Molecular diagnosis of 405 individuals with autism spectrum disorder

Autism spectrum disorder (ASD) is caused by combined genetic and environmental factors. Genetic heritability in ASD is estimated as 60-90%, and genetic investigations have revealed many monogenic factors. We analyzed 405 patients with ASD using family-based exome sequencing to detect disease-causing single-nucleotide variants (SNVs), small insertions and deletions (indels), and copy number variations (CNVs) for molecular diagnoses. All candidate variants were validated by Sanger sequencing or quantitative polymerase chain reaction and were evaluated using the American College of Medical Genetics and Genomics/Association for Molecular Pathology guidelines for molecular diagnosis. We identified 55 disease-causing SNVs/indels in 53 affected individuals and 13 disease-causing CNVs in 13 affected individuals, achieving a molecular diagnosis in 66 of 405 affected individuals (16.3%). Among the 55 disease-causing SNVs/indels, 51 occurred de novo, 2 were compound heterozygous (in one patient), and 2 were X-linked hemizygous variants inherited from unaffected mothers. The molecular diagnosis rate in females was significantly higher than that in males. We analyzed affected sibling cases of 24 quads and 2 quintets, but only one pair of siblings shared an identical pathogenic variant. Notably, there was a higher molecular diagnostic rate in simplex cases than in multiplex families. Our simulation indicated that the diagnostic yield is increasing by 0.63% (range 0-2.5%) per year. Based on our simple simulation, diagnostic yield is improving over time. Thus, periodical reevaluation of ES data should be strongly encouraged in undiagnosed ASD patients.

Formation and evolution of carbonaceous asteroid Ryugu: Direct evidence from returned samples

Samples of the carbonaceous asteroid Ryugu were brought to Earth by the Hayabusa2 spacecraft. We analyzed 17 Ryugu samples measuring 1 to 8 millimeters. Carbon dioxide-bearing water inclusions are present within a pyrrhotite crystal, indicating that Ryugu's parent asteroid formed in the outer Solar System. The samples contain low abundances of materials that formed at high temperatures, such as chondrules and calcium- and aluminum-rich inclusions. The samples are rich in phyllosilicates and carbonates, which formed through aqueous alteration reactions at low temperature, high pH, and water/rock ratios of <1 (by mass). Less altered fragments contain olivine, pyroxene, amorphous silicates, calcite, and phosphide. Numerical simulations, based on the mineralogical and physical properties of the samples, indicate that Ryugu's parent body formed ~2 million years after the beginning of Solar System formation.

Case Report: Anti-MOG Antibody Seroconversion Accompanied by Dimethyl Fumarate Treatment

Here we report three cases of anti-myelin oligodendrocyte glycoprotein (MOG) antibody–associated disease (MOGAD) mimicking multiple sclerosis in which seropositivity for anti-MOG antibodies occurred during disease-modifying drug dimethyl fumarate (DMF) treatment. These patients developed relapses with anti-MOG antibody seroconversion after switching from fingolimod or steroid pulse therapy to DMF, which was associated with peripheral lymphocyte recovery. MOGAD is considered a humoral immune disease, and DMF reportedly enhances Th2-skewed humoral immune activity. Therefore, we suggest that DMF, but not fingolimod, may exacerbate humoral immune imbalance and enhance autoantibody production, leading to aggravation of MOGAD.

THU0066 DOES PORPHYROMONAS GINGIVALLIS MODULATE GUT MICROBIOME RESULTING IN AGGRAVATION OF DISEASE ACTIVITY IN RHEUMATOID ARTHRITIS?

Background:

Oral Porphyromonas gingivalis (Pg) infection in rheumatoid arthritis (RA) model revealed aggravation of arthritis, dysbiosis and higher serum LPS (1). We reported that IgA/IgG antibody against Pg-LPS ratio among the patients with RA related to disease marker levels and disease activities (2). However, there are still few reports related to Gut-Oral axis.

Objectives:

Firstly, how total intestinal bacteria, well-known 5 species of gut bacteria behave in relation to disease activities and markers. Secondly, how infection by Pg aggravate RA in relation to microflora, disease activities and markers.

Methods:

Eighty-seven RA patients with inadequate response to conventional synthetic DMARDs were evaluated. Age: 68.1±8.7 years, female (%): 79.3, disease duration: 136±91 months, DAS28-ESR: 4.68±0.98. Fecal bacteria numbers of total bacteria, Bifidobacterium, Lactobacillus, E. coli, Bacteroides and Staphylococcus were determined by PCR analysis. Fecal and serum LPS levels were measured by LAL assay. Serum endotoxin neutralizing activity (ENC) was determined along with RA disease activity and markers measurement. Infection of Pg was proofed by IgG and IgA anti-LPS antibody measurement. The statistical relationships between variables were analyzed by Spearman’s non-parametric rank correlation analysis and expressed as Spearman’s rank correlation coefficient “ρ”.

