Kenji Yokochi

Magnetic Resonance Imaging Children with Spastic Diplegia: Correlation with the Severity of their Motor and Mental Abnormality

Magnetic resonance imaging (MRI) findings for 34 children with spastic diplegia, examined between two and 10 years of age, were analysed. Dilatation of the trigone, atrophy of the peritrigonal white matter and prominent deep cortical sulci were seen. On T2‐weighted images, periventricular high‐intensity areas in the white matter adjacent to the trigones and bodies of the lateral ventricles were seen in many children. These MRI features may reflect the pathological changes of periventricular leukomalacia in children with spastic diplegia. Among the MRI findings, only the amount of white matter correlated with severity of disability: white matter reduction corresponded to the more severe motor disabilities.

Phenotypic Spectrum of COL4A1 Mutations: Porencephaly to Schizencephaly

Recently, COL4A1 mutations have been reported in porencephaly and other cerebral vascular diseases, often associated with ocular, renal, and muscular features. In this study, we aimed to clarify the phenotypic spectrum and incidence of COL4A1 mutations.

Two cases of NADH-coenzyme Q reductase deficiency: Relationship to MELAS syndrome

Muscle biopsy specimens from two patients with MELAS syndrome (mitochondrial myopathy, encephalopathy, lactic acidosis, and strokelike episodes) were studied biochemically. 14CO2 production rates from (1-14C)pyruvate, (U-14C)malate, and (1-14C)2-ketoglutarate were all decreased in intact mitochondria in both patients. Rotenone-sensitive NADH cytochrome c reductase activities were decreased to 8% (patient 1) and 6% (patient 2) of control values; succinate cytochrome c reductase and cytochrome c oxidase values were within normal limits. These results indicate that both patients have a defect of NADH-CoQ reductase of the respiratory chain and that MELAS can be brought about by a defect of NADH-CoQ reductase.

Genotype–phenotype correlations in alternating hemiplegia of childhood

Objective: Clinical severity of alternating hemiplegia of childhood (AHC) is extremely variable. To investigate genotype–phenotype correlations in AHC, we analyzed the clinical information and ATP1A3 mutations in patients with AHC. Methods: Thirty-five Japanese patients who were clinically diagnosed with AHC participated in this study. ATP1A3 mutations were analyzed using Sanger sequencing. Detailed clinical information was collected from family members of patients with AHC and clinicians responsible for their care. Results: Gene analysis revealed 33 patients with de novo heterozygous missense mutations of ATP1A3: Glu815Lys in 12 cases (36%), Asp801Asn in 10 cases (30%), and other missense mutations in 11 cases. Clinical information was compared among the Glu815Lys, Asp801Asn, and other mutation groups. Statistical analysis revealed significant differences in the history of neonatal onset, gross motor level, status epilepticus, and respiratory paralysis in the Glu815Lys group compared with the other groups. In addition, 8 patients who did not receive flunarizine had severe motor deteriorations. Conclusions: The Glu815Lys genotype appears to be associated with the most severe AHC phenotype. Although AHC is not generally seen as a progressive disorder, it should be considered a disorder that deteriorates abruptly or in a stepwise fashion, particularly in patients with the Glu815Lys mutation.

De novo and inherited mutations in COL4A2, encoding the type IV collagen α2 chain cause porencephaly.

Porencephaly is a neurological disorder characterized by fluid-filled cysts or cavities in the brain that often cause hemiplegia. It has been suggested that porencephalic cavities result from focal cerebral degeneration involving hemorrhages. De novo or inherited heterozygous mutations in COL4A1, which encodes the type IV α1 collagen chain that is essential for structural integrity for vascular basement membranes, have been reported in individuals with porencephaly. Most mutations occurred at conserved Gly residues in the Gly-Xaa-Yaa repeats of the triple-helical domain, leading to alterations of the α1α1α2 heterotrimers. Here we report on two individuals with porencephaly caused by a heterozygous missense mutation in COL4A2, which encodes the type IV α2 collagen chain. Mutations c.3455G>A and c.3110G>A, one in each of the individuals, cause Gly residues in the Gly-Xaa-Yaa repeat to be substituted as p.Gly1152Asp and p.Gly1037Glu, respectively, probably resulting in alterations of the α1α1α2 heterotrimers. The c.3455G>A mutation was found in the probands mother, who showed very mild monoparesis of the left upper extremity, and the maternal elder uncle, who had congenital hemiplegia. The maternal grandfather harboring the mutation is asymptomatic. The c.3110G>A mutation occurred de novo. Our study confirmed that abnormalities of the α1α1α2 heterotrimers of type IV collagen cause porencephaly and stresses the importance of screening for COL4A2 as well as for COL4A1.

