Genetic Analysis Using a Next Generation Sequencing-Based Gene Panel in Patients With Skeletal Dysplasia: A Single-Center Experience.

Skeletal dysplasia (SD), a heterogeneous disease group with rare incidence and various clinical manifestations, is associated with multiple causative genes. For clinicians, accurate diagnosis of SD is clinically and genetically difficult. The development of next-generation sequencing (NGS) has substantially aided in the genetic diagnosis of SD. In this study, we conducted a targeted NGS of 437 genes - included in the nosology of SD published in 2019 - in 31 patients with a suspected SD. The clinical and genetic diagnoses were confirmed in 16 out of the 31 patients, and the diagnostic yield was 51.9%. In these patients, 18 pathogenic variants were found in 13 genes (COL2A1, MYH3, COMP, MATN3, CTSK, EBP, CLCN7, COL1A2, EXT1, TGFBR1, SMAD3, FIG4, and ARID1B), of which, four were novel variants. The diagnosis rate was very high in patients with a suspected familial SD and with radiological evidence indicating clinical SD (11 out of 15, 73.3%). In patients with skeletal involvement and other clinical manifestations including dysmorphism or multiple congenital anomalies, and various degrees of developmental delay/intellectual disability, the diagnosis rate was low (5 out of 16, 31.2%) but rare syndromic SD could be diagnosed. In conclusion, NGS-based gene panel sequencing can be helpful in diagnosing SD which has clinical and genetic heterogeneity. To increase the diagnostic yield of suspected SD patients, it is important to categorize patients based on the clinical features, family history, and radiographic evidence.

A boy with Coffin-Siris syndrome with a novel frameshift mutation in ARID1B.

Coffin-Siris syndrome (OMIM #135900) is an autosomal dominant inherited disorder, characterized by dysmorphic features, congenital anomalies, and developmental delay. We report the clinical and molecular findings in a patient with Coffin-Siris syndrome. A 3-year-and-6-month-old boy presented with developmental delay, distinctive facial features, hypertrichosis, partial agenesis of the corpus callosum, fifth digit nail hypoplasia, congenital anomalies, and growth retardation. Targeted gene panel sequencing identified a novel heterozygous frameshift mutation c.2147_2148insAC in ARID1B which was predicted as a premature stop codon p. (Gln717Argfs*29). This is the second report of Coffin-Siris syndrome in Korea. Targeted gene panel sequencing can be used as an effective tool for the diagnosis of rare complex syndromes such as Coffin-Siris syndrome.

Mild Phenotype of Xq Deletion and 3q Duplication Associated with der(X)t(X;3)(q21.1;q22.1) without Loss of XIST Gene.

We report a 10-year-old female patient with der(X)t(X;3)(q21.1;q22.1), resulting in 3q duplication and Xq deletion. The main clinical feature was primary ovarian failure and there was no abnormal phenotype corresponding to 3q duplication syndrome. This might be explained by the XIST gene at the X-inactivation center on Xq13.2, which was not deleted in this case. The conventional karyotyping was preliminarily reported as 46,X,inv(X) (q13q26) due to the similar banding patterns of Xq13.2-q24 and 3q25.33-q29. This case highlights the value of using a chromosomal microarray as a clinical diagnostic test for individuals with developmental delay or congenital anomalies.

The First Korean Case of Baraitser-Winter Cerebro-Fronto-Facial Syndrome with a Novel Mutation in ACTB Diagnosed Via Targeted Gene Panel Sequencing and Literature Review.

Baraitser-Winter Cerebro-fronto-facial syndrome (BWCFF, OMIM #243310, #614583) is caused by a heterozygous gain-of-function mutation of ACTB and ACTG1 that encodes actin. The syndrome is characterized by striking facial features, structural brain abnormalities, ocular coloboma, hearing loss, cardiac defects, intellectual disabilities, short stature, and developmental delay. We report a two-year-old girl who had distinctive facial features, including hypertelorism, arched eyebrows, bilateral ptosis, short broad nose with a flat nasal tip, long philtrum, retrognathia, low-set ears, and a thin upper lip. In addition, she also exhibited short stature, pectus excavatum, developmental delay, brain malformation, and hearing loss. Targeted gene panel sequencing identified a de novo heterozygous missense variant c.826G>A (p.Glu276Lys) in ACTB This is the first Korean case of BWCFF with a novel mutation in ACTB.