Results:

At first, we could neglect background effects as duration, methotrexate dose for measuring total or each bacterial number (data not shown). As shown in Figure 1, total bacteria only showed positive correlation with IL-6 levels (ρ= 0.230, p = 0.034), however inversely correlated with disease activities such as pVAS (ρ= -0.223, p = 0.038) and Pain VAS (ρ= -0.260, p = 0.015). While no significant relationship was observed between the numbers of each of 5 species of bacteria and the disease activities and makers except Bifidobacterium. In contrast, LPS-related markers showed positive correlation with disease activities and markers. Among LPS-related biomarker values, serum LBP levels mainly correlated with most of RA biomarker-ESR (ρ= 0.497, p <0.0001), CRP (ρ= 0.697, p <0.0001), MMP3 (ρ= 0.546, p <0.0001) and so on. Fecal LPS level was shown significant positive correlation with disease activities, however almost no correlation was observed in serum LPS level. IgA anti-LPS antibody levels to Pg, resulted in inverse correlation with total bacteria (ρ= -0.441, p<0.0001), Lactobacillus (ρ= -0.224, p=0.037), Bacteroides (ρ = -0.200, p = 0.064) and E. coli (ρ= -0.260, p = 0.015), moreover, positive correlation with serum LPS (ρ= 0.284, p = 0.008) and LBP (ρ= 0.247, p = 0.021) and inverse correlation with ENC (ρ = -0.321, p = 0.002) were found. On the other hand, IgG anti-Pg-LPS antibody levels which reflect systemic infection, inversely correlated SDAI (ρ = -0.308, p = 0.004), PainVAS (ρ = -0.433, p < 0.0001), and so on.

Conclusion:

Serum LBP highly associated with RA activity and markers, which suggests bacterial LPS as roles in triggering and perpetuating disease activity in RA. In contrast, IgA anti-Pg-LPS, IgG anti-Pg-LPS antibody reflecting infection of Pg, negatively associated with intestinal total bacteria (ρ=-0.4405, p<0.0001), RA disease activities, respectively. These results may show a possible oral -gut relationship resulting in aggravation of disease activity in RA.

Disclosure of interest:

None declared

References:

[1]Sato K, Takahashi N, Kato T et al. Aggravation of collagen induced arthritis by orally administered Porphyromonas gingivalis through modulation of the gut microbiota and gut immune system. Sci Rep 2017; 7:6955.

[2]Kuniaki Terato, Takaki Waritani, Richio Fukai et al. Contribution of bacterial pathogens to evoking serological disease markers and aggravating disease activity in rheumatoid arthritis. PloS One. 2018;13(2): e0190588.

Disclosure of Interests:

None declared

SAT0146 INHIBITION OF RADIOGRAPHIC PROGRESSION BY IGURATINOD IN 116 JAPANESE RHEUMATOID ARTHIRITIS PATIENTS DESPITE CONVENTIONAL SYNTHETIC DISEASE-MODIFYING ANTIRHEUMATIC DRUGS THERAPY

Background:

Japanese double-blind clinical practice studies of Iguratimod (IGU) for active rheumatoid arthritis (RA) patients indicated an early and sustained efficacy as a new conventional synthetic disease-modyfing anti-rheumatic drugs (csDMARDs) [1] as well as the safety of the treatment[2]. IGU also inhibit activation of NFkB and production of RANKL, indicating strong inhibiting activity against bone destruction. However, studies focused on the inhibitory effects of joint destruction by IGU has been poorly documented in clinical practice (3).

Objectives:

To evaluate inhibitory effect during 1 year by additional IGU therapy in 116 RA patients despite csDMARDs therapy.

Methods:

Inhibitory effects of joint damage were evaluated by modified total Sharp scoring (mTSS) at baseline and 1 year after IGU prescription. RA activity was measured by DAS28-ESR.

