Kenjiro Kosaki

Keio University, Tokyo, Tokyo-to, Japan

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Publications (99)188.95 Total impact

  • Article: Persistent hypertension despite successful dilation of a stenotic renal artery in a boy with neurofibromatosis type 1.
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    ABSTRACT: Hypertension is one of the major complications in neurofibromatosis type 1 (NF1). It is known to be caused by renal artery stenosis or pheochromocytoma. However, more than half of hypertensive patients with NF1 do not have either disorder. We report here on a 13-year-old male with NF1 who had hypertension and a stenosis of the right renal artery associated with elevated renal vein renin on the diseased side. He underwent percutaneous transluminal renal angioplasty. In spite of successful dilation of the artery and normalized renin level, high blood pressure persisted beyond 6 months requiring antihypertensive medication. His wide pulse pressure suggested arterial stiffness due to NF1 vasculopathy. We posit that the cause of hypertension in this patient was considered to be arterial stiffness ascribed to NF1 vasculopathy rather than renal artery stenosis. Increased pulse pressure supports the hypothesis. This marker of arterial stiffness can be assessed non-invasively and should be evaluated routinely in NF1. © 2013 Wiley Periodicals, Inc.
    American Journal of Medical Genetics Part A 04/2013; · 2.39 Impact Factor
  • Article: Concurrent Deletion of BMP4 and OTX2 Genes, Two Master Genes in Ophthalmogenesis.
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    ABSTRACT: BMP4 and OTX2 are master genes in ophthalmogenesis. Mutations of BMP4 and OTX2 often lead to eye defects, including anophthalmia-microphthalmia. A significant degree of variable expressivity has been reported in heterozygous individuals with BMP4 or OTX2 mutation. Interestingly, both BMP4 and OTX2 reside on 14q22, being only 2.8 Mb apart. Previous studies reported that among three patients with 14q22 deletion involving BMP4 and OTX2, all had severe eye defects. The minimal degree of variable expressivity among these individuals who were doubly deleted for BMP4 and OTX2 could be attributed to the combinatorial relationship of the two genes observed in animal models. We herein report a patient with a concurrent deletion of BMP4 and OTX2 who exhibited bilateral microphthalmia, more specifically, anterior segment dysgenesis with microcornea. Evolutionarily conserved physical linkage of Bmp4 and Otx2 loci may suggest an advantage of the proximal alignment of the two genes. Another striking feature in the propositus was the progressive white matter loss observed by serial neuroimaging. A review of twelve previously reported patients with 14q22 microdeletion revealed decreased white matter volume in half of the patients. It remains to be elucidated whether the white matter lesion is age-dependent and progressive. In conclusion, anterior segment defects of the eyes, especially when accompanied by decreased white matter volume on neuroimaging, should raise the clinical suspicion of 14q22 microdeletion.
    European journal of medical genetics 10/2012; · 1.57 Impact Factor
  • Article: Catastrophic Autonomic Crisis With Cardiovascular Collapse in Spinal Muscular Atrophy With Respiratory Distress Type 1.
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    ABSTRACT: Spinal muscular atrophy with respiratory distress type 1 (SMARD1) is a rare motor neuron disease that can result in dysautonomia but is usually only mildly symptomatic. We report a young girl with SMARD1 who had a catastrophic autonomic crisis with resultant permanent brain damage during an interhospital transfer. Although she was only mildly symptomatic prior to the transfer, in retrospect, her baseline autonomic function analysis had sympathetic hyperactivity without a typical circadian rhythm, indicating the presence of severe underlying dysautonomia. Because this underlying dysautonomia seemed markedly aggravated by the psychological stress, careful autonomic evaluation and management are warranted in patients with SMARD1.
    Journal of child neurology 08/2012; · 1.59 Impact Factor
  • Article: Tissue-limited ring chromosome 18 mosaicism as a cause of Pitt-Hopkins syndrome.
    American Journal of Medical Genetics Part A 08/2012; 158A(10):2621-3. · 2.39 Impact Factor
  • Article: Microduplication of Xq24 and Hartsfield syndrome with holoprosencephaly, ectrodactyly, and clefting.