Clinical characteristics and disease progression of retinitis pigmentosa associated with PDE6B mutations in Korean patients.

Due to the genotype-phenotype heterogeneity in retinitis pigmentosa (RP), molecular diagnoses and prediction of disease progression is difficult. This study aimed to report ocular and genetic data from Korean patients with PDE6B-associated RP (PDE6B-RP), and establish genotype-phenotype correlations to predict the clinical course. We retrospectively reviewed targeted next-generation sequencing or whole exome sequencing data for 305 patients with RP, and identified PDE6B-RP in 15 patients (median age, 40.0 years). Amongst these patients, ten previously reported PDE6B variants (c.1280G > A, c.1488del, c.1547T > C, c.1604T > A, c.1669C > T, c.1712C > T, c.2395C > T, c.2492C > T, c.592G > A, and c.815G > A) and one novel variant (c.712del) were identified. Thirteen patients (86.7%) experienced night blindness as the first symptom at a median age of 10.0 years. Median age at diagnosis was 21.0 years and median visual acuity (VA) was 0.20 LogMAR at the time of genetic analysis. Nonlinear mixed models were developed and analysis revealed that VA exponentially decreased over time, while optical coherence tomography parameters linearly decreased, and this was related with visual field constriction. A high proportion of patients with the c.1669C > T variant (7/9, 77.8%) had cystoid macular edema; despite this, patients with this variant did not show a higher rate of functional or structural progression. This study will help clinicians predict functional and structural progression in patients with PDE6B-RP.

A novel de novo heterozygous DYRK1A mutation causes complete loss of DYRK1A function and developmental delay.

Dual-specificity tyrosine phosphorylation-regulated kinase 1 A (DYRK1A) is essential for human development, and DYRK1A haploinsufficiency is associated with a recognizable developmental syndrome and variable clinical features. Here, we present a patient with DYRK1A haploinsufficiency syndrome, including facial dysmorphism, delayed motor development, cardiovascular system defects, and brain atrophy. Exome sequencing identified a novel de novo heterozygous mutation of the human DYRK1A gene (c.1185dup), which generated a translational termination codon and resulted in a C-terminally truncated protein (DYRK1A-E396ter). To study the molecular effect of this truncation, we generated mammalian cell and Drosophila models that recapitulated the DYRK1A protein truncation. Analysis of the structure and deformation energy of the mutant protein predicted a reduction in protein stability. Experimentally, the mutant protein was efficiently degraded by the ubiquitin-dependent proteasome pathway and was barely detectable in mammalian cells. More importantly, the mutant kinase was intrinsically inactive and had little negative impact on the wild-type protein. Similarly, the mutant protein had a minimal effect on Drosophila phenotypes, confirming its loss-of-function in vivo. Together, our results suggest that the novel heterozygous mutation of DYRK1A resulted in loss-of-function of the kinase activity of DYRK1A and may contribute to the developmental delay observed in the patient.

Nonclassic congenital lipoid adrenal hyperplasia diagnosed at 17 months in a Korean boy with normal male genitalia: emphasis on pigmentation as a diagnostic clue.

Congenital lipoid adrenal hyperplasia (CLAH) is one of the most fatal conditions caused by an abnormality of adrenal and gonadal steroidogenesis. CLAH results from loss-of-function mutations of the steroidogenic acute regulatory (STAR) gene; the disease manifests with electrolyte imbalances and hyperpigmentation in neonates or young infants due to adrenocortical hormone deficiencies, and 46, XY genetic male CLAH patients can be phenotypically female. Meanwhile, some patients with STAR mutations develop hyperpigmentation and mild signs of adrenal insufficiency, such as hypoglycemia, after infancy. These patients are classified as having nonclassic CLAH (NCCLAH) caused by STAR mutations that retain partial activity of STAR. We present the case of a Korean boy with normal genitalia who was diagnosed with NCCLAH. He presented with whole-body hyperpigmentation and electrolyte abnormalities, which were noted at the age of 17 months after an episode of sepsis with peritonitis. The compound heterozygous mutations p.Gly221Ser and c.653C>T in STAR were identified by targeted gene-panel sequencing. Skin hyperpigmentation should be considered an important clue for diagnosing NCCLAH.

A female with typical fragile-X phenotype caused by maternal isodisomy of the entire X chromosome.