Results:

The subjects were 116 cases, 30 male, age 63.2 yrs, disease duration 93.7 months. MTX was used weekly (84 cases, 72.4%), and cs DMARDs were used as BUC 43 cases, SASP 13 cases, TAC 5 cases, and LEF 1 cases. bDMARDs were used even in 8 cases, and steroids were used in 3.9 mg (70 cases, 60.3 %). Complications were observed in 70 cases (60.3%). DAS28-ESR were significantly improved from 4.29 (baseline) to 3.65 (6 months), 3.68 (12 months), respectively (P<0.0001). As shown in Figure 1, joint destruction measured by mTSS was significantly suppressed from 7.74 to 0.57 at 1 year (P<0.0001). 70.6% of patients satisfied structural remission (ΔmTSS≤0.5). Clinically relevant radiographic progression (CRRP)(mTSS>3) was observed in 10 cases (8.6%), and rapid radiographic progression(RRP) (mTSS≥5) was observed in 2 cases (1.6%). Adverse events were observed in 26 cases (22.4 %).

To investigate prognostic factor for CRRP, clinical data in baseline, 6, 12 months between ten patients with CRRP and 82 patients with structural remission were compared. As shown in Table 1, longer disease duration, more SJC (P<0.05), High CRP level(P<0.005) were prognostic for CRRP in IGU treated patients.

Conclusion:

Iguratimod suppressed not only clinical activities but also joint destruction in RA patients resistant to csDMARDs therapy.

Table 1. Prognostic factor for CRRP

References:

[1]Ishiguro N, Yamamoto K, Katayama K et al. Concomitant iguratimod therapy in patients with active rheumatoid arthritis despite stable doses of methotrexate a randomized, double-blind, placebo-controlled trial. Mod Rheumatol. 2013;23(3):430-9

[2]Hara M, Ishiguro N, Katayama K et al. Safety and efficacy of combination therapy of iguratimod with methotrexate for patients with active rheumatoid arthritis with an inadequate response to methotrexate: an open-level extension of a randomized, double-blind, placebo-controlled trial. Mod Rheumatol. 2014;24(3):410–8.

[3]Ishikawa K, Ishikawa J.Iguratimod, a synthetic disease modifying anti-rheumatic drug inhibiting the activation of NF-jB and production of RANKL: Its efficacy, radiographic changes,safety and predictors over two years’ treatment for Japanese rheumatoid arthritis patients. Mod.Rheumatol.2019,29(3), 418–429.

Disclosure of Interests:

None declared

FRI0127 Suppression of radiographic progression after gradual methotrexate tapering in patients with rheumatoid arthritis patients maintaining low disease activity - Prospective multicenter study-

Background:

Many studies have been reported to reduce/discontinue Biologics in the treatment of rheumatoid arthritis (RA). In contrast, study for tapering methotrexate (MTX) has been limited (1,2).

Objectives:

We prospectively examined whether bone destruction will progress at 48 weeks after tapering or discontinuing MTX (UMIN000028875).

Methods:

The subjects were RA patients who have maintained low disease activity or lower for 24 weeks or more in DAS28-CRP after MTX administration. Patients having PDUS Grade 2 or 3 per site by bilateral hand ultrasonography (26 area) were excluded in this study owing to risk for joint destruction. The joint destruction was evaluated by the joint X-ray evaluation by modified total Sharp scoring (mTSS) at 1 year after the start of tapering MTX. Evaluation of clinical disease activities, severe adverse events, the continuation rate during MTX tapering were also evaluated. According to tapering response, prognostic factor for good response for tapering, joint destruction was determined. Predictors for successful tapering MTX and progression of bone destruction were determined. Statistical analysis was performed by t-test or Wilcoxon rank sum test using SAS .13.2 software.

Results:

The subjects were 79 (16 males, 63 females). Age average 60.9 years, disease duration 4 years 4 months, MTX dose 8.43 mg / w, DAS28-CRP 1.52, DMARDs (24.3%), ACPA 192.7 U / ml (70.5%), RF 55.6 IU / ml (65.4%).MTX was tapered from an average of 8.43 mg / w before study to 5.46 mg / w one year later. In the treatment evaluation, DAS28-CRP increased from 1.52 to 1.84. 89.7% of subjects did not progress joint damage. Other disease activities significantly increased (Table 1). The one-year continuation rate was 78.2%. Since tapering effects were varied widely, we divided patients into three groups; Flared group (N=14, initial MTX dose 8.71mg/w, final MTX dose 8.42mg/w), Low response group (N=31, final MTX reduction rate< 50%, initial MTX dose 8.93mg/w, final MTX dose 6.22mg/w), High response group (N=34, final MTX reduction rate≥ 50%, initial MTX dose 8.5mg/w, final MTX dose 3.15mg/w)(Table 2).Higher RF value at baseline and higher MTX dose at 3M, 6M were predictors of whether a subject was in Low response group or High Response group. Higher RF value and mTSS at baseline and higher MTX dose at 6M were predictors whether a subject was in Flared group or High response group. Lower age was predictor of whether a subject was in Flared group or Low responder group. Finally, mean ΔmTSS /y in Flared group (0.36) was not significantly higher than in low response group (0.07) and in high response group (0.01).