Neonatal cerebral infarction: Symptoms, CT findings and prognosis

In a retrospective multi-center study, we investigated eighteen infants with unilateral cerebral infarctions confirmed by computed tomography (CT) scans. The initial symptoms were observed in all the patients between 0 and 3 days of age. Convulsions or apneic attacks were the initial symptoms in all but one. Only 4 patients had complicated obstetric histories and none showed polycythemia or electrolyte abnormalities. All of the initial CT scans revealed unilaterally localized hypodense areas. In 10, the initial CT scans were performed within 24 hours after the clinical onset. In 16, the lesions were within the territory of the middle cerebral artery, 9 of which also involved the cortico-spinal tract (CST). In the remaining 2 patients, the lesions were located within the territory of the posterior cerebral artery. None of the 9 patients without CST involvement developed hemiplegia, whereas 5 (56%) of the 9 with CST involvement had hemiplegia, which is a fairly low incidence compared with that in adult cases. This difference was thought to be related to neonatal brain plasticity.

Recurrent cerebral infarctions and del(10)(p14p15.1) de novo in HDR (hypoparathyroidism, sensorineural deafness, renal dysplasia) syndrome

We report on a Japanese boy with HDR syndrome (hypoparathyroidism, sensorineural deafness, renal dysplasia) and recurrent cerebral infarctions in the basal ganglia. The patient experienced cerebral infarctions four times between age 7 months and age 20 months. Chromosome analysis of the patient demonstrated a 46,XY, del(10)(p14p15.1) de novo. This suggests that the putative gene responsible for HDR syndrome is located at 10p14-p15.1.

Paroxysmal ocular downward deviation in neurologically impaired infants

Thirteen neurologically impaired children with paroxysmal ocular downward deviation were studied. The eye movement accompanied downward movement of the upper eyelid; there was no coincident paroxysmal discharge on electroencephalography. The ocular abnormality was observed in infancy, predominantly in preterm infants, and spontaneously resolved in many of them. All patients had spastic quadriplegia or diplegia and mental retardation. Many children also had cortical visual impairment. This eye movement abnormality, not reported previously, should be considered to be a neurologic sign in brain-damaged infants with cortical visual impairment.

Mitochondrial Myopathy, Encephalopathy, Lactic Acidosis and Stroke-like Episodes Syndrome and NADH-CoQ Reductase Deficiency

M. KOBAYASHI 1, H. MORISHITA 1, N. SUGIYAMA 1, K. YOKOCHI 1, M. NAKANO 1, Y. WADA 1, Y. HOTTA 2, A. TERAUCHI 3 and I. NONAKA 4 1Department of Paediatrics and ~First Department of Anatomy, Medical School, Nagoya City University, Kawasumi-cho, Mizuho-ku, Nagoya 467, Japan 3Higashimatsumoto National Sanatorium, Matsumoto 399-65, Nagano, Japan 4National Centre for Nervous, Mental and Muscular Disorders, Kodaira 187, Tokyo, Japan

The Spectrum of ZEB2 Mutations Causing the Mowat-Wilson Syndrome in Japanese Populations

Mowat–Wilson syndrome (MWS) is a multiple congenital anomaly syndrome characterized by moderate or severe intellectual disability, a characteristic facial appearance, microcephaly, epilepsy, agenesis or hypoplasia of the corpus callosum, congenital heart defects, Hirschsprung disease, and urogenital/renal anomalies. It is caused by de novo heterozygous loss of function mutations including nonsense mutations, frameshift mutations, and deletions in ZEB2 at 2q22. ZEB2 encodes the zinc finger E‐box binding homeobox 2 protein consisting of 1,214 amino acids. Herein, we report 13 nonsense and 27 frameshift mutations from 40 newly identified MWS patients in Japan. Although the clinical findings of all the Japanese MWS patients with nonsense and frameshift mutations were quite similar to the previous review reports of MWS caused by nonsense mutations, frameshift mutations and deletions of ZEB2, the frequencies of microcephaly, Hirschsprung disease, and urogenital/renal anomalies were small. Patients harbored mutations spanning the region between the amino acids 55 and 1,204 in wild‐type ZEB2. There was no obvious genotype–phenotype correlation among the patients. A transfection study demonstrated that the cellular level of the longest form of the mutant ZEB2 protein harboring the p.D1204Rfs*29 mutation was remarkably low. The results showed that the 3′‐end frameshift mutation of ZEB2 causes MWS due to ZEB2 instability.