces, a characteristic facies, short stature, and mental retardation. RTS is accompanied by a variety of morbid complications, particularly of the skeleton. Based on the experience of five RTS patients with malformation of the craniovertebral junction, we draw attention to previously unrecognized life-threatening complications of RTS, including instability of C1-C2, os odontoideum, hypoplasia of the dens, and fusion of the cervical vertebrae. One patient developed severe cervical myelopathy. Malformation of the cervical spine may be a common syndromic constituent of RTS, to which special attention should be paid to prevent its neurologic sequelae.

Adolescent↗