Table 1Table 2.

Predictors for successful tapering MTX and progression of bone destruction

Conclusion:

Patients with MTX-administered low disease activity and finger joint echo PDUS grade 1 satisfy almost no joint destruction even after MTX reduction. For tapering, predictors may be helpful for maintaining patient’s satisfaction.

References:

[1]Baker KF, Skelton AJ, Lendrem DW et al. Predicting drug-free remission in rheumatoid arthritis: A prospective interventional cohort study. J. Autoimmunity. 2019;105: 102298.

[2]Lillegraven S, Sundlisater N, Aga A et al. Tapering of Conventional Synthetic Disease Modifying Anti-Rheumatic Drugs in Rheumatoid Arthritis Patients in Sustained Remission: Results from a Randomized Controlled Trial. American College of Rheumatology. 2019; Abstract L08.

Disclosure of Interests:

None declared

AB0298 LONG-TERM SUPPRESSION OF RAPID RADIOGRAPHIC PROGRESSION AFTER DISCONTINUATION/REDUCTION OF SHORT-TERM BIOLOGIC THERAPY IN PATIENTS WITH EARLY DESTRUCTIVE RHEUMATOID ARTHRITIS ACCOMPANIED WITH EXTENSIVE BONE MARROW EDEMA

Background:

We reported that short-term (3 or 6 months) treatment with biologics (BIO) group compared with conventional synthetic non-biological disease-modifying anti rheumatic drug (csDMARDs) enhanced group is more effective in the reducing bone marrow edema (BE) and improving structural remission in early destructive RA accompanied with extensive hand BM despite csDMARDs therapy (1).

Objectives:

Purpose of this extended study is to investigate whether suppression of RRP will maintain after the discontinuation/reduction of short term biological treatment during over 1 year. Clinical registration number; (UMIN-CTR 000013614)(Figure 1)

Methods:

RA disease activity was evaluated by DAS28-ESR after BIO withdrawal/reduction at 12 months. Bone destruction was determined by modified total Sharp scoring (mTSS) using by conventional radiography expressed as yearly progression of mTSS (ΔmTSS/y) at 12 months. Statistical analysis were performed by t-test or Wilcoxon rank sum test using SAS .13.2 software

Results:

Fourteen out of 23 patients in BIO group achieved improvement of BM (>70% improvement of baseline BE). Three patient continued BIO. Among 11 patient started to discontinuation/reduction of BIO, 7 patients were successful for discontinuation of BIO. Four patients flared (Table 1). Mean DAS28-ESR, mean ΔmTSS/y at 0, 12 months after discontinuation in 7 patients were 1.77, 2.02 and -0.66,-0.44, respectively (no significant difference between values in 0 and12 month). In contrast, those in 4 flared patients were 1.91, 4.08 and 0, 1.83, respectively (significant difference). Finally, to resolve baseline prognostic factors for improvement of BE for biological treatment, we compared baseline data between 14 BE improved and 9 BE unimproved RA patients. Low DAS28-ESR at 3 or 6 month (P<0.001) are indicated for significant prognostic factor for improvement of BE, although Low DAS28-ESR at baseline (P=0.07) may associate improvement of BE.

Table 1.

Summary of 1 year clinical data in 11 patients treated in BIO discontinuation/reduction after improvement of BE by short-term treatment of BIO

Conclusion:

Results of this study indicated suppression of RRP will maintain during over 1 year after the discontinuation of short term biological treatment in some patients. We recommend that a short-term treatment with biologics for early RA patients, who are resistant to non-bio DMARDs therapy and at high risk to transit to RRP, will be an effective and economical treatment strategy.

References:

[1]K. Katayama, T. Okubo, S. Sato et al. Prevention of extensive bone marrow edema and consequent rapid radiographic progression by short term usage of biologics in DMARDs resistant patients with early destructive rheumatoid arthritis. EULAR meeting. FRI 0124(2018).

