Neuroradiological and neurofunctional examinations for the patients with 22q11.2 deletion

Since neuroradiological features of patients with 22q11.2 deletion syndrome are not well-understood, examinations using functional imaging were performed in this study. Brain magnetic resonance imaging(MRI) and 1H-magnetic resonance spectroscopy(MRS) were performed using a clinical 3-tesla MR imager in 4 patients with 22q11.2 deletion syndrome (2 boys and 2 girls; 2~6 years.) and 20 age- and sex-matched healthy control subjects. Furthermore, interictal 123I- iomazenil (IMZ) single photon emission computed tomography(SPECT) was examined in two of the four patients. Among 4 patients with 22q11.2 deletion syndrome, 2 patients showed polymicrogyria and 1 patient showed agyria. Those patients with brain malformations also showed abnormal brain artery and decreased accumulation of IMZ in 123I-IMZ SPECT. Although all 4 patients showed epileptic discharges in electroencephalogram(EEG), one patient with polymicrogyria had no seizure episode. Decreases in γ-aminobutyric acid(GABA) corresponding to the areas of polymicrogyria and/or epileptic discharges in EEG were shown in all patients except for the patient with agyria. Although consistent evidence was not seen in patients with 22q11.2 deletion syndrome in this study, brain malformations and disturbances of the GABAergic nervous system would be underlying mechanisms of the neurodevelopmental abnormalities in this syndrome

A 16q22.2-q23.1 deletion identified in a male infant with West syndrome

In partial monosomy of the distal part of chromosome 16q, abnormal facial features, intellectual disability (ID), and feeding dysfunction are often reported. However, seizures are not typical and the majority of them were seizure-free. Here we present the case of a 16q22.2-q23.1 interstitial deletion identified in a male patient with severe ID, facial anomalies including forehead protrusions and flat nose bridge, patent ductus arteriosus, bilateral vocal cord atresia treated by tracheotomy, and West syndrome, which were developed 10 months after birth. Although phenobarbital, sodium valproate (VPA), and zonisamide were not effective as monotherapies or combination therapies, the patient's epileptic seizures and electroencephalogram anomalies disappeared following combined therapy with lamotrigine and VPA. Although WW Domain Containing Oxidoreductase (WWOX), which is known as a cause of autosomal recessive epileptic encephalopathy, was included within the 6.8-Mb deleted region which identified by targeted panel sequencing and validated by chromosomal microarray analysis, no pathogenic variants were detected in the other allele of WWOX. Therefore, it is possible that other genes within or outside of the long deleted region or their interactions may cause West syndrome in this patient

Evaluation of the GABAergic nervous system in autistic brain : 123I-iomazenil SPECT study

Purpose: To evaluate the GABAA receptor in the autistic brain, we performed 123I-IMZ SPECT in patients with ASD. We compared 123I-IMZ SPECT abnormalities in patients who showed intellectual disturbance or focal epileptic discharge on EEG to those in patients without such findings. Subjects and methods: The subjects consisted of 24 patients with ASD (mean age, 7.3±3.5years), including 9 with autistic disorder (mean age, 7.0±3.7years) and 15 with Asperger’s disorder (mean age, 7.5±3.2years). We used 10 non-symptomatic partial epilepsy patients (mean age, 7.8±3.6years) without intellectual delay as a control group. For an objective evaluation of the 123I-IMZ SPECT results, we performed an SEE (Stereotactic Extraction Estimation) analysis to describe the decrease in accumulation in each brain lobule numerically. Results In the comparison of the ASD group and the control group, there was a dramatic decrease in the accumulation of 123I-IMZ in the superior and medial frontal cortex. In the group with intellectual impairment and focal epileptic discharge on EEG, the decrease in accumulation in the superior and medial frontal cortex was greater than that in the group without these findings. Conclusion The present results suggest that disturbance of the GABAergic nervous system may contribute to the pathophysiology and aggravation of ASD, since the accumulation of 123I-IMZ was decreased in the superior and medial frontal cortex, which is considered to be associated with inference of the thoughts, feelings, and intentions of others (Theory of Mind)

Multi-delay arterial spin labeling brain magnetic resonance imaging study for pediatric autism

Introduction Arterial spin labeling (ASL) is a non-invasive magnetic resonance imaging (MRI) technique that can measure regional cerebral blood flow (rCBF) without radiation exposure. This study aimed to evaluate rCBF in individuals with autism and their age-matched controls, globally and regionally. Methods We performed ASL MRI (3T, pulsed-continuous ASL, 3 delayed ASL imaging sequences) for 33 patients with autism spectrum disorder (ASD) (average age: 7.3 years, range: 2-14 years). Nineteen children (average age: 8.6 years, range: 3-15 years) without ASD and intellectual delay were included as controls. Patients with morphological abnormalities detected on MRI were excluded. Objective analysis was performed with automatic region of interest analysis of the ASL results. The Mann-Whitney U test was used to compare the rCBF results between the groups. Results Compared to the controls, patients with ASD showed a statistically significant decrease in rCBF, respectively, in the insula [left, rCBF 51.8±9.5 mL/100 g/min (mean±SD) versus 59.9±9.8, p=0.0017; right, 51.2±10.1 versus 57.8±8.8, p=0.0354], superior parietal lobule (left, 44.6±8.4 versus 52.0±7.8, p=0.003), superior temporal gyrus (left, 50.0±8.6 versus 56.9±8.6, p=0.007; right, 49.5±8.4 versus 56.4±7.7, p=0.0058), and inferior frontal gyrus (left, 53.0±9.8 versus 59.3±9.9, p=0.0279), which are associated with the mirror neuron system. Conclusions We concluded that patients with ASD showed a statistically significant decline in CBF in regions associated with the mirror neuron system. The advantages of ASL MRI include low invasiveness (no radiation exposure) and short imaging time (approximately 5 min). Studies with larger sample sizes are required to establish the diagnostic value of ASL MRI for ASD

