PubMed Health⌕ Search

Biomedical subjects

Gen Nishimura

Publications and source records attributed to Gen Nishimura.

At least 55 records · Page 3Linked to original sources

RMRP mutations in Japanese patients with cartilage-hair hypoplasia.

We examined 12 Japanese patients with metaphyseal chondrodysplasia (MCD) for mutations in the ribonuclease mitochondrial RNA processing gene (RMRP), and identified four novel mutations in two patients with typical and atypical cartilage-hair hypoplasia (CHH), a form of MCD characterized by extra-skeletal manifestations including hypoplastic hair and defective immunity. A patient with typical CHH had a 17-bp duplication at +3 and a de novo 182G > A. The other patient with atypical CHH had a 17-bp insertion at -20 and a 218A > G. Expression analysis revealed that the allele with this insertion mutation in the promoter region silenced the gene. Spectrum analysis of the mutations and polymorphisms in RMRP showed marked difference between the Japanese and other ethnic groups. Such ethnic and phenotypic difference should be taken into account in mutation analysis of the gene.

Adolescent↗

Spondyloepiphyseal dysplasia Maroteaux type: report of three patients from two families and exclusion of type II collagen defects.

Spondyloepiphyseal dysplasia (SED) Maroteaux type is an autosomal dominant skeletal dysplasia, characterized by spondylar dysplasia, mild epiphyseal dysplasia of the large joints, and type E-like brachydactyly. These manifestations overlap with those of spondyloperipheral dysplasia (SPD), in which a sporadic case with a mutation of COL2A1 has been reported. We report on three patients (an affected woman and her son and a sporadic case of an affected man) with SED Maroteaux type. The affected adults were severely short along with stubby hands and feet, and one developed myelopathy as a result of thoracolumbar gibbus. The affected child was mildly short at birth, and developed brachydactyly in early childhood. The radiological hallmarks of these patients included severe platyspondyly with square-shaped vertebral bodies, iliac hypoplasia, epiphyseal hypoplasia of the large joints, and strikingly short metacarpals and phalanges. These radiological findings appeared already apparent in early childhood. SED Maroteaux type was radiologically discriminative from SPD. Brachydactyly was much severe in the former than in the latter, and spondylar dysplasia manifestation was different between both disorders. Mutation screen by polymerase chain reaction-direct sequencing for all exons and their flanking regions of COL2A1 did not reveal any mutations in the three patients.

Adult↗

Spondyloepimetaphyseal dysplasia with joint laxity leptodactylic form: clinical course and phenotypic variations in four patients.

We describe a 5-year-old boy and a 33-year-old woman with spondyloepimetaphyseal dysplasia with joint laxity leptodactylic form (spondyloepimetaphyseal dysplasia with multiple dislocations) (MIM 6003546), and two 12-year-old girls with the disorder who were previously reported as examples of a variant of sponatrime dysplasia. Their clinical manifestations included midface hypoplasia, micromelic short stature, and generalized joint laxity that caused multiple joint problems, including thoracolumbar scoliosis, hip subluxation, progressive genu valgum with knee and patellar subluxation, elbow subluxation, and malalignment of the wrist. Laryngotracheomalacia was present in two individuals, and myopathy was noted in one. The radiological findings in the four individuals included mild platyspondyly most conspicuous in infancy, narrow interpediculate distances of the lumbar spine evident in infancy, retarded epiphyseal ossification that evolved to epiphyseal dysplasia and later to degenerative joint disease, metaphyseal irregularities and striations present in early childhood, and leptodactylic appearance (slender short tubular bones) of the hand.

Adult↗

Ischiospinal dysostosis with cystic kidney disease: report of two cases.

Ischiospinal dysostosis (ISD) is a recently described entity characterized by ischial hypoplasia and spinal segmental anomalies. Nephroblastomatosis that may manifest radiologically as 'polycystic kidney disease' has been regarded as a syndromic constituent of ISD. We report two children with ISD associated with 'renal cystic disease'. One child had multiple renal cysts resembling radiologically adult polycystic kidney disease, leading to renal dysfunction, whereas the other a solitary renal cyst with normal renal function. Renal malformations in ISD may be variable, ranging from diffuse nephroblastomatosis to a solitary renal cyst.

Child, Preschool↗

Two kinds of sex ratio distorters in a moth, Ostrinia scapulalis.

