PRUNE1-related disorder: Expanding the clinical spectrum.

Neurodevelopmental disorder with microcephaly, hypotonia, and variable brain anomalies (NMIHBA) (OMIM #617481) is an autosomal recessive disease characterized by progressive microcephaly, plagiocephaly, hypotonia, spastic quadriparesis, global developmental delay, intellectual disability, optic features and abnormal brain magnetic resonance imaging (MRI). NMIHBA was recently reported to be caused by PRUNE1 mutations. Eight mutations have been reported in 13 unrelated families. Here, we report 3 PRUNE1 mutations in 1 Caucasian and 3 Japanese families. One recurrent missense mutation (p.Asp106Asn) was previously reported in Turkish and Italian families, while the other 2 mutations (p.Leu18Serfs*8 and p.Cys180*) are novel. We also show that mutant PRUNE1 mRNA can be subject to nonsense-mediated mRNA decay. The patients presented in this study showed atypical NMIHBA phenotypes with no progressive microcephaly. Furthermore, one Caucasian case had significant macrocephaly; therefore, patients with PRUNE1 mutations can exhibit a broad and heterogeneous spectrum of phenotypes.

Genetic analysis of adult leukoencephalopathy patients using a custom-designed gene panel.

Leukoencephalopathies encompass all clinical syndromes that predominantly affect brain white matter. Genetic diagnosis informs clinical management of these patients, but a large part of the genetic contribution to adult leukoencephalopathy remains unresolved. To examine this genetic contribution, we analyzed genomic DNA from 60 Japanese patients with adult leukoencephalopathy of unknown cause by next generation sequencing using a custom-designed gene panel. We selected 55 leukoencephalopathy-related genes for the gene panel. We identified pathogenic mutations in 8 of the 60 adult leukoencephalopathy patients (13.3%): NOTCH3 mutations were detected in 5 patients, and EIF2B2, CSF1R, and POLR3A mutations were found independently in 1 patient each. These results indicate that cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) caused by NOTCH3 mutations is the most frequent adult leukoencephalopathy in our cohort. Moreover, brain imaging analysis indicates that CADASIL patients who do not present typical phenotypes may be underdiagnosed if not examined genetically.

Detection of copy number variations in epilepsy using exome data.

Epilepsies are common neurological disorders and genetic factors contribute to their pathogenesis. Copy number variations (CNVs) are increasingly recognized as an important etiology of many human diseases including epilepsy. Whole-exome sequencing (WES) is becoming a standard tool for detecting pathogenic mutations and has recently been applied to detecting CNVs. Here, we analyzed 294 families with epilepsy using WES, and focused on 168 families with no causative single nucleotide variants in known epilepsy-associated genes to further validate CNVs using 2 different CNV detection tools using WES data. We confirmed 18 pathogenic CNVs, and 2 deletions and 2 duplications at chr15q11.2 of clinically unknown significance. Of note, we were able to identify small CNVs less than 10 kb in size, which might be difficult to detect by conventional microarray. We revealed 2 cases with pathogenic CNVs that one of the 2 CNV detection tools failed to find, suggesting that using different CNV tools is recommended to increase diagnostic yield. Considering a relatively high discovery rate of CNVs (18 out of 168 families, 10.7%) and successful detection of CNV with <10 kb in size, CNV detection by WES may be able to surrogate, or at least complement, conventional microarray analysis.

Novel biallelic SZT2 mutations in 3 cases of early-onset epileptic encephalopathy.