Disclosure of Interests:

None declared

GGC Repeat Expansion of NOTCH2NLC in Adult Patients with Leukoencephalopathy

Leukoencephalopathies comprise a broad spectrum of disorders, but the genetic background of adult leukoencephalopathies has rarely been assessed. In this study, we analyzed 101 Japanese patients with genetically unresolved adult leukoencephalopathy using whole-exome sequencing and repeat-primed polymerase chain reaction for detecting GGC expansion in NOTCH2NLC. NOTCH2NLC was recently identified as the cause of neuronal intranuclear inclusion disease. We found 12 patients with GGC expansion in NOTCH2NLC as the most frequent cause of adult leukoencephalopathy followed by NOTCH3 variants in our cohort. Furthermore, we found 1 case with de novo GGC expansion, which might explain the underlying pathogenesis of sporadic cases. ANN NEUROL 2019;86:962-968.

Non-traumatic Acute Epidural Hematoma in Multiple Sclerosis Treated With Fingolimod

Fingolimod acts as a functional antagonist of the sphingosine-1-phosphate receptor and is widely used for relapsing-remitting multiple sclerosis (MS). Here we report the first case of non-traumatic acute epidural hematoma in a relapsing-remitting MS patient treated with fingolimod. Fingolimod might increase the risk of hemorrhage by enhancing vasospasm and causing vascular disruption. Switching fingolimod to other disease-modifying drugs, including dimethyl fumarate, should be considered when non-traumatic hemorrhage is observed in MS patients.

An acute encephalopathy with reduced diffusion in BRAF-associated cardio-facio-cutaneous syndrome

BACKGROUND

Cardio-facio-cutaneous syndrome (CFCS) is a rare genetic disorder characterized by cardiovascular anomalies, dysmorphic faces, ectodermal abnormalities and developmental delays. Mutations in BRAF and other RAS-MAPK pathway-associated genes are commonly identified in patients with CFCS. While this molecular pathway is known to be associated with neuro-inflammatory conditions, only one case with CFCS has been reported thus far to develop acute encephalopathy in childhood.

CASE REPORT

A 3-year-old boy with dysmorphic features and mild psychomotor delay developed acute encephalopathy. After a 45-min long, generalized seizure, the magnetic resonance imaging revealed that the restricted diffusion signals spread to the bilateral subcortical white matters on day 1 of illness. Despite the 14 days of intensive care, the acute symptoms of encephalopathy left him intractable epilepsy and severe neurocognitive impairments. The whole-exome sequencing analysis identified a de novo heterozygous mutation of BRAF (NM_004333:p.Thr241Met) in this case.

CONCLUSION

The present case suggests that the hyperactive condition of ERK signals might augment the development of acute encephalopathy and post-encephalopathic epilepsy in childhood.

Cerebrospinal fluid level of Nogo receptor 1 antagonist lateral olfactory tract usher substance (LOTUS) correlates inversely with the extent of neuroinflammation

Background

Although inflammation in the central nervous system is responsible for multiple neurological diseases, the lack of appropriate biomarkers makes it difficult to evaluate inflammatory activities in these diseases. Therefore, a new biomarker reflecting neuroinflammation is required for accurate diagnosis, appropriate therapy, and comprehension of pathogenesis of these neurological disorders. We previously reported that the cerebrospinal fluid (CSF) concentration of lateral olfactory tract usher substance (LOTUS), which promotes axonal growth as a Nogo receptor 1 antagonist, negatively correlates with disease activity in multiple sclerosis, suggesting that variation in LOTUS reflects the inflammatory activities and is a useful biomarker to evaluate the disease activity. To extend this observation, we analyzed the variation of LOTUS in the CSF of patients with bacterial and viral meningitis, which are the most common neuroinflammatory diseases.

Methods

CSF samples were retrospectively obtained from patients with meningitis (n = 40), who were followed up by CSF study at least twice, and from healthy controls (n = 27). Patients were divided into bacterial (n = 14) and viral meningitis (n = 18) after exclusion of eight patients according to the criteria of this study. LOTUS concentrations, total protein levels, and CSF cell counts in the acute and recovery phases were analyzed chronologically. We also used lipopolysaccharide-injected mice as a model of neuroinflammation to evaluate LOTUS mRNA and protein expression in the brain.

Results

Regardless of whether meningitis was viral or bacterial, LOTUS concentrations in the CSF of patients in acute phase were lower than those of healthy controls. As the patients recovered from meningitis, LOTUS levels in the CSF returned to the normal range. Lipopolysaccharide-injected mice also exhibited reduced LOTUS mRNA and protein expression in the brain.