Molecular diagnosis of an infant with TSC2/PKD1 contiguous gene syndrome

A 1-month-old Japanese infant with cardiac rhabdomyoma was diagnosed with TSC2/PKD1 contiguous gene syndrome by targeted panel sequencing with subsequent quantitative polymerase chain reaction that revealed gross monoallelic deletion, including parts of two genes: exons 19–42 of TSC2 and exons 2–46 of PKD1. Early molecular diagnosis can help to detect bilateral renal cyst formation and multidisciplinary follow-up of this multisystem disease

Clinical Guides for aHUS

Atypical hemolytic uremic syndrome (aHUS) is a rare disease characterized by the triad of microangiopathic hemolytic anemia, thrombocytopenia, and acute kidney injury. In 2013, we developed diagnostic criteria to enable early diagnosis and timely initiation of appropriate treatment for aHUS. Recent clinical and molecular findings have resulted in several proposed classifications and definitions of thrombotic microangiopathy and aHUS. Based on recent advances in this field and the emerging international consensus to exclude secondary TMAs from the definition of aHUS, we have redefined aHUS and proposed diagnostic algorithms, differential diagnosis, and therapeutic strategies for aHUS

MRS Study of ACC in Asperger's Syndrome

Purpose Proton magnetic resonance spectroscopy (1H MRS) is a noninvasive neuroimaging method to quantify biochemical metabolites in vivo and it can serve as a powerful tool to monitor neurobiochemical profiles in the brain. Asperger's syndrome (AS) is a type of autism spectrum disorder, which is characterized by impaired social skills and restrictive, repetitive patterns of interest and activities, while intellectual levels and language skills are relatively preserved. Despite clinical aspects have been well-characterized, neurometabolic profiling in the brain of AS remains to be clear. The present study used proton magnetic resonance spectroscopy (1H MRS) to investigate whether pediatric AS is associated with measurable neurometabolic abnormalities that can contribute new information on the neurobiological underpinnings of the disorder. Methods Study participants consisted of 34 children with AS (2-12 years old; mean age 5.2 (±2.0); 28 boys) and 19 typically developed children (2-11 years old; mean age 5.6 (±2.6); 12 boys) who served as the normal control group. The 1H MRS data were obtained from two regions of interest: the anterior cingulate cortex (ACC) and left cerebellum. Results In the ACC, levels of N-acetylaspartate (NAA), total creatine (tCr), total choline-containing compounds (tCho) and myo-Inositol (mI) were significantly decreased in children with AS compared to controls. On the other hand, no significant group differences in any of the metabolites were found in the left cerebellum. Neither age nor sex accounted for the metabolic findings in the regions. Conclusion The finding of decreased levels of NAA, tCr, tCho, and mI in the ACC but not in left cerebellar voxels in the AS, suggests a lower ACC neuronal density in the present AS cohort compared to controls

Neuroimaging in autism spectrum disorders : 1H-MRS and NIRS study

Using proton magnetic resonance spectroscopy (1H-MRS), we measured chemical metabolites in the left amygdala and the bilateral orbito-frontal cortex (OFC) in children with autism spectrum disorders (ASD). The concentrations of N-acetylaspartate (NAA) in these regions of ASD were significantly decreased compared to those in the control group. In the autistic patients, the NAA concentrations in these regions correlated with their social quotient. These findings suggest the presence of neuronal dysfunction in the amygdala and OFC in ASD. Dysfunction in the amygdala and OFCmay contribute to the pathogenesis of ASD.We performed a near-infrared spectroscopy (NIRS) study to evaluate the mirror neuron system in children with ASD. The concentrations of oxygenated hemoglobin (oxy-Hb) were measured with frontal probes using a 34-channel NIRS machine while the subjects imitated emotional facial expressions. The increments in the concentration of oxy-Hb in the pars opercularis of the inferior frontal gyrus in autistic subjects were significantly lower than those in the controls. However, the concentrations of oxy-Hb in this area were significantly elevated in autistic subjects after they were trained to imitate emotional facial expressions. The results suggest that mirror neurons could be activated by repeated imitation in children with ASD

DNA Methylation Dynamics in Human Induced Pluripotent Stem Cells over Time

Epigenetic reprogramming is a critical event in the generation of induced pluripotent stem cells (iPSCs). Here, we determined the DNA methylation profiles of 22 human iPSC lines derived from five different cell types (human endometrium, placental artery endothelium, amnion, fetal lung fibroblast, and menstrual blood cell) and five human embryonic stem cell (ESC) lines, and we followed the aberrant methylation sites in iPSCs for up to 42 weeks. The iPSCs exhibited distinct epigenetic differences from ESCs, which were caused by aberrant methylation at early passages. Multiple appearances and then disappearances of random aberrant methylation were detected throughout iPSC reprogramming. Continuous passaging of the iPSCs diminished the differences between iPSCs and ESCs, implying that iPSCs lose the characteristics inherited from the parent cells and adapt to very closely resemble ESCs over time. Human iPSCs were gradually reprogrammed through the “convergence” of aberrant hyper-methylation events that continuously appeared in a de novo manner. This iPS reprogramming consisted of stochastic de novo methylation and selection/fixation of methylation in an environment suitable for ESCs. Taken together, random methylation and convergence are driving forces for long-term reprogramming of iPSCs to ESCs