The seizure threshold 2 (SZT2) gene encodes a large, highly conserved protein that is associated with epileptogenesis. In mice, Szt2 is abundantly expressed in the central nervous system. Recently, biallelic SZT2 mutations were found in 7 patients (from 5 families) presenting with epileptic encephalopathy with dysmorphic features and/or non-syndromic intellectual disabilities. In this study, we identified by whole-exome sequencing compound heterozygous SZT2 mutations in 3 patients with early-onset epileptic encephalopathies. Six novel SZT2 mutations were found, including 3 truncating, 1 splice site and 2 missense mutations. The splice-site mutation resulted in skipping of exon 20 and was associated with a premature stop codon. All individuals presented with seizures, severe developmental delay and intellectual disabilities with high variability. Brain MRIs revealed a characteristic thick and short corpus callosum or a persistent cavum septum pellucidum in each of the 2 cases. Interestingly, in the third case, born to consanguineous parents, had unexpected compound heterozygous missense mutations. She showed microcephaly despite the other case and previous ones presenting with macrocephaly, suggesting that SZT2 mutations might affect head size.

A novel missense mutation affecting the same amino acid as the recurrent PACS1 mutation in Schuurs-Hoeijmakers syndrome.

A novel causative variant (c.608G>A, p.Arg203Gln) in PACS1.

A case of atypical Kabuki syndrome arising from a novel missense variant in HNRNPK.

A novel causative variant (c. 464T>C, p.Leu155Pro) in the heterogeneous nuclear ribonucleoprotein K (HNRNPK) gene.

Different X-linked KDM5C mutations in affected male siblings: is maternal reversion error involved?

Genetic reversion is the phenomenon of spontaneous gene correction by which gene function is partially or completely rescued. However, it is unknown whether this mechanism always correctly repairs mutations, or is prone to error. We investigated a family of three boys with intellectual disability, and among them we identified two different mutations in KDM5C, located at Xp11.22, using whole-exome sequencing. Two affected boys have c.633delG and the other has c.631delC. We also confirmed de novo germline (c.631delC) and low-prevalence somatic (c.633delG) mutations in their mother. The two mutations are present on the same maternal haplotype, suggesting that a postzygotic somatic mutation or a reversion error occurred at an early embryonic stage in the mother, leading to switched KDM5C mutations in the affected siblings. This event is extremely unlikely to arise spontaneously (with an estimated probability of 0.39-7.5 × 10(-28) ), thus a possible reversion error is proposed here to explain this event. This study provides evidence for reversion error as a novel mechanism for the generation of somatic mutations in human diseases.

Homozygous c.14576G>A variant of RNF213 predicts early-onset and severe form of moyamoya disease.

OBJECTIVE: RNF213 was recently reported as a susceptibility gene for moyamoya disease (MMD). Our aim was to clarify the correlation between the RNF213 genotype and MMD phenotype. METHODS: The entire coding region of the RNF213 gene was sequenced in 204 patients with MMD, and corresponding variants were checked in 62 pairs of parents, 13 mothers and 4 fathers of the patients, and 283 normal controls. Clinical information was collected. Genotype-phenotype correlations were statistically analyzed. RESULTS: The c.14576G>A variant was identified in 95.1% of patients with familial MMD, 79.2% of patients with sporadic MMD, and 1.8% of controls, thus confirming its association with MMD, with an odds ratio of 259 and p < 0.001 for either heterozygotes or homozygotes. Homozygous c.14576G>A was observed in 15 patients but not in the controls and unaffected parents. The incidence rate for homozygotes was calculated to be >78%. Homozygotes had a significantly earlier age at onset compared with heterozygotes or wild types (median age at onset 3, 7, and 8 years, respectively). Of homozygotes, 60% were diagnosed with MMD before age 4, and all had infarctions as the first symptom. Infarctions at initial presentation and involvement of posterior cerebral arteries, both known as poor prognostic factors for MMD, were of significantly higher frequency in homozygotes than in heterozygotes and wild types. Variants other than c.14576G>A were not associated with clinical phenotypes. CONCLUSIONS: The homozygous c.14576G>A variant in RNF213 could be a good DNA biomarker for predicting the severe type of MMD, for which early medical/surgical intervention is recommended, and may provide a better monitoring and prevention strategy.

Hepatocyte growth factor incorporated into herpes simplex virus vector accelerates facial nerve regeneration after crush injury.