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    ABSTRACT: The combination of holoprosencephaly and ectrodactyly, also known as Hartsfield syndrome, represents a unique genetic entity. An X-linked recessive mode of transmission has been suggested for this condition based on the observation that male patients have preferentially been affected. Thus far, no candidate genes have been suggested on the X chromosome. We report a male patient with a full-blown Hartsfield syndrome phenotype who had microduplication at Xq24 involving four genes. He presented with bilateral ectrodactyly of the hands (both hands had four fingers with a deep gap between the 2nd and 3rd digits), cleft lip and palate, and a depressed nasal bridge. Magnetic resonance imaging of the brain revealed lobar holoprosencephaly. His G-banded karyotype was normal. Array comparative genomic hybridization (CGH) using the Agilent 244K Whole Human Genome CGH array revealed a microduplication at Xq24 of 210 kb. Parental testing revealed that the deletion was derived from the asymptomatic mother. Of the genes on the duplicated interval, the duplications of SLC25A43 and SLC25A5 appeared to be the most likely to explain the patient's phenotype. From a clinical standpoint, it is important to point out that the propositus, who performs relatively well with holoprosencephaly and has a developmental quotient around 70, has survived multiple life-threatening episodes of hypernatremia. Awareness of the risk of hypernatremia is of great importance for the anticipatory management of patients with ectrodactyly and an oral cleft, even in the absence of overt hypotelorism. © 2012 Wiley Periodicals, Inc.
    American Journal of Medical Genetics Part A 08/2012; 158A(10):2537-41. · 2.39 Impact Factor
  • Article: 12q14 microdeletion syndrome and short stature with or without relative macrocephaly.
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    ABSTRACT: Patients with 12q14 microdeletion can present with short stature with or without relative macrocephaly. When associated with relative macrocephaly, the phenotype resembles Silver-Russell syndrome (SRS). Short stature is attributable to haploinsufficiency of HMGA2, but a patient with a deletion at the HMGA2 locus only did not have macrocephaly. Hence, the presence of a separate locus for a relative macrocephaly phenotype was suggested. Herein, we present a girl with a 12q14 microdeletion involving the HMGA2 locus who had short stature but did not have macrocephaly. Inclusion and exclusion mappings based on a quantitative review of the degree of relative macrocephaly and the extent of the deletions in previously reported patients with a 12q14 microdeletion demonstrated a presumptive interval for relative macrocephaly spanning a few megabases. These results confirm that a deletion spanning both HMGA2 and this presumptive interval locus would cause an SRS-like phenotype. © 2012 Wiley Periodicals, Inc.
    American Journal of Medical Genetics Part A 08/2012; 158A(10):2542-4. · 2.39 Impact Factor
  • Article: Congenital corneal staphyloma as a complication of Kabuki syndrome.
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    ABSTRACT: Kabuki syndrome has long been clinically defined based mainly on its characteristic eye features. The recent discovery of MLL2 as a causative gene of Kabuki syndrome has enabled the extreme end of the phenotype to be explored. We herein report on two patients with striking visible congenital staphyloma at birth. A diagnosis of Kabuki syndrome was subsequently made in both patients based on a constellation of characteristic eye features, cardiac abnormalities and severe developmental delay, and finally by the confirmation of MLL2 mutations. In conclusion, congenital corneal staphyloma is a complication of Kabuki syndrome with MLL2 mutations.
    American Journal of Medical Genetics Part A 07/2012; 158A(8):2000-2. · 2.39 Impact Factor
  • Article: Age-dependent change in behavioral feature in Rubinstein-Taybi syndrome.
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    ABSTRACT: Rubinstein-Taybi syndrome (RTS) is characterized by developmental delay, postnatal growth retardation, typical facial appearance, and broad thumbs and big toes. The behavioral phenotype of children with RTS has been described as friendly and having good social contacts; however, a short attention span and hyperactivity are sometimes present. Little attention has been paid to the behavioral aspects of adults with RTS. We conducted an observational study focusing on behavioral problems in adolescents and adults with RTS compared with children with RTS. A total of 63 patients with RTS and their caretakers answered self-administered questionnaires regarding behavioral features including the Child Behavior Checklist (CBCL). High total CBCL scores were observed, and the mean score was beyond the clinical cut-off point. After stratification into two groups according to age, the older group (≥14 years) displayed statistically significant higher scores for Anxious/Depression (P = 0.002) and Aggressive Behavior (P = 0.036) than the younger group (≤13 years). In analyses of single items, statistically significant differences between the younger group and the older group were found for 'Nervous, high-strung, or tense' (31.3% vs 67.7%, P = 0.004) and 'Too fearful or anxious' (37.5% vs 64.5%, P = 0.032). Here, we showed that the specific behavioral phenotypes of RTS change during adolescence, with anxiety, mood instability, and aggressive behavior emerging as patients age. A clear need exists to follow-up patients with RTS to catch the eventual emergence of psychiatric problems with age. If necessary, pharmacological treatment should be considered.