Conclusions

CSF levels of LOTUS correlated inversely with disease activity in both bacterial and viral meningitis, as well as in multiple sclerosis, because neuroinflammation downregulated LOTUS expression. Our data strongly suggest that variation of CSF LOTUS is associated with neuroinflammation and is useful as a biomarker for a broader range of neuroinflammatory diseases.

A case of severe movement disorder with GNAO1 mutation responsive to topiramate

We report the case of a 19-year-old female patient who had progressive chorea associated with a GNAO1 mutation. Chorea was refractory to multiple anticonvulsants, and the patient suffered from tiapride-induced neuroleptic malignant syndrome. After identification of a GNAO1 missense mutation at the age of 18years, topiramate treatment was initiated and the frequency of chorea decreased dramatically. The efficacy of topiramate may have been related to the inhibitory modulation of voltage-activated Ca²⁺ channels. Given the side effects and complications associated with neuroleptics and deep brain stimulation, respectively, topiramate is recommended for the first-line management of severe chorea associated with a GNAO1 mutation.

Biallelic TBCD Mutations Cause Early-Onset Neurodegenerative Encephalopathy

We describe four families with affected siblings showing unique clinical features: early-onset (before 1 year of age) progressive diffuse brain atrophy with regression, postnatal microcephaly, postnatal growth retardation, muscle weakness/atrophy, and respiratory failure. By whole-exome sequencing, we identified biallelic TBCD mutations in eight affected individuals from the four families. TBCD encodes TBCD (tubulin folding co-factor D), which is one of five tubulin-specific chaperones playing a pivotal role in microtubule assembly in all cells. A total of seven mutations were found: five missense mutations, one nonsense, and one splice site mutation resulting in a frameshift. In vitro cell experiments revealed the impaired binding between most mutant TBCD proteins and ARL2, TBCE, and β-tubulin. The in vivo experiments using olfactory projection neurons in Drosophila melanogaster indicated that the TBCD mutations caused loss of function. The wide range of clinical severity seen in this neurodegenerative encephalopathy may result from the residual function of mutant TBCD proteins. Furthermore, the autopsied brain from one deceased individual showed characteristic neurodegenerative findings: cactus and somatic sprout formations in the residual Purkinje cells in the cerebellum, which are also seen in some diseases associated with mitochondrial impairment. Defects of microtubule formation caused by TBCD mutations may underlie the pathomechanism of this neurodegenerative encephalopathy.

De novo p.Arg756Cys mutation of ATP1A3 causes an atypical form of alternating hemiplegia of childhood with prolonged paralysis and choreoathetosis

Background

Alternating hemiplegia of childhood (AHC) is a rare neurological disorder that manifests recurrent attacks of hemiplegia, oculogyric, and choreoathetotic involuntary movements. De novo mutations in ATP1A3 cause three types of neurological diseases: AHC; rapid-onset dystonia-Parkinsonism (RDP); and cerebellar ataxia, areflexia, pes cavus, optic atrophy, and sensorineural hearing loss (CAPOS) syndromes. It remains to be determined whether or not a rare mutation in ATP1A3 may cause atypical phenotypes.

Case presentation

A 7-year-old boy presented with recurrent symptoms of generalized paralysis since 1 year and 5 months of age. Hypotonia, dystonia, and choreoathetosis persisted with exacerbation under febrile conditions, but no cerebellar ataxia had ever evolved in 6 years. Whole-exome sequencing (WES) was performed to determine his genetic background, and mutations were validated by the Sanger method. Crude protein extracts were prepared from the cultured cells, and expression of the wild-type or mutant ATP1A3 proteins were analyzed by Western blotting. WES identified a de novo pathogenic mutation in ATP1A3 (c.2266C > T:p.R756C) for this patient. A literature overview of two reported cases with p.R756C and p.R756H mutations showed both overlapping and distinct phenotypes when compared with those of the present case. The expression of the mutant form (R756C) of ATP1A3 did not differ markedly from that of the wild-type and D801N proteins.

Conclusions

This study confirmed that p.R756C mutation of ATP1A3 cause atypical forms of AHC-associated disorders. The wide spectra of neurological phenotypes in AHC are linked to as-yet-unknown deficits in the functions of mutant ATP1A3.

Electronic supplementary material

The online version of this article (doi:10.1186/s12883-016-0680-6) contains supplementary material, which is available to authorized users.

