Two novel cases of biallelic SMPD4 variants with brain structural abnormalities.

Sphingomyelin phosphodiesterase 4 (SMPD4) encodes a member of the Mg2+-dependent, neutral sphingomyelinase family that catalyzes the hydrolysis of the phosphodiester bond of sphingomyelin to form phosphorylcholine and ceramide. Recent studies have revealed that biallelic loss-of-function variants of SMPD4 cause syndromic neurodevelopmental disorders characterized by microcephaly, congenital arthrogryposis, and structural brain anomalies. In this study, three novel loss-of-function SMPD4 variants were identified using exome sequencing (ES) in two independent patients with developmental delays, microcephaly, seizures, and brain structural abnormalities. Patient 1 had a homozygous c.740_741del, p.(Val247Glufs*21) variant and showed profound intellectual disability, hepatomegaly, a simplified gyral pattern, and a thin corpus callosum without congenital dysmorphic features. Patient 2 had a compound heterozygous nonsense c.2124_2125del, p.(Phe709*) variant and splice site c.1188+2dup variant. RNA analysis revealed that the c.1188+2dup variant caused exon 13 skipping, leading to a frameshift (p.Ala406Ser*6). In vitro transcription analysis using minigene system suggested that mRNA transcribed from mutant allele may be degraded by nonsense-mediated mRNA decay system. He exhibited diverse manifestations, including growth defects, muscle hypotonia, respiratory distress, arthrogryposis, insulin-dependent diabetes mellitus, sensorineural hearing loss, facial dysmorphism, and various brain abnormalities, including cerebral atrophy, hypomyelination, and cerebellar hypoplasia. Here, we review previous literatures and discuss the phenotypic diversity of SMPD4-related disorders.

Effect of levodopa on pathological gait in Dravet syndrome: A randomized crossover trial using three-dimensional gait analysis.

OBJECTIVE: Individuals with Dravet syndrome (DS) exhibit progressive gait disturbance. No quantitative studies have been conducted to evaluate the effectiveness of medication for gait disturbance. Therefore, the aim of this study was to evaluate the effectiveness of levodopa for pathological gait in people with DS using three-dimensional gait analysis (3DGA). METHODS: Nine individuals with DS, ages 6-20 years, participated in a crossover study of levodopa and were randomly assigned to the levodopa precedence or no levodopa precedence group. Levodopa/carbidopa hydrate was prescribed at a dose of 5 mg/kg/day (body weight <60 kg) or 300 mg/day (body weight ≥60 kg). The medication was taken for 4-6 weeks (4-week washout period). 3DGA was performed three times before the study, with and without levodopa. A mixed-effects model was used to evaluate the effectiveness of levodopa. The primary outcome was the change in the Gait Deviation Index (GDI). In addition, spatiotemporal gait parameters, 6-minute walking distance (6MD), and balance were evaluated. The correlation between the effectiveness of levodopa and age or gait performance before starting levodopa was analyzed. RESULTS: Levodopa improved the GDI by 4.2 points, (p = .029), 6MD by 52 m (p = .002), and balance test result by 4.1 mm (p = .011) in participants with DS. No severe adverse events were observed, with the exception of one participant, who exhibited fever and consequently stopped taking levodopa. Levodopa was more effective in younger participants with a higher baseline gait performance. SIGNIFICANCE: Our randomized crossover trial showed that levodopa has the potential to improve gait disturbance in people with DS.

Haploinsufficiency of PRR12 causes a spectrum of neurodevelopmental, eye, and multisystem abnormalities.

