Clinical and genetic aspects of hypophosphatasia in Japanese patients

2013 ◽  
Vol 99 (3) ◽  
pp. 211-215 ◽  
Author(s):  
Takeshi Taketani ◽  
Kazumichi Onigata ◽  
Hironori Kobayashi ◽  
Yuichi Mushimoto ◽  
Seiji Fukuda ◽  
...  
Keyword(s):  
Alkaline Phosphatase ◽  
Respiratory Failure ◽  
Short Stature ◽  
Clinical Features ◽  
Japanese Patients ◽  
Compound Heterozygous ◽  
Homozygous Mutation ◽  
Gradual Improvement ◽  
Clinical Type ◽  
Bone Mineralisation

ObjectiveWe examined the clinical and genetic features of hypophosphatasia (HPP) in Japanese patients. HPP is a rare metabolic bone disorder of bone mineralisation caused by mutations in the liver/bone/kidney alkaline phosphatase (ALPL) gene, which encodes tissue-non-specific alkaline phosphatase isoenzyme. MethodsWe retrospectively investigate the incidence and clinical features of 52 patients with paediatric HPP who were born between 1999 and 2010. Mutations of the ALPL gene were analysed in 31 patients.ResultsThe annual incidence of perinatal lethal HPP (PLH) was estimated to be 2–3/1 000 000 births. The most frequent clinical type was PLH followed by prenatal benign. In addition to bone symptoms, cerebral manifestations were frequently observed including convulsion, mental retardation, deafness and short stature with growth hormone deficiency. Respiratory failure was the most significant predictor of a poor prognosis for PLH. The first and second most frequent mutations in the ALPL gene were c.1559delT and c.T979C (p.F327L), respectively. The c.1559delT homozygous mutation was lethal with respiratory failure. Patients with the p.F327L compound heterozygous mutation had the different non-lethal type with short stature and a gradual improvement in ALP level and bone mineralisation.ConclusionsThe most frequent clinical type was the PLH type with prognosis related to respiratory failure, biochemical/radiological changes and ALPL mutations. Cerebral manifestations frequently occurred. Genotype–phenotype correlations were associated with specific outcomes in the PLH type, whereas different clinical features were associated with the same genotype in the non-lethal type.

scholarly journals Predominant Corticospinal Tract Involvement in a Late Infant with Krabbe Disease

2016 ◽  
Vol 7 ◽  
pp. JCM.S40470 ◽  
Author(s):  
Ayumi Yoshimura ◽  
Tetsuya Kibe ◽  
Kaori Irahara ◽  
Norio Sakai ◽  
Kenji Yokochi
Keyword(s):  
Corticospinal Tract ◽  
Late Onset ◽  
Brain Magnetic Resonance Imaging ◽  
Japanese Patients ◽  
Krabbe Disease ◽  
Compound Heterozygous ◽  
Homozygous Mutation ◽  
Pathophysiological Mechanism ◽  
Spastic Quadriplegia ◽  
Tract Involvement

A case of late-infantile Krabbe disease in a patient who presented with developmental regression and spastic quadriplegia in late infancy is reported. Brain magnetic resonance imaging (MRI) at 11 months of age showed predominant corticospinal tract involvement, which usually appears in adult Krabbe disease. Galactocerebrosidase activity in lymphocytes and skin fibroblasts was very low. Genetic testing revealed compound heterozygous mutations of the galactocerebrosidase ( GALC) gene, c.635_646 delinsCTC and c.1901T>C [p.L618S], both of which are known pathogenic mutations. It has been reported that the c.1901T>C [p.L618S] mutation is associated with the late-onset phenotype and, in a past case, a homozygous mutation at this location showed predominant corticospinal tract involvement on MRI. Although further analysis is needed to identify the pathophysiological mechanism, this combination of mutations is likely to be associated with this unusual MRI finding in late-infantile Krabbe disease. Because these types of mutations are common for Japanese patients, it is possible that there are more undiagnosed and late-diagnosed patients of late-infantile Krabbe disease who display limited lesions on MRI. Pediatricians should be aware that patients with late-infantile Krabbe disease can present with predominant corticospinal tract involvement on MRI.

A Novel Mutation Glyl672→Arg in Type 2A and a Homozygous Mutation in Type 2B von Willebrand Disease

1996 ◽  
Vol 76 (02) ◽  
pp. 253-257 ◽  
Author(s):  
Takeshi Hagiwara ◽  
Hiroshi Inaba ◽  
Shinichi Yoshida ◽  
Keiko Nagaizumi ◽  
Morio Arai ◽  
...  
Keyword(s):  
Missense Mutation ◽  
Novel Mutation ◽  
Point Mutations ◽  
Japanese Patients ◽  
Von Willebrand Disease ◽  
Homozygous Mutation ◽  
Missense Mutations ◽  
Reaction Products ◽  
Type 3 ◽  
Von Willebrand

SummaryGenetic materials from 16 unrelated Japanese patients with von Willebrand disease (vWD) were analyzed for mutations. Exon 28 of the von Willebrand factor (vWF) gene, where point mutations have been found most frequent, was screened by various restriction-enzyme analyses. Six patients were observed to have abnormal restriction patterns. By sequence analyses of the polymerase chain-reaction products, we identified a homozygous R1308C missense mutation in a patient with type 2B vWD; R1597W, R1597Q, G1609R and G1672R missense mutations in five patients with type 2A; and a G1659ter nonsense mutation in a patient with type 3 vWD. The G1672R was a novel missense mutation of the carboxyl-terminal end of the A2 domain. In addition, we detected an A/C polymorphism at nucleotide 4915 with HaeIII. There was no particular linkage disequilibrium of the A/C polymorphism, either with the G/A polymorphism at nucleotide 4391 detected with Hphl or with the C/T at 4891 detected with BstEll.