Panventriculomegaly with a wide foramen of Magendie and large cisterna magna

OBJECT The authors' goal in this paper is to provide the first clinical, radiological, and genetic studies of panventriculomegaly (PaVM) defined by a wide foramen of Magendie and large cisterna magna. METHODS Clinical and brain imaging data from 28 PaVM patients (including 10 patients from 5 families) were retrospectively studied. Five children were included. In adult patients, the age at onset was 56.0 ± 16.7 years. Tetraventricular dilation, aqueductal opening with flow void on T2-weighted images, and a wide foramen of Magendie and large cisterna magna (wide cerebrospinal fluid space at the fourth ventricle outlet) were essential MRI findings for PaVM diagnosis. 3D fast asymmetrical spin echo sequences were used for visualization of cistern membranes. Time-spatial labeling inversion pulse examination was performed to analyze cerebrospinal fluid movement. Copy number variations were determined using high-resolution microarray and were validated by quantitative polymerase chain reaction with breakpoint sequencing. RESULTS Adult patients showed gait disturbance, urinary dysfunction, and cognitive dysfunction. Five infant patients exhibited macrocranium. Patients were divided into 2 subcategories, those with or without downward bulging third ventricular floors and membranous structures in the prepontine cistern. Patients with bulging floors were successfully treated with endoscopic third ventriculostomy. Genetic analysis revealed a deletion in DNAH14 that encodes a dynein heavy chain protein associated with motile cilia function, and which co-segregated with patients in a family without a downward bulging third ventricular floor. CONCLUSIONS Panventriculomegaly with a wide foramen of Magendie and a large cisterna magna may belong to a subtype of congenital hydrocephalus with familial accumulation, younger age at onset, and symptoms of normal pressure hydrocephalus. In addition, a family with PaVM has a gene mutation associated with dysfunction of motile cilia.

De Novo 17q24.2-q24.3 microdeletion presenting with generalized hypertrichosis terminalis, gingival fibromatous hyperplasia, and distinctive facial features

Generalized hypertrichosis is a feature of several genetic disorders, and the nosology of these entities is still provisional. Recent studies have implicated chromosome 17q24.2-q24.3 microdeletion and the reciprocal microduplication in a very rare form of congenital generalized hypertrichosis terminalis (CGHT) with or without gingival hyperplasia. Here, we report on a 5-year-old Egyptian girl born to consanguineous parents. The girl presented with CGHT and gingival hyperplasia for whom we performed detailed clinical, pathological, and molecular studies. The girl had coarse facies characterized by bilateral epicanthic folds, thick and abundant eyelashes, a broad nose, full cheeks, and lips that constituted the distinctive facial features for this syndrome. Biopsy of the gingiva showed epithelial marked acanthosis and hyperkeratosis with hyperplastic thick collagen bundles and dense fibrosis in the underlying tissues. Array analysis indicated a 17q24.2-q24.3 chromosomal microdeletion. We validated this microdeletion by real-time quantitative PCR and confirmed a perfect co-segregation of the disease phenotype within the family. In summary, this study indicates that 17q24.2-q24.3 microdeletion caused CGHT with gingival hyperplasia and distinctive facies, which should be differentiated from the autosomal recessive type that lacks the distinctive facies.

Phenotypic spectrum of GNAO1 variants: epileptic encephalopathy to involuntary movements with severe developmental delay

De novo GNAO1 variants have been found in four patients including three patients with Ohtahara syndrome and one patient with childhood epilepsy. In addition, two patients showed involuntary movements, suggesting that GNAO1 variants can cause various neurological phenotypes. Here we report an additional four patients with de novo missense GNAO1 variants, one of which was identical to that of the previously reported. All the three novel variants were predicted to impair Gαo function by structural evaluation. Two patients showed early-onset epileptic encephalopathy, presenting with migrating or multifocal partial seizures in their clinical course, but the remaining two patients showed no or a few seizures. All the four patients showed severe intellectual disability, motor developmental delay, and involuntary movements. Progressive cerebral atrophy and thin corpus callosum were common features in brain images. Our study demonstrated that GNAO1 variants can cause involuntary movements and severe developmental delay with/without seizures, including various types of early-onset epileptic encephalopathy.

A case of autism spectrum disorder arising from a de novo missense mutation in POGZ

Autism spectrum disorder (ASD) is a clinically heterogeneous psychiatric disorder with various genetic backgrounds. Here, we report a novel mutation in the pogo transposable element-derived protein with zinc finger domain gene (POGZ) identified by trio-based whole exome sequencing. To date, a total of seven de novo POGZ mutations in ASD have been reported. POGZ contains a total of five functional domains, and this study reports the first de novo missense mutation in the centromere protein B-like DNA-binding domain. POGZ is highly expressed in the human fetal brain and is involved in mitosis and the regulation of neuronal proliferation. Therefore its loss-of-function or pathogenic missense mutations are likely to be causative of ASD.