PURPOSE: Proline Rich 12 (PRR12) is a gene of unknown function with suspected DNA-binding activity, expressed in developing mice and human brains. Predicted loss-of-function variants in this gene are extremely rare, indicating high intolerance of haploinsufficiency. METHODS: Three individuals with intellectual disability and iris anomalies and truncating de novo PRR12 variants were described previously. We add 21 individuals with similar PRR12 variants identified via matchmaking platforms, bringing the total number to 24. RESULTS: We observed 12 frameshift, 6 nonsense, 1 splice-site, and 2 missense variants and one patient with a gross deletion involving PRR12. Three individuals had additional genetic findings, possibly confounding the phenotype. All patients had developmental impairment. Variable structural eye defects were observed in 12/24 individuals (50%) including anophthalmia, microphthalmia, colobomas, optic nerve and iris abnormalities. Additional common features included hypotonia (61%), heart defects (52%), growth failure (54%), and kidney anomalies (35%). PrediXcan analysis showed that phecodes most strongly associated with reduced predicted PRR12 expression were enriched for eye- (7/30) and kidney- (4/30) phenotypes, such as wet macular degeneration and chronic kidney disease. CONCLUSION: These findings support PRR12 haploinsufficiency as a cause for a novel disorder with a wide clinical spectrum marked chiefly by neurodevelopmental and eye abnormalities.

In vitro functional analysis of four variants of human asparagine synthetase.

The loss-of-function variants of the human asparagine synthetase (ASNS) gene cause asparagine synthetase deficiency (ASNSD). Diagnosis of ASNSD requires genetic tests because a specific biochemical diagnostic for ASNSD is not available. There are a few reports describing the functional evaluation of ASNS variants. Therefore, in vitro methods are needed to evaluate the detected variants in patients. In this report, five types of human ASNS proteins (wild-type and our reported four variants: p.Leu145Ser, p.Leu247Trp, p.Val489Asp, and p.Trp541Cysfs*5) were expressed in silkworm using a baculoviral expression system. An enzymatic activity assay of ASNS was performed, and the concentration of asparagine by ninhydrin and High Performance Liquid Chromatography methods using the purified recombinant proteins was measured. We established ASNS deficient HEK293 cells using the CRISPR/Cas9 method and evaluated the growth of cells without asparagine after transduction of ASNS variants with a lentiviral expression system. The four ASNS variants displayed significantly low enzymatic activity. The ASNS deficient HEK293 cells transduced with wild-type ASNS grew without asparagine, whereas cells transduced with the variants did not grow or showed significantly slower growth than cells transduced with wild-type ASNS. Herein, we established a method for evaluating the enzymatic activity of the recombinant human ASNS variants. The results of the cell-based assay corroborated the results of the enzymatic activity. These methods should enable the evaluation of the pathogenicity of ASNS variants.

FDG-PET/CT for Detection of Extramedullary Disease in 2 Pediatric Patients With AML.

Positron emission tomography combined with computed tomography (PET/CT) is a promising diagnostic procedure for the detection of extramedullary disease (EMD) in acute myeloid leukemia. We studied 2 children with acute myeloid leukemia who underwent PET to assess for EMD at diagnosis as well as in remission. We detected 5 EMD lesions in 2 cases with PET, only 2 of which were detectable on clinical examination. Our cases show PET's increased sensitivity over physical examination alone in assessing and monitoring the extent of this disease.

De novo KIF1A mutations cause intellectual deficit, cerebellar atrophy, lower limb spasticity and visual disturbance.

Recently, de novo KIF1A mutations were identified in patients with intellectual disability, spasticity and cerebellar atrophy and/or optic nerve atrophy. In this study, we analyzed a total of 62 families, including 68 patients with genetically unsolved childhood cerebellar atrophy, by whole-exome sequencing (WES). We identified five de novo missense KIF1A mutations, including only one previously reported mutation (p.Arg316Trp). All the mutations are located in the motor domain of KIF1A. In all patients, initial symptom onset was during the infantile period, and included developmental delay in three patients and gait disturbance in two. Thereafter, they showed gait disturbances, exaggerated deep tendon reflexes, cerebellar symptoms and cerebellar atrophy on brain magnetic resonance imaging. Four patients showed lower limb spasticity, upper limb clumsiness and visual disturbances. Nerve conduction study revealed peripheral neuropathy in three patients. This study further delineates clinical features of de novo KIF1A mutations. Genetic testing of KIF1A should be considered in children with developmental delay, cerebellar atrophy and pyramidal features.