    Congenital Anomalies 06/2012; 52(2):82-6.
  • Article: EEC syndrome-like phenotype in a patient with an IRF6 mutation.
    American Journal of Medical Genetics Part A 04/2012; 158A(5):1219-20. · 2.39 Impact Factor
  • Article: Ophthalmic features of CHARGE syndrome with CHD7 mutations.
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    ABSTRACT: Coloboma and various ocular abnormalities have been described in CHARGE syndrome, although the severity of visual impairment varies from case to case. We conducted a multicenter study to clarify the ophthalmic features of patients with molecularly confirmed CHARGE syndrome. Thirty-eight eyes in 19 patients with CHARGE syndrome and confirmed CHD7 mutations treated at four centers were retrospectively studied. Colobomata affected the posterior segment of 35 eyes in 18 patients. Both retinochoroidal and optic disk colobomata were bilaterally observed in 15 patients and unilaterally observed in 3 patients. The coloboma involved the macula totally or partially in 21 eyes of 13 patients. We confirmed that bilateral large retinochoroidal colobomata represents a typical ophthalmic feature of CHARGE syndrome in patients with confirmed CHD7 mutations; however, even eyes with large colobomata can form maculas. The anatomical severity of the eye defect was graded according to the presence of colobomata, macula defect, and microphthalmos. A comparison of the severity in one eye with that in the other eye revealed a low-to-moderate degree of agreement between the two eyes, reflecting the general facial asymmetry of patients with CHARGE syndrome. The location of protein truncation and the anatomical severity of the eyes were significantly correlated. We suggested that the early diagnosis of retinal morphology and function may be beneficial to patients, since such attention may determine whether treatment for amblyopia, such as optical correction and patching, will be effective in facilitating the visual potential or whether care for poor vision will be needed.
    American Journal of Medical Genetics Part A 03/2012; 158A(3):514-8. · 2.39 Impact Factor
  • Article: Hydrocephalus with Hirschsprung disease: severe end of X-linked hydrocephalus spectrum.
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    ABSTRACT: L1CAM molecule is a cell adhesion molecule in nervous and enteric systems and is responsible for X-linked hydrocephalus (XLH) spectrum, which is a rare condition with severe congenital hydrocephalus, dysgenesis of the corpus callosum, intellectual disability, spasticity, and adducted thumbs. Several cases of XLH accompanied by Hirschsprung disease (HSCR) have been reported in the literature, but whether HSCR results from a gain-of-function mutation in cases with XLH, i.e., a neomorphic mutation, or the severe end of the L1CAM mutation spectrum remains unclear. The present patient was a Japanese boy with severe congenital hydrocephalus with aqueductal stenosis as well as hypoplasia of the corpus callosum. HSCR had been confirmed by a biopsy. A mutation analysis of the L1CAM gene showed a C61T mutation in exon 1, resulting in a truncating nonsense mutation at amino acid position 21 and producing an extremely short protein that was unlikely to interact with other proteins. These findings suggest that XLH-HSCR represents the severe end of the XLH spectrum, rather than a neomorphic mutation. A thorough abdominal investigation to rule out HSCR should be considered in patients with XLH accompanied by severe constipation.
    American Journal of Medical Genetics Part A 02/2012; 158A(4):812-5. · 2.39 Impact Factor
  • Article: Reproductive success in patients with Hallermann-Streiff syndrome.
    American Journal of Medical Genetics Part A 09/2011; 155A(9):2311-3. · 2.39 Impact Factor
  • Article: Branchial arch defects and 19p13.12 microdeletion: defining the critical region into a 0.8 M base interval.
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    ABSTRACT: We present a patient with preauricular tags, preauricular and branchial pits, stenosis of the external auditory canals, mild hearing loss, and mild developmental delay who had a de novo 19p13.12 submicroscopic deletion. The size of the deletion was 760-kb, extending from 15,300,338 to 16,064,271 (hg18; NCBI Build 36.1). Our finding supports the notion that 19p13.12 represents a unique microdeletion syndrome characterized by branchial arch defects and the concept of exclusion mapping indicates that the putative locus for the branchial arch development is included in the 0.8-Mb interval defined by the deletion in the presently reported patient.
    American Journal of Medical Genetics Part A 09/2011; 155A(9):2212-4. · 2.39 Impact Factor
  • Article: Reversible diffuse white matter lesion in Alagille syndrome.