Clinical Features of Japanese Patients With Anti-α-enolase Antibody–Positive Autoimmune Retinopathy: Novel Subtype of Multiple Drusen

2018 ◽  
Vol 196 ◽  
pp. 181-196 ◽  
Author(s):  
Ryo Ando ◽  
Wataru Saito ◽  
Atsuhiro Kanda ◽  
Satoru Kase ◽  
Kaoru Fujinami ◽  
...  
Keyword(s):  
Clinical Features ◽  
Japanese Patients ◽  
Autoimmune Retinopathy

scholarly journals ABCC6 Gene Analysis in 20 Japanese Patients with Angioid Streaks Revealing Four Frequent and Two Novel Variants and Pseudodominant Inheritance

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Satoshi Katagiri ◽  
Yuya Negishi ◽  
Kei Mizobuchi ◽  
Mitsuyoshi Urashima ◽  
Tadashi Nakano ◽  
...  
Keyword(s):  
Medical Records ◽  
Sanger Sequencing ◽  
Pseudoxanthoma Elasticum ◽  
Japanese Patients ◽  
Compound Heterozygous ◽  
Angioid Streaks ◽  
Dermatological Examination ◽  
Abcc6 Gene ◽  
Novel Variants ◽  
Unknown Significance

Purpose. To report the spectrum of ABCC6 variants in Japanese patients with angioid streaks (AS). Patients and Methods. This was a single-center cohort study. The medical records of 20 patients with AS from 18 unrelated Japanese families were retrospectively reviewed. Screening of the ABCC6 gene (exons 1 to 31) was performed using PCR-based Sanger sequencing. Results. Eight ABCC6 variants were identified as candidate disease-causing variants. These eight variants included five known variants (p.Q378X, p.R419Q, p.V848CfsX83, p.R1114C, and p.R1357W), one previously reported variant (p.N428S) of unknown significance, and two novel variants (c.1939C>T [p.H647Y] and c.3374C>T [p.S1125F]); the three latter variants were determined to be variants of significance. The following four variants were frequently identified: p.V848CfsX83 (14/40 alleles, 35.0%), p.Q378X (7/40 alleles, 17.5%), p.R1357W (6/40 alleles, 15.0%), and p.R419Q (4/40 alleles, 10.0%). The ABCC6 variants were identified in compound heterozygous or homozygous states in 13 of 18 probands. Two families showed a pseudodominant inheritance pattern. Pseudoxanthoma elasticum was seen in 15 of 17 patients (88.2%) who underwent dermatological examination. Conclusions. We identified disease-causing ABCC6 variants that were in homozygous or compound heterozygous states in 13 of 18 families (72.2%). Our results indicated that ABCC6 variants play a significant role in patients with AS in the Japanese population.

scholarly journals Paediatric Hypophosphatasia in Real-Life Clinical Practise.

Doctor Ru ◽  
2020 ◽  
Vol 19 (10) ◽  
pp. 57-60
Author(s):  
A.V. Vitebskaya ◽  
◽  
Chernova E.V. Chernova ◽  
Keyword(s):  
Alkaline Phosphatase ◽  
Clinical Case ◽  
Clinical Signs ◽  
Real Life ◽  
Compound Heterozygous Mutation ◽  
Heterozygous Mutation ◽  
Compound Heterozygous ◽  
Milk Teeth ◽  
Motor Retardation ◽  
Gait Disturbances

Objective of the Paper: to describe a clinical case of paediatric hypophosphatasia (HPP) and identify clinical signs, most characteristic of the paediatric HPP form. Key Points. HPP is an congenital rickets-like disease caused by reduced activity of tissue-nonspecific alkaline phosphatase (ALP). According to the time of manifestation, there are perinatal, infant, paediatric, and adult HPPs. The article describes a clinical case of paediatric HPP in a 3.5-year old boy. HPP was diagnosed due to reduced ALP and characteristic X-ray findings. The diagnosis was confirmed with DNA testing: compound heterozygous mutation in с.571 G>A/с.144_148dup of ALPL was found. Conclusion. Typical findings in paediatric HPP are growth retardation and muscular hypotonia, motor retardation; gait disturbances, myalgia, marked fatigue causing limited period of walking; rachitic deformations, premature loss of milk teeth with unchanged roots, respiratory disturbances, and frequent bronchopulmonary disorders. Keywords: hypophosphatasia, children, alkaline phosphatase.

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