Differences in fluorodeoxyglucose positron emission tomography/computed tomography findings between elderly onset rheumatoid arthritis and polymyalgia rheumatica.

OBJECTIVES: To compare the fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) findings in patients with elderly-onset rheumatoid arthritis (EORA) with those in patients with polymyalgia rheumatica (PMR), two conditions with similar clinical presentations. METHODS: We retrospectively analyzed the FDG-PET/CT findings in 10 patients with EORA and 27 patients with PMR admitted to our department between 2006 and 2012. RESULTS: No significant difference was observed in the median patient ages at the time of FDG-PET/CT scans in the EORA and PMR groups (73.5 vs. 78.0 years, respectively). Significant differences in both FDG uptake scores and standardized uptake values were observed between the two groups in the ischial tuberosities, spinous processes, and wrists. No significant differences were detected in the shoulders and hips. However, specific uptake patterns were observed in each group: circular and linear uptake patterns were observed around the humeral head in the EORA group, whereas focal and non-linear uptake patterns were observed in the PMR group. Moreover, focal uptake in front of the hip joint, indicating iliopectineal bursitis, tended to be limited to the PMR group. High sensitivity (92.6%) and specificity (90%) were observed for PMR diagnoses when at least three of the following five items were satisfied: characteristic findings of shoulder and iliopectineal bursitis, FDG uptake in ischial tuberosities and spinal spinous processes, and lack of FDG uptake in the wrists. CONCLUSION: The differences in the degree of uptake at each lesion and in uptake patterns at the shoulders and hips are potentially useful for obtaining a definitive diagnosis.

Clinical and genetic characterization of Japanese sporadic cases of periodic Fever, aphthous stomatitis, pharyngitis and adenitis syndrome from a single medical center in Japan.

PURPOSE: To investigate clinical presentation, genetic background and cytokine profile of Japanese sporadic cases of periodic fever, aphthous stomatitis, pharyngitis and adenitis (PFAPA) syndrome. METHODS: Nine PFAPA syndrome patients were recruited. DNA sequence analysis of auto inflammatory disorder susceptibility genes, MEFV, MVK, NLRP3, and TNFRSF1A, were performed. Serum cytokine levels and monocyte IL-1ß levels were measured by ELISA. RESULTS: The study population consisted of six males and three females (mean age of onset 26.8 months). Febrile episodes lasted 3-6 days with symptom-free intervals ranging from 2 to 12 weeks. Fever was accompanied by pharyngitis (n = 8), aphthous stomatitis (n = 4), and cervical adenitis (n = 5). White blood cells and C-reactive protein were increased during the attack phase. Mean IgD serum levels were 7.32 ± 9.51 mg/dl during the attack phase, and were mildly elevated in two patients. Heterozygous MEFV, NLRP3 and TNFRSF1A variants were detected in four, one and three cases, respectively. Serum TNF-α and IL-18 levels were elevated during the attack-free and attack periods compared with controls. Other cytokines, IL-1ß, IL-1ra, IL-6, and sTNFR1, were only increased during the attack phase. Oral prednisolone was administered to eight patients and immediately reduced fever. Tonsillectomy performed in five patients induced cessation of fever in four patients. One case with repeated fever attacks after tonsillectomy showed increased monocyte IL-1ß production, similar to the other active case with genetic variants of auto inflammatory disorder-associated genes. CONCLUSIONS: Japanese PFAPA syndrome patients may have cytokine regulation dysfunction as a result of genetic variants of auto inflammatory disorder-associated genes.

Utility of fluorodeoxyglucose positron emission tomography/computed tomography for early diagnosis and evaluation of disease activity of relapsing polychondritis: a case series and literature review.