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    ABSTRACT: A boy with genetically confirmed Alagille syndrome was incidentally found to manifest striking diffuse hyperintensity of the white matter on T(2)-weighted cranial magnetic resonance images. He never exhibited signs of hepatic encephalopathy. For his progressive liver failure, he underwent a live-donor liver transplant at age 2 years, which unexpectedly resulted in a near-complete resolution of the diffuse white matter lesion. Reversible white matter lesions attributed to cerebral edema were reported in adult patients with liver cirrhosis, but not in the pediatric population. The diffuse reversible white matter lesion in the present case demonstrated T(2) hyperintensity, coupled with restricted diffusion confirmed by apparent diffusion coefficient, and was suggestive of etiologies such as ischemia or cytotoxic edema rather than vasogenic edema.
    Pediatric Neurology 07/2011; 45(1):54-6. · 1.52 Impact Factor
  • Article: Monozygotic twins of Rubinstein-Taybi syndrome discordant for glaucoma.
    American Journal of Medical Genetics Part A 05/2011; 155A(5):1189-91. · 2.39 Impact Factor
  • Article: Overgrowth of prenatal onset associated with submicroscopic 9q22.3 deletion.
    American Journal of Medical Genetics Part A 03/2011; 155A(4):903-5. · 2.39 Impact Factor
  • Article: Role of rare cases in deciphering the mechanisms of congenital anomalies: CHARGE syndrome research.
    Kenjiro Kosaki
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    ABSTRACT: In this review, our work on CHARGE syndrome will be used to exemplify the role of rare cases in birth defects research. The analysis of 29 cases with mutations of CHD7, the causative gene for CHARGE syndrome, clarified the relative importance of the cardinal features, including facial nerve palsy and facial asymmetry. Concurrently, in situ hybridization using chick embryos studies were performed to delineate the expression pattern of Chd7. The Chd7-positive regions in the chick embryos and the anatomical defects commonly seen in patients with CHARGE syndrome were well correlated: expression in the optic placode corresponded with defects such as coloboma, neural tube with mental retardation, and otic placode with ear abnormalities. The correlation between expression in the branchial arches and nasal placode with the clinical symptoms of CHARGE syndrome, however, became apparent when we encountered two unique CHARGE syndrome patients: one with a DiGeorge syndrome phenotype and the other with a Kallman syndrome phenotype. A unifying hypothesis that could explain both the DiGeorge syndrome phenotype and the Kallman syndrome phenotype in patients with CHARGE syndrome may be that the mutation in CHD7 is likely to exert its effect in the common branch of the two pathways of neural crest cells. As exemplified in CHARGE syndrome research, rare cases play a critical role in deciphering the mechanisms of human development. Close collaboration among animal researchers, epidemiologists and clinicians hopefully will enhance and maximize the scientific value of rare cases.
    Congenital Anomalies 03/2011; 51(1):12-5.
  • Article: Surgical treatment for scoliosis in patients with Shprintzen-Goldberg syndrome.
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    ABSTRACT: Shprintzen-Goldberg syndrome (SGS) is characterized by craniosynostosis and marfanoid habitus. The clinical findings of SGS include neurological, cardiovascular, connective tissue, and skeletal abnormalities. Among these skeletal findings, developmental scoliosis is recognized in half of all patients with SGS. However, no earlier reports have described the surgical treatment of scoliosis associated with SGS. Four patients (2 boys and 2 girls; mean age at the time of surgery, 7.3±4.4 y) with SGS who underwent surgical treatment for progressive scoliosis were reviewed. The radiologic findings, operative findings, and perioperative complications were evaluated. The mean preoperative Cobb angle was 102.8±16.9 degrees. The curve patterns were a double curve in 2 cases and a triple curve in 2 cases. Local kyphosis at the thoracolumbar area was recognized in all the cases with a mean kyphosis angle of 49±16 degrees. Growing rod procedures were performed in 2 patients, and posterior correction and fusion were performed in 2 patients. The mean correction rate was 45% in the patients who underwent the growing rod procedures at the time of growing rod placement and 51% in the patients who underwent posterior correction and fusion. Dislodgement of the proximal anchors occurred in 3 of the 4 patients. One patient developed pseudoarthrosis. Two patients developed deep wound infections, and implant removal was necessary in 1 patient. Surgical treatment for scoliosis in patients with SGS was associated with a high incidence of perioperative and postoperative complications including implant dislodgements and deep wound infections attributable to poor bone quality and a thin body habitus, which are characteristic clinical features of this syndrome. Careful preoperative surgical planning and postoperative care are critical for the surgical treatment of scoliosis associated with SGS, especially in infants requiring multiple surgeries. Level IV.