We surveyed female-biased sex ratio traits (SR traits) in a moth, Ostrinia scapulalis (Lepidoptera: Crambidae) from six geographic locations in Japan. A small proportion (8.3%) of females showed the SR trait. About half of them were associated with a Wolbachia infection (SRw+), whereas the remaining ones were not (SRw-). No significant differences in frequencies were detected among locations and years for either SRw+ or SRw- females. In SRw+ matrilines, the SR trait was inherited. Curing the Wolbachia infection by tetracycline at the larval stages resulted in all-male broods in the next generation. These characteristics were identical to the Wolbachia-induced SR trait observed previously in the related species Ostrinia furnacalis. The Wolbachia strain in O. scapulalis was indistinguishable from that in O. furnacalis in terms of the wsp and ftsZ gene sequences, suggesting either that infection originated from a common ancestor of the two hosts or that Wolbachia was transmitted horizontally between the host species. In SRw- matrilines, on the other hand, the SR trait was not due to bacterial infection but some other maternally inherited element, since antibiotic treatment had no effect and bacterial PCR did not give the characteristic product. In these matrilines, the SR trait occasionally failed to show, suggesting the presence of nuclear factor(s) suppressing the SR trait.

Animals↗

Autopsy case of microcephalic osteodysplastic primordial "dwarfism" type II.

Microcephalic osteodysplastic primordial "dwarfism" (MOPD) is a group of disorders similar to Seckel syndrome. Three subtypes (types I-III) have been reported. We report here the first autopsy case of MOPD type II. The patient was a Japanese girl with typical clinical and radiological manifestations of MOPD type II. The manifestations included severe intrauterine and postnatal growth failure, microcephaly, a distinctive facial appearance, micromelia, brachytelephalangy, coxa vara, and V-shaped metaphyses of the distal femora. Other than small cerebral hemispheres, no neuropathological abnormalities were found. Chondro-osseous histology showed thinning of the growth plate, ballooned chondrocytes, reduced cellularity, lack of zonal and columnar formations, and poor formation of primary trabeculae. These findings suggest that impairment of chondrocytic formation and differentiation is the major pathogenesis of MOPD type II.

Abnormalities, Multiple↗

Novel types of COMP mutations and genotype-phenotype association in pseudoachondroplasia and multiple epiphyseal dysplasia.

Mutations in the gene encoding cartilage oligomeric matrix protein ( COMP) cause two skeletal dysplasias, pseudoachondroplasia (PSACH) and multiple epiphyseal dysplasia (MED). More than 40 mutations have been identified; however, genotype-phenotype relationships are not well delineated. Further, mutations other than in-frame insertion/deletions and substitutions have not been found, and currently known mutations are clustered within relatively small regions. Here we report the identification of nine novel and three recurrent COMP mutations in PSACH and MED patients. These include two novel types of mutations; the first, a gross deletion spanning an exon-intron junction, causes an exon deletion. The second, a frameshift mutation that results in a truncation of the C-terminal domain, is the first known truncating mutation in the COMP gene. The remaining mutations, other than a novel exon 18 mutation, affected highly conserved aspartate or cysteine residues in the calmodulin-like repeat (CLR) region. Genotype-phenotype analysis revealed a correlation between the position and type of mutations and the severity of short stature. Mutations in the seventh CLR produced more severe short stature compared with mutations elsewhere in the CLRs ( P=0.0003) and elsewhere in the COMP gene ( P=0.0007). Patients carrying mutations within the five-aspartates repeat (aa 469-473) in the seventh CLR were extremely short (below -6 SD). Patients with deletion mutations were significantly shorter than those with substitution mutations ( P=0.0024). These findings expand the mutation spectrum of the COMP gene and highlight genotype-phenotype relationships, facilitating improved genetic diagnosis and analysis of COMP function in humans.

Achondroplasia↗

Skewed X-chromosome inactivation causes intra-familial phenotypic variation of an EBP mutation in a family with X-linked dominant chondrodysplasia punctata.

X-linked dominant chondrodysplasia punctata (CDPX2) is a skeletal dysplasia characterized by stippled epiphyses, cataracts, alopecia and skin lesions, including ichthyosis. CDPX2 exhibits a number of perplexing clinical features, such as intra- and inter-familial variation, anticipation, incomplete penetrance and possible gonadal and somatic mosaicism. Recently, mutations in the gene encoding Delta8,Delta7 sterol isomerase/emopamil-binding protein (EBP) have been identified in CDPX2. To better understand the genetics of CDPX2, we examined the entire EBP gene by direct sequencing in four CDPX2 patients. We found EBP mutations in all four patients, including three novel mutations: IVS3+1G>A, Y165C and W82C. Surprisingly, a known mutation (R147H) was identified in a patient and her clinically unaffected mother. Expression analysis revealed the mutant allele was predominantly expressed in the patient, while both alleles were expressed in the mother. Methylation analysis revealed that the wild-type allele was predominantly inactivated in the patient, while the mutated allele was predominantly inactivated in her mother. Thus, differences in expression of the mutated allele caused by skewed X-chromosome inactivation produced the diverse phenotypes within the family. Our findings could explain some of the perplexing features of CDPX2. The possibility that an apparently normal parent is a carrier should be considered when examining seemingly sporadic cases and providing genetic counseling to CDPX2 families.

Alleles↗

Autosomal dominant precocious osteoarthropathy due to a mutation of the cartilage oligomeric matrix protein (COMP) gene: further expansion of the phenotypic variations of COMP defects.