OBJECTIVE: Relapsing polychondritis (RPC) is relatively rare and early diagnosis is difficult. We investigated the utility of fluorodeoxyglucose (FDG)-PET/CT for the diagnosis of RPC and evaluation of disease activity. METHODS: Five RPC patients undergoing FDG-PET/CT in our hospital between 2006 and 2012 were studied. Eight RPC cases examined by PET reported in the literature were also assessed. Data from a total of 13 patients were analysed. RESULTS: Typical FDG accumulation was noted in the tracheobronchial trees of nine patients, the costal cartilage of five, joints of five, larynx of four, nasal cavity/paranasal sinuses of three, auricles of three, lymph nodes of three and the aorta of one. One patient showed nasal chondritis on a PET scan despite the absence of nasal changes on physical examination. Of five patients with costochondritis, four remained asymptomatic. Of nine patients with airway FDG accumulation, eight developed respiratory symptoms and all had CT abnormalities. In the other patient, airway FDG accumulation was evident despite the absence of airway symptoms and a lack of abnormalities in the respiratory function test and CT. PET also revealed bronchial chondritis in asymptomatic patients. The mean maximum standardized uptake values (SUVmax) of the upper and lower airways was 5.79 (s.d. 2.87) and 6.47 (s.d. 4.08), respectively. In five patients with a PET after treatment, FDG accumulation had diminished with symptomatic and inflammatory improvement. CONCLUSION: FDG-PET/CT is a potentially powerful tool for the early diagnosis of RPC, especially in patients without easily biopsied organ involvement. This modality also facilitates evaluation of disease extent and disease activity during treatment.

Large vessel vasculitis in elderly patients: early diagnosis and steroid-response evaluation with FDG-PET/CT and contrast-enhanced CT.

Large vessel vasculitis (LVV) is an often-reported cause of inflammation of unknown origin (IUO) in elderly people. The objective of this study was to describe the usefulness of fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) and contrast-enhanced CT in early diagnosis and treatment follow-up of patients with LVV presenting as elderly onset IUO. We retrospectively compared contrast-enhanced CT findings and FDG-PET/CT findings of the patients diagnosed with LVV and 11 controls; all subjects were 50 years of age or older. We evaluated maximum standardised uptake value (SUV(max)) and PET score of the aortic wall for quantitative comparison of FDG-PET/CT findings. We measured the aortic wall thickness (W) and its ratio against the radius (W/R) for quantitative comparison of aortic wall thickening by contrast-enhanced CT. After steroid treatment, we compared these values with those pre-treatment. Of 124 patients who were hospitalised due to advanced age and IUO, 88 underwent FDG-PET/CT and contrast-enhanced CT. Abnormal findings were observed on images from 78 patients. The findings were indicative of LVV in 13 patients (10.5 %), of whom more than half had only non-specific symptoms. Patients with LVV had significantly higher aortic wall SUV(max) (3.85 vs. 1.95), PET scores by FDG-PET/CT, and aortic wall thicknesses by contrast-enhanced CT (3.8 vs. 2.6 mm) than controls. Significant improvement in aortic wall thickening was evidenced by reduced PET scores and by contrast-enhanced CT findings in patients who were followed up after treatment. LVV is an important cause of IUO with non-specific symptoms in elderly patients. Imaging examination comprising contrast-enhanced CT and FDG-PET/CT is useful for early diagnosis and early treatment evaluation of LVV, allowing for amelioration of reversible aortic wall thickening.

Facial palsy as an unusual presenting symptom associated with acute myeloid leukemia.

Extramedullary infiltration is common in acute myeloid leukemia (AML) patients. Although AML can cause neurological symptoms, especially when associated with extramedullary infiltration, a presenting manifestation of facial palsy is rare. We report on a 1-year-old boy who developed right facial palsy. Detailed examination led to a diagnosis of AML (French-American-British classification M1). Magnetic resonance imaging enhanced with gadolinium-diethylenetriamine penta-acetic acid showed abnormal enhancement of the right facial nerve, which disappeared after chemotherapy. AML should be considered as a differential diagnosis of facial palsy. Enhanced magnetic resonance imaging may be useful for diagnosing facial palsy associated with AML and for evaluating treatment outcome.