Hepatocyte growth factor (HGF) promotes regeneration of the central nervous system, but its effects on the peripheral nervous system remain unclear. This study was conducted to elucidate the effect of HGF on regeneration of the murine facial nerve after crush injury. To do so, a replication-defective herpes simplex virus vector that incorporated HGF was prepared (HSV-HGF). The main trunk of the facial nerve was compressed by mosquito hemostats, and HSV-HGF, control vector or medium was then applied to the compressed nerve. We found that mice in the HGF group required significantly fewer days for complete recovery from nerve compression. Furthermore, the amplitude of the evoked buccinator muscle compound action potential increased following HSV-HGF application. HGF expression in and around the compressed nerve was demonstrated by enzyme-linked immunoassay and immunohistochemistry. In addition, HSV-HGF introduction around the damaged nerve significantly accelerated recovery of function of the facial nerve. These data suggest a possible role of HGF in promoting facial nerve regeneration after nerve damage. Furthermore, this viral delivery method may be applied clinically for many types of severe facial palsy during facial nerve decompression surgery.

Boron neutron capture therapy for clear cell sarcoma (CCS): biodistribution study of p-borono-L-phenylalanine in CCS-bearing animal models.

Clear cell sarcoma (CCS) is a rare melanocytic malignant tumor with a poor prognosis. Our previous study demonstrated that in vitro cultured CCS cells have the ability to highly uptake l-BPA and thus boron neutron capture therapy could be a new option for CCS treatment. This paper proved that a remarkably high accumulation of (10)B (45-74 ppm) in tumor was obtained even in a CCS-bearing animal with a well-controlled biodistribution followed by intravenous administration of L-BPA-fructose complex (500 mg BPA/kg).

Disposition of TF-PEG-Liposome-BSH in tumor-bearing mice.

BNCT requires high concentration and selective delivery of (10)B to the tumor cell. To improve the drug delivery in BNCT, we conducted a study by devising TPLB. We administrated three types of boron delivery systems: BSH, PLB and TPLB, to Oral SCC bearing mice. Results confirmed that (10)B concentration is higher in the TPLB group than in the BSH group and that TPLB is significantly effective as boron delivery system.

Boron neutron capture therapy for recurrent oral cancer and metastasis of cervical lymph node.

We treated 6 patients with recurrent oral cancer and metastasis to the cervical lymph nodes after conventional treatments in 5 and non-conventional in 1 using BNCT, and herein report our results. The clinical response in our patients ranged from CR to PD. In 5 cases, spontaneous pain decreased immediately after BNCT. Three of the 6 are alive at the time of writing and we found that BNCT contributed to QOL improvement in all.

Boron neutron capture therapy for papillary cystadenocarcinoma in the upper lip: a case report.

Boron neutron capture therapy (BNCT) is a tumor-selective radiation therapy using alpha and (7)Li particles, which are produced by the reaction of neutron with boron ((10)B), and taken up by the tumor. The authors report their first experience of BNCT on a patient with no history of surgery, chemotherapy or conventional radiotherapy for papillary cystadenocarcinoma in the upper lip.

Cavernous malformation after radiation therapy for astrocytoma in adult patients: report of 2 cases.

Radiation-induced cavernous malformations are rarely reported, and most cases have been children. We describe two adult patients with cavernous malformation after irradiation for astrocytoma. Magnetic resonance (MR) imaging, at their ages of 53 years, showed a cavernous malformation in the irradiated field 26 and 10 years after resection and irradiation, respectively. Cavernous malformations were confirmed by the histopathological examination in the both cases. Radiation-induced cavernous malformations are rare in adult patients with astrocytoma. One reason why we found two such cases was that these patients had been successfully treated for astrocytoma and had long follow-up periods.

Spatiotemporal patterns of movement-related fields in stroke patients.