We report on a Japanese family of four generations with an autosomal dominant precocious osteoarthropathy. The cardinal clinical manifestations of affected individuals were painful weight-bearing large joints, which started in late childhood or adolescence. The radiological hallmarks included coxa plana, mild epiphyseal dysplasia of the knee, and round talar domes with tibiotalar slant in childhood, which evolved into degenerative joint diseases in adulthood. The disease phenotype was cosegregated with a mutation of the cartilage oligomeric matrix protein (COMP) gene in the family members, who underwent molecular evaluation. COMP mutations have been reported in a mild form of multiple epiphyseal dysplasia (MED), Ribbing type, as well as allied disorders with more severe manifestations, such as MED Fairbank type and pseudoachondroplasia. Unlike previously reported cases with the Ribbing type, the present patients did not have short stature or brachydactyly. This report expands further the phenotypic variations of COMP defects.

Adolescent↗

Paternal UPD14 is responsible for a distinctive malformation complex.

We present a boy and two girls with paternal uniparental disomy of chromosome 14q (patUPD14). One girl had a Robertsonian translocation, whereas two a normal karyotype. Based on the manifestations of these patients and four previously reported patients who all had translocated chromosome 14, The patUPD14 was thought to constitute a distinctive syndrome. The hallmarks included abdominal muscular defects, skeletal anomalies, and characteristic facies. The phenotype of patUPD14 was consistent with that of a previously reported mouse model, i.e., mouse embryos with paternal uniparental disomy of chromosome 12 that has a region orthologous to that of human chromosome 14. Dose effects of newly recognized imprinted genes on human chromosome 14q32, DLK1 and GTL2, could play an important role in the pathogenic mechanism of the distinctive malformation complex.

Abnormalities, Multiple↗

Prenatal diagnosis of hypochondrogenesis using fetal MRI: a case report.

We describe the successful prenatal diagnosis of hypochondrogenesis by MRI. Fetal MR findings were the presence of a conspicuous cartilaginous structure in the basioccipital region, ill-defined ossification of the cervical vertebral bodies, hypoplastic thorax, retarded ossification of the pubic bones, and broad, short long bones. In contrast, fetal US revealed only the presence of short long bones. MRI accurately delineated the axial skeleton in this case and is an effective clinical tool for diagnosing skeletal dysplasias in utero.

Cervical Vertebrae↗

Camurati-Engelmann disease type II: progressive diaphyseal dysplasia with striations of the bones.

We recently found mutations of the transforming growth factor beta 1 (TGF-beta1) gene (TGFB1) in 9 families, in which progressive diaphyseal dysplasia (Camurati-Engelmann disease) is segregating [Kinoshita et al., 2000: Nat Genetics 26:19-20]. During the study, we encountered two unrelated girls, aged 17 and 11 years, who had clinical manifestations of the disorder, such as marfanoid habitus, waddling gait, muscular weakness, intense leg pain, flexion contracture of the hip and knee joints, delayed sexual development, increased serum alkaline phosphatase levels, and increased erythrocyte sedimentation rates. Radiographic studies in the two girls demonstrated not only diaphyseal dysplasia (cortical thickening of the diaphyses) resembling that of progressive diaphyseal dysplasia but also metaphyseal expansion of the long bones, coarse and thick trabeculae of the long and short tubular bones, striations in the spinal, pelvic, and long bones, and cranial sclerosis restricted to the petromastoid regions. These radiographic changes were overall identical with those seen in hyperostosis generalisata with striations of the bones rather than those in progressive diaphyseal dysplasia. Polymerase chain reaction-direct sequencing of all exons and their flanking regions of TGFB1 did not detect any mutations. PCR-single strand conformational polymorphism analysis of the TGF-beta type 1 receptor gene (TGFBR1) did not demonstrate any aberrant DNA fragments. We concluded from these findings that the two girls we described belong to a unique entity distinct from either of the two disorders.

Activin Receptors, Type I↗

Prenatal diagnosis of atelosteogenesis type I at 21 weeks' gestation.

We describe prenatal diagnosis in a male fetus at 21 weeks of gestation with atelosteogenesis type I (AO I). Fetal ultrasonography (US) revealed absent or deficient ossification of the posterior neural arches of the thoracic spine, humeri, radii, ulnae, fibulae, and short tubular bones other than the distal phalanges, in addition to extremely short, thick femora. Fetal magnetic resonance imaging (MRI) using an ultrafast imaging sequence depicted dysmorphic features, pulmonary hypoplasia, and large cisterna magna. Postmortem radiographs warranted a diagnosis of AO I. Autopsy corroborated not only pulmonary hypoplasia but also laryngeal stenosis. The chondro-osseous histological findings were consistent with those of AO I. Meticulous evaluation using fetal US and MRI permits a definitive prenatal diagnosis of AO I to be made.

Abnormalities, Multiple↗