Clinical value of ¹8F-fluoro-dexoxyglucose positron emission tomography/computed tomography in patients with adult-onset Still's disease: a seven-case series and review of the literature.

OBJECTIVES: While there are a few reports describing 18F-fluoro-dexoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) findings in patients with adult-onset Still's disease (AOSD), no summary report has yet been published. In this study, we evaluated the usefulness of FDG-PET/CT for diagnosis and activity evaluation in patients with AOSD by summarizing the findings of our patients and those reported in the literature. METHODS: Seven consecutive AOSD patients who had undergone PET/CT at our department between 2007 and 2012 were included. We evaluated FDG uptake for characteristic findings in patients with AOSD. In addition, we reviewed the literature on seven previously reported AOSD patients who had undergone PET/CT. RESULTS: FDG accumulation was positive mainly in the bone marrow (100%), spleen (90.9%), lymph nodes (80.0%) and joints (75.0%). In addition, FDG uptake was positive in the pericardium, pleura, salivary glands, eyelids, muscle and major blood vessels. Six patients underwent follow-up FDG PET/CT for evaluation of treatment efficacy. Follow-up PET/CT showed diminished FDG accumulation in the bone marrow, spleen and lymph nodes, with maximum standardized uptake value (SUVmax) being substantially reduced from 4.03 ± 0.95 to 2.20 ± 0.75 (p = 0.04), 4.04 ± 1.10 to 2.55 ± 1.13 (p = 0.04) and 5.63 ± 4.99 to 2.10 ± 1.91 (p = 0.11), respectively. No significant correlation was found between SUVmax in each lesion and the laboratory data, except for a significant correlation between lactate dehydrogenase (LDH) and spleen SUV. CONCLUSIONS: FDG-PET/CT is useful for long-term assessments of AOSD activity in individual patients. However, PET/CT findings alone are not sufficient to make a differential diagnosis of AOSD versus malignant lymphoma.

[Additional external radiotherapy to multiple metastases originating from thymic neuroendocrine tumor following peptide receptor radionuclide therapy: a case report].

We describe the case of a 60-year-old man suffering from an advanced thymic neuroendocrine tumor with left supraclavicular lymph node and multiple bone metastases. The patient initially underwent systemic therapy with somatostatin analogues. Thereafter, peptide receptor radionuclide therapy (PRRT) was considered because the lesions had remained stable despite the pharmacological therapy. PRRT was performed 10 months after the initial treatment in a European hospital. Eighteen months after the treatment, cranial nerve palsy arising from skull base metastases and Horner's syndrome induced by left supraclavicular lymph node metastases became exacerbated. Therefore, a course of external radiotherapy was performed with palliative intent in our hospital. During the radiotherapy planning, the biodistribution of 111In-octreotide was examined to determine whether the absorbed dose of the previous PRRT was acceptable. As a result, external radiotherapy was performed, and an acute radiation reaction was observed; the severity of the reaction was typical of reactions to neck radio-therapy. The treatment course of the present case was considered to be instructive because PRRT cannot be performed in Japan at present.

Prognostic value of post-treatment (18)F-FDG PET/CT for advanced head and neck cancer after combined intra-arterial chemotherapy and radiotherapy.