In this study, brain functions in stroke patients and normal subjects were analyzed by observing neuromagnetic fields during button pressing tasks. The measurements included force measurement, visual stimuli presentation and magnetoencephalography (MEG). A 122-channel whole-head MEG system (Neuromag 122) was used. A total of 18 subjects (11 post-stroke and 7 control subjects) participated in the study; adequate MEG data were obtained from 3 of the patients. Equivalent current dipoles for MRFs were estimated with the following parameters: goodness of fit (> 75%), confidence volume (< 6000 mm3), and the duration of dipole (> 10 msec). In addition to the single dipole analysis, Minimum Current Estimates were applied for source estimation since neural activities for stroke patients were observed at the motor cortex of the contralateral side as well as other areas of the brain. Contralateral motor cortex was activated for the normal subjects at 50 ms prior to the force onset, whereas ipsilateral motor cortex was activated for some stroke patients and patients' dipole moments differed not only in their locations but also in their latencies, ranging from -150 to 50 ms to the force onset. The results were in agreement with the findings by PET and fMRI studies; therefore, it was implied that the compensating motor functions were shifted to neighboring areas of the brain due to the recovering motor function after stroke.

Ex vivo gene transfer of basic fibroblast growth factor improves cardiac function and blood flow in a swine chronic myocardial ischemia model.

We previously reported adenovirus-mediated ex vivo gene transfer of basic fibroblast growth factor (bFGF) as a new treatment for leg ischemia. This time, we tested this method on a swine myocardial ischemia model, seeking the possibility of its application for ischemic heart disease. An ameroid constrictor was placed around the proximal left circumflex branch of pigs to induce myocardial ischemia. Simultaneously, a skin section was harvested and fibroblasts were cultured. Fibroblasts were then infected with adenovirus vector containing a bFGF cDNA with a secretory signal sequence (bFGF group, n=8) or a LacZ cDNA (control group, n=8). At 28 days after constrictor implantation, 2.5 x 10(6) fibroblasts were administered into each of the right and left coronary arteries. The injected fibroblasts accumulated in the myocardium without causing myocardial ischemia. Echocardiography, electromechanical mapping and coronary arteriography were conducted just before and 28 days after fibroblast injection, and regional left ventricular myocardial blood flow was measured 28 days after fibroblast injection. These evaluations revealed that the bFGF group exhibited significant development of collateral vessels and improvement of myocardial contraction in the ischemic area compared with the control group. We believe that this method is a promising treatment strategy for ischemic heart disease.

Boronated dipeptide borotrimethylglycylphenylalanine as a potential boron carrier in boron neutron capture therapy for malignant brain tumors.

Takagaki, M., Ono, K., Masunaga, S-I., Kinashi, Y., Oda, Y., Miyatake, S-I., Hashimoto, N., Powell, W., Sood, A. and Spielvogel, B. F. Boronated Dipeptide Borotrimethylglycylphenylalanine as a Potential Boron Carrier in Boron Neutron Capture Therapy for Malignant Brain Tumors. Radiat. Res. 156, 118-122 (2001).A boronated dipeptide, borotrimethylglycylphenylalanine (BGPA), was synthesized as a possible boron carrier for boron neutron capture therapy (BNCT) for malignant brain tumors. In vitro, at equal concentrations of (10)B in the extracellular medium, BGPA had the same effect in BNCT as p-boronophenylalanine (BPA). Boron analysis was carried out using prompt gamma-ray spectrometry and track-etch autoradiography. The tumor:blood and tumor:normal brain (10)B concentration ratios were 8.9 +/- 2.1 and 3.0 +/- 1.2, respectively, in rats bearing intracranial C6 gliosarcomas using alpha-particle track autoradiography. The IC(50), i.e. the dose capable of inhibiting the growth of C6 gliosarcoma cells by 50% after 3 days of incubation, was 5.9 x 10(-3) M BGPA, which is similar to that of 6.4 x 10(-3) M for BPA. The amide bond of BGPA is free from enzymatic attack, since it is protected from hydrolysis by the presence of a boron atom at the alpha-carbon position of glycine. These results suggest promise for the use of this agent for BNCT of malignant brain tumors. Further preclinical studies of BGPA are warranted, since BGPA has advantages over both BPA and BSH.