    Journal of pediatric orthopedics 03/2011; 31(2):186-93. · 1.23 Impact Factor
  • Article: Surgical Treatment for Scoliosis in Patients WithShprintzen-Goldberg Syndrome
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    ABSTRACT: Background: Shprintzen-Goldberg syndrome (SGS) is characterized by craniosynostosis and marfanoid habitus. The clinical findings of SGS include neurological, cardiovascular, connective tissue, and skeletal abnormalities. Among these skeletal findings, developmental scoliosis is recognized in half of all patients with SGS. However, no earlier reports have described the surgical treatment of scoliosis associated with SGS. Methods: Four patients (2 boys and 2 girls; mean age at the time of surgery, 7.3±4.4 y) with SGS who underwent surgical treatment for progressive scoliosis were reviewed. The radiologic findings, operative findings, and perioperative complications were evaluated. Results: The mean preoperative Cobb angle was 102.8±16.9 degrees. The curve patterns were a double curve in 2 cases and a triple curve in 2 cases. Local kyphosis at the thoracolumbar area was recognized in all the cases with a mean kyphosis angle of 49±16 degrees. Growing rod procedures were performed in 2 patients, and posterior correction and fusion were performed in 2 patients. The mean correction rate was 45% in the patients who underwent the growing rod procedures at the time of growing rod placement and 51% in the patients who underwent posterior correction and fusion. Dislodgement of the proximal anchors occurred in 3 of the 4 patients. One patient developed pseudoarthrosis. Two patients developed deep wound infections, and implant removal was necessary in 1 patient. Conclusions: Surgical treatment for scoliosis in patients with SGS was associated with a high incidence of perioperative and postoperative complications including implant dislodgements and deep wound infections attributable to poor bone quality and a thin body habitus, which are characteristic clinical features of this syndrome. Careful preoperative surgical planning and postoperative care are critical for the surgical treatment of scoliosis associated with SGS, especially in infants requiring multiple surgeries. Level of Evidence: Level IV.
    Journal of Pediatric Orthopaedics 02/2011; 31(2):186–193. · 1.16 Impact Factor
  • Article: Ichthyosis follicularis, alopecia, and photophobia syndrome: a case report and a pathological insight into pilosebaceous anomaly.
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    ABSTRACT: Ichthyosis follicularis, alopecia, and photophobia (IFAP) syndrome (OMIM 308205) is an extremely rare X-linked oculocutaneous genetic disorder characterized by follicular keratotic papules, total to subtotal alopecia, and photophobia. Previous reports depicted the histopathological features of affected skin lesions, represented by marked follicular plugging and hypoplastic pilosebaceous structures. However, past studies provided limited pathological information of pilosebaceous unit anomaly. Here, we report a 3-year-old boy's case with this uncommon condition. In this case, scalp biopsy samples were processed by both vertical and transverse sectioning techniques, which enabled a more detailed and quantitative pathological analysis of pilosebaceous structures. In vertical slices, miniaturized anagen hair follicles with characteristic follicular plugs were observed. A transverse section identified abortive sebaceous glands in hair follicles, a finding rarely observed in vertical sections. In addition, a transverse slice demonstrated that the number of total hair follicles was not significantly decreased compared with the average hair follicle density in Asians, suggesting that the pilosebaceous hypoplasia might arise from impaired maturation, not from initiation defect, during hair follicle morphogenesis. This study provides a more comprehensive pathological insight into pilosebaceous anomaly in IFAP syndrome and substantiats the usefulness of the combination of vertical and transverse sectioning approaches in the pathological examination of congenital hypotrichosis, including IFAP syndrome.
    The American Journal of dermatopathology 01/2011; 33(4):403-6. · 1.30 Impact Factor

Institutions

  • 1999–2013
    • Keio University
      • Department of Pediatrics
      Tokyo, Tokyo-to, Japan
  • 2007–2012
    • National Center for Child Health and Development
      Tokyo, Tokyo-to, Japan
  • 2005–2010
    • Tokyo Metropolitan Children's Medical Center
      Tokyo, Tokyo-to, Japan
  • 2009
    • Tokyo Medical and Dental University
      • Division of Maxillofacial and Neck Reconstruction
      Tokyo, Tokyo-to, Japan
  • 2003–2007
    • National Research Institute for Child Health and Development
      Tokyo, Tokyo-to, Japan
  • 2006
    • Taipei Veterans General Hospital
      • Department of Pediatrics
      Taipei, Taipei, Taiwan