OBJECTIVE: To clarify the prognostic value of post-treatment (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) in patients with advanced head and neck squamous cell carcinoma (HNSCC) after combined intra-arterial chemotherapy and radiotherapy (IACR). METHODS: Thirty-six patients with HNSCC who underwent IACR were recruited. The period from the end of IACR to the last post-treatment (18)F-FDG PET/CT examination was 8-12 weeks. Both patient-based and lesion-based analyses were used to evaluate the PET/CT images. For lesion-based analysis, 36 regions (12 lesions of recurrences and 24 scars at primary sites) were selected. The Kaplan-Meier method was used to assess the overall survival (OS) stratified by (18)F-FDG uptake or visual interpretation results. RESULTS: Twelve patients with recurrence were identified by six months after IACR. The sensitivity and specificity in the patient-based analysis were 67% (8/12) and 88% (21/24), respectively. The mean OS was estimated to be 12.1 months (95% CI, 6.3-18.0 months) for the higher maximum standardized uptake value (SUVmax) group (n=7) and 44.6 months (95% CI, 39.9-49.3 months) for the lower SUVmax group (n=29). OS in the higher SUVmax group (cut-off point, 6.1) or positive visual interpretation group was significantly shorter than that in the lower SUVmax or negative visual interpretation group (P<0.001 and P<0.05, respectively). CONCLUSIONS: The SUVmax and visual interpretation of HNSCC on post-IACR (18)F-FDG PET/CT can provide prognostic survival estimates.

Spontaneous Remission of Epileptic Seizures Following Norovirus Infection in a Patient With DNM1 Encephalopathy.

Epileptic seizures can be worsened by infections; however, they sometimes disappear or decrease after an acute viral infection, although this is rare. We report the spontaneous remission of epileptic seizures following norovirus-induced viral gastroenteritis in a boy with DNM1 encephalopathy. He had clonic seizures daily from the age of two months and developed epileptic spasms at 14 months of age; he was admitted to the hospital at this time. A physical examination revealed hypotonia, strabismus, tongue protrusion with drooping, and widely spaced teeth. Although brain magnetic resonance imaging was unremarkable, electroencephalography revealed frequent occipital spikes. Three days after admission, the patient developed frequent diarrhea without a fever. A rapid immunochromatographic test of norovirus in a stool sample was positive. Immediately after the appearance of diarrhea, the epileptic seizures disappeared. Currently, at the age of five years, the patient has a profound psychomotor developmental delay; he has no verbal expression and is unable to walk. He has experienced involuntary movements of the myoclonus since 10 months of age. Whole-exome sequencing of the patient's DNA revealed the presence of a heterozygous de novo variant of DNM1: c.709C>T (p.Arg237Trp). Although the findings from our patient suggest that underlying neural network abnormalities were ameliorated by immunological mechanisms as a result of the viral infection, further research is needed to clarify the mechanisms behind this spontaneous remission of seizures.

Infantile Epileptic Spasms Syndrome Complicated by Leigh Syndrome and Leigh-Like Syndrome: A Retrospective, Nationwide, Multicenter Case Series.

BACKGROUND: Six percent of patients with Leigh syndrome (LS) present with infantile epileptic spasms syndrome (IESS). However, treatment strategies for IESS with LS remain unclear. This retrospective study aimed to evaluate the efficacy and safety of treatment strategies in patients with IESS complicated by LS and Leigh-like syndrome (LLS). METHODS: We distributed questionnaires to 750 facilities in Japan, and the clinical data of 21 patients from 15 hospitals were collected. The data comprised treatment strategies, including adrenocorticotropic hormone (ACTH) therapy, ketogenic diet (KD) therapy, and antiseizure medications (ASMs); effectiveness of each treatment; and the adverse events. RESULTS: The median age at LS and LLS diagnosis was 7 months (range: 0 to 50), whereas that at the onset of epileptic spasms was 7 (range: 3 to 20). LS was diagnosed in 17 patients and LLS in four patients. Seven, two, five, and seven patients received ACTH + ASMs, ACTH + KD + ASMs, KD + ASMs, and ASMs only, respectively. Four (44%) of nine patients treated with ACTH and one (14%) of seven patients treated with KD achieved electroclinical remission within one month of treatment. No patients treated with only ASMs achieved electroclinical remission. Seven patients (33%) achieved electroclinical remission by the last follow-up. Adverse events were reported in four patients treated with ACTH, none treated with KD therapy, and eight treated with ASMs. CONCLUSION: ACTH therapy shows the best efficacy and rapid action in patients with IESS complicated by LS and LLS. The effectiveness of KD therapy and ASMs in this study was insufficient.