Recurrent pneumonia in three patients with MECP2 duplication syndrome with aspiration as the possible cause

INTRODUCTION

Methyl-CpG binding protein 2 gene (MECP2) is located on the X chromosome (Xq28) and is important for nervous and immune system functioning. Patients with MECP2 duplication syndrome (MDS) have recurrent respiratory infections (RRIs). Although RRIs often occur with MDS because some patients with MDS also have hypoimmunoglobulinemia and duplication of the interleukin-1-receptor-associated kinase-1 gene (IRAK1), which is also located on Xq28, the phenotype of IRAK1 duplication in patients with MDS remains unclear.

METHODS

The clinical course of three patients with MDS who underwent laryngotracheal separation (LTS) at two institutions was summarized.

RESULTS

Three patients with MDS were identified to have recurrent pneumonia characteristic of aspiration pneumonia, sometimes requiring artificial ventilation therapy; they had no other bacterial infections. After LTS, they rarely had pneumonia. In MDS, MECP2 expression increased two-fold naturally, while IRAK-1 expression showed no difference compared with a healthy subject.

CONCLUSIONS

Since RRIs in MDS are thought to be caused by aspiration and not susceptibility to infection previously estimated to be major complication, the evaluation of aspiration is recommended for RRIs for better management of MDS.

Demyelinating neuropathy in a 6-year-old girl with autism spectrum disorder

Herein we report the case of a 6-year-old girl with autism spectrum disorder (ASD) and weakness in the distal portion of the right upper limb. Although difficult to perform, nerve conduction studies indicated demyelinating neuropathy. Magnetic resonance imaging (MRI) showed swelling a nd high-intensity signals in the right brachial plexus and cervical spinal roots. The symptoms recovered after a single course of i.v. immunoglobulin. Electrophysiological indices and MRI findings also improved after treatment. This case demonstrates the utility of neuroimaging in addition to electrophysiological assessments for the diagnosis of demyelinating neuropathy, particularly in young patients with ASD.

Clinical and mutational spectrum of Japanese patients with Charcot-Marie-Tooth disease caused by GDAP1 variants

BACKGROUND

Mutations in GDAP1 are responsible for heterogeneous clinical and electrophysiological phenotypes of Charcot-Marie-Tooth disease (CMT), with autosomal dominant or recessive inheritance pattern. The aim of this study is to identify the clinical and mutational spectrum of CMT patients with GDAP1 variants in Japan.

MATERIALS AND METHODS

From April 2007 to October 2014, using three state-of-art technologies, we conducted gene panel sequencing in a cohort of 1,030 patients with inherited peripheral neuropathies (IPNs), and 398 mutation-negative cases were further analyzed with whole-exome sequencing.

RESULTS

We identified GDAP1 variants from 10 patients clinically diagnosed with CMT. The most frequent recessive variant in our cohort (5/10), c.740C>T (p.A247V), was verified to be associated with a founder event. We also detected three novel likely pathogenic variants: c.928C>T (p.R310W) and c.546delA (p.E183Kfs*23) in Case 2 and c.376G>A (p.E126K) in Case 8. Nerve conduction study or sural nerve biopsy of all 10 patients indicated axonal type peripheral neuropathy.

CONCLUSION

We identified GDAP1 variants in approximately 1% of our cohort with IPNs, and established a founder mutation in half of these patients. Our study originally described the mutational spectrum and clinical features of GDAP1-related CMT patients in Japan.

Efficacy and tolerability of levetiracetam for pediatric refractory epilepsy

INTRODUCTION

Levetiracetam has a high tolerability and is effective against various seizure types and epilepsy syndromes. However, no study has specifically evaluated the efficacy of levetiracetam in children with refractory epilepsy based on magnetic resonance imaging (MRI) findings and the presence of intellectual disability (ID).

METHODS

We retrospectively evaluated levetiracetam efficacy and safety in 49 pediatric patients who met the following inclusion criteria: (1) diagnosis of refractory epilepsy with first-line antiepileptic (AED) treatment ⩾2years, (2) younger than 20years old, and (3) received oral levetiracetam treatment for ⩾6months. We assessed the relationships of these outcomes with MRI findings and ID status.

RESULTS

Eighteen (37%) patients achieved a ⩾50% reduction in seizure frequency, and the majority (78%) had no remarkable side effects. Twenty-two (45%) patients had previously been treated with more than seven antiepileptic drugs prior to levetiracetam. Among 18 patients who achieved a ⩾50% reduction in seizure frequency, 13 and 5 had negative and positive MRI findings, and 9 and 9 had and did not have ID, respectively.

CONCLUSIONS

Our findings suggest that even for intractable pediatric cases with symptomatic etiology (i.e., MRI lesion and ID), levetiracetam has favorable efficacy for refractory epilepsy with tolerable adverse effects.

De novo mutations in the autophagy gene WDR45 cause static encephalopathy of childhood with neurodegeneration in adulthood

Static encephalopathy of childhood with neurodegeneration in adulthood (SENDA) is a recently established subtype of neurodegeneration with brain iron accumulation (NBIA). By exome sequencing, we found de novo heterozygous mutations in WDR45 at Xp11.23 in two individuals with SENDA, and three additional WDR45 mutations were identified in three other subjects by Sanger sequencing. Using lymphoblastoid cell lines (LCLs) derived from the subjects, aberrant splicing was confirmed in two, and protein expression was observed to be severely impaired in all five. WDR45 encodes WD-repeat domain 45 (WDR45). WDR45 (also known as WIPI4) is one of the four mammalian homologs of yeast Atg18, which has an important role in autophagy. Lower autophagic activity and accumulation of aberrant early autophagic structures were demonstrated in the LCLs of the affected subjects. These findings provide direct evidence that an autophagy defect is indeed associated with a neurodegenerative disorder in humans.

Serum and cerebrospinal fluid S100B, neuron-specific enolase, and total tau protein in acute encephalopathy with biphasic seizures and late reduced diffusion: a diagnostic validity

BACKGROUND

Acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) is characterized clinically by biphasic seizures and late magnetic resonance imaging abnormalities, such as reduced subcortical diffusion from day 3 onwards, often accompanied with some neurological sequelae. In the early stages of the disease, AESD closely resembles its far more prevalent and relatively benign counterpart, febrile seizure (FS).

METHODS

We measured and compared the serum or cerebrospinal fluid (CSF) levels of S100B, neuron-specific enolase (NSE), and total tau protein in 43 patients with FS and 18 patients with AESD, at any point during the disease. To assess early diagnostic validity, we compared these biomarkers in 43 FS and eight AESD patients, with whom the day 0-2 samples were available. We used the receiver-operator characteristic curve to evaluate the diagnostic values of these markers.

RESULTS

The levels of all biomarkers were significantly higher in AESD than FS patients. When only day 0-2 samples from AESD patients were used, the levels of all the measured biomarkers, except serum NSE, were still significantly higher in patients with AESD than in FS, suggesting that AESD could damage astrocytes, neurons, and axons, even in the early stages of the disease. According to the receiver-operator characteristic curve analyses, CSF S100B (cut-off value, 100 pg/mL) and CSF total tau protein (cut-off value, 100 pg/mL) were better predictors of AESD than other biomarkers.

CONCLUSION

The combination of CSF S100B and CSF total tau protein resulted in a positive predictive value of AESD 83.3%, which could be helpful for early diagnosis, facilitating early therapeutic interventions.