A de novo 1.4-Mb deletion at 21q22.11 in a boy with developmental delay

Monosomy 21 is a very rare chromosomal abnormality. At least 45 patients with partial deletion involving 21q11 have been reported. Here, we report a Japanese boy who presented with pre- and postnatal growth delays, psychomotor developmental delay, microcephaly, and iris coloboma. Cytogenetic analysis revealed a de novo 1.4-Mb deletion at 21q22.11 containing 19 protein-coding RefSeq genes. We compared the clinical phenotypes between the present patient and 16 previously reported patients with a deleted region associated with postnatal growth delay and psychomotor developmental delay. Interestingly, ITSN1 was the only gene deleted or disrupted in all cases; this gene is known to be associated with intellectual disability. Microcephaly and brain structural abnormalities including polymicrogyria and agenesis/hypoplasia of the corpus callosum may also result from haploinsufficiency of ITSN1, highlighting its clinical significance for the neurological features of patients with monosomy 21.

Duplication of the NPHP1 gene in patients with autism spectrum disorder and normal intellectual ability: a case series

Autism spectrum disorder is a neurodevelopmental disorder characterized by impairments in social interactions, reduced verbal communication abilities, stereotyped repetitive behaviors, and restricted interests. It is a complex condition caused by genetic and environmental factors; the high heritability of this disorder supports the presence of a significant genetic contribution. Many studies have suggested that copy-number variants contribute to the etiology of autism spectrum disorder. Recently, copy-number variants of the nephronophthisis 1 gene have been reported in patients with autism spectrum disorder. To the best of our knowledge, only six autism spectrum disorder cases with duplications of the nephronophthisis 1 gene have been reported. These patients exhibited intellectual dysfunction, including verbal dysfunction in one patient, below-average verbal intellectual ability in one patient, and intellectual disability in four patients. In this study, we identified nephronophthisis 1 duplications in two unrelated Japanese patients with autism spectrum disorder using a high-resolution single-nucleotide polymorphism array. This report is the first to describe a nephronophthisis 1 duplication in an autism spectrum disorder patient with an average verbal intelligence quotient and an average performance intelligence quotient. However, the second autism spectrum disorder patient with a nephronophthisis 1 duplication had a below-average performance intelligence quotient. Neither patient exhibited physical dysfunction, motor developmental delay, or neurological abnormalities. This study supports the clinical observation of nephronophthisis 1 duplication in autism spectrum disorder cases and might contribute to our understanding of the clinical phenotype that arises from this duplication.

Co-occurrence of 22q11 deletion syndrome and HDR syndrome

22q11 deletion syndrome is one of the most common chromosomal deletion syndromes and is usually caused by a 1.5-3.0 Mb deletion at chromosome 22q11.2. It is characterized by hypocalcemia resulting from hypoplasia of the parathyroid glands, hypoplasia of the thymus, and defects of the cardiac outflow tract. We encountered a Japanese boy presenting with an unusually severe phenotype of 22q11 deletion syndrome, including progressive renal failure and severe intellectual disabilities. Diagnostic testing using fluorescent in situ hybridization revealed deletion of the 22q11 region, but this did not explain the additional complications. Copy number analysis was therefore performed using whole genome single nucleotide polymorphism (SNP) assay, which identified an additional de novo deletion at 10p14. This region is the locus for hypoparathyroidism, deafness, and renal dysplasia (HDR) syndrome caused by haploinsufficiency of GATA3. Together, these two syndromes sufficiently explain the patient's phenotype. This is the first known case report of the co-occurrence of 22q11 deletion syndrome and HDR syndrome. As the two syndromes overlap clinically, this study indicates the importance of carrying out careful clinical and genetic assessment of patients with atypical clinical phenotypes or unique complications. Unbiased genetic analysis using whole genome copy number SNP arrays is especially useful for detecting such rare double mutations.

[A case of mediastinal esophago-bronchogenic cyst associated with high serum level of CA 19-9]

We report a case of mediastinal esophago-bronchogenic cyst in a patient with a high serum level of CA 19-9. A 49-year-old man presented with a complaint of dysphagia. Chest X-ray, CT, and MRI showed posterior mediastinal cystic shadow which was diagnosed preoperatively. The serum level of CA 19-9 was 158 U/ml. We underwent extirpation of the cyst through video-assisted thoracoscopic surgery (VATS) and confirmed to be a bronchogenic cyst histologically. The serum level of CA 19-9 returned to normal after the operation.