Fragile X syndrome (FXS) is the most common inherited cause of intellectual disability, especially in males. Females with FXS tend to be relatively mildly affected because of compensation by a second X chromosome with a normal FMR1 gene. In most cases, FXS is caused by an expansion of the CGG repeats (>200 triplets, full mutation, FM) in the 5'-untranslated region of the FMR1 gene. Premutation alleles (PM, 55-200 repeats), usually lack the clinical features of FXS, are highly unstable when transmitted to offspring and can give rise to FM, especially in female meiosis. We describe a 3-year-old girl with typical FXS, with only a fully expanded FMR1 allele (288 CGG repeats) due to uniparental isodisomy of X chromosome, inherited from mother carrying a premutation allele. The patient's FMR1 methylation region is completely methylated due to full mutation of CGG repeat. This unusual and rare case indicates the importance of a detailed genomic approach to explain nontraditional Mendelian inheritance pattern.

Bromide and iodide selectivity in membrane capacitive deionisation, and its potential application to reduce the formation of disinfection by-products in water treatment.

The formation of toxic disinfection by-products during water disinfection due to the presence of bromide and iodide is a major concern. Current treatment technologies such as membrane, adsorption and electrochemical processes have been known to have limitations such as high energy demand and excessive chemical use. In this study, the selectivity between bromide and iodide, and their removal in membrane capacitive deionisation (MCDI) was evaluated. The results showed that iodide was more selectively removed over bromide from several binary feed waters containing bromide and iodide under various initial concentrations and applied voltages. Even in the presence of significant background concentration of sodium chloride, definite selectivity of iodide over bromide was observed. The high partial-charge transfer coefficient of iodide compared to bromide could be a feasible explanation for high iodide selectivity since both bromide and iodide have similar ionic charge and hydrated radius. The result also shows that MCDI can be a potential alternative for the removal of bromide and iodide during water treatment.

Behavior Modeling for Charge Storage in Single-Poly Floating Gate Device.

Single-poly floating gate is an efficient device for charge storage due to low power program, and implemented in a standard CMOS process. In floating gate, charges are injected and removed through the thin gate oxide. Among the gate leakage current mechanisms, FN tunneling is significant in the high electric field, while PF emission in the low electric field. We extracted FN and PF components from the measured current and built an accurate model which include fringing field effect induced by the 3-dimensional structure. This model helps engineers reflect exact behaviors of charge storage device in their circuit design.

Diagnostic challenge for the rare lysosomal storage disease: Late infantile GM1 gangliosidosis.

BACKGROUND: GM1 gangliosidosis is a rare lysosomal storage disorder caused by GLB1 mutations. Because of its extreme rarity and symptoms that overlap with other neurodegenerative diseases, its diagnosis is sometimes challenging, especially in the late infantile form with less severe phenotype. We aim to expand the clinical and genetic spectrum of late infantile GM1 gangliosidosis. METHODS: We confirmed a diagnosis of GM1 gangliosidosis based on GLB1 mutations and/or the deficiency of ß-galactosidase activity. We identified the first two cases by whole-exome sequencing, and then the other six cases by direct sequencing of GLB1 with enzyme analysis. RESULTS: All eight patients presented with developmental delay or regression during late infancy and later developed epilepsy, mostly intractable generalized tonic seizures. No clinical signs of storage disorders were noted except for skeletal abnormalities. Interestingly, we found aspartate transaminase (AST) elevations alone with normal alanine transaminase (ALT) levels in all patients. The recurrent mutation, p.D448V in GLB1, accounted for 50.0% of total alleles in our cohort. CONCLUSIONS: With a high index of clinical suspicion, skeletal survey and AST level would be important for early diagnosis of GM1 gangliosidosis. In addition, we would highlight the clinical usefulness of whole-exome sequencing in the diagnosis of non-classical presentation of ultra-rare neurodegenerative disease in children.

Network analysis reveals increased integration during emotional and motivational processing.

In recent years, a large number of human studies have investigated large-scale network properties of the brain, typically during the resting state. A critical gap in the knowledge base concerns the understanding of network properties of a focused set of brain regions during task conditions engaging these regions. Although emotion and motivation recruit many brain regions, it is currently unknown how they affect network-level properties of inter-region interactions. In the present study, we sought to characterize network structure during "mini-states" engendered by emotional and motivational cues investigated in separate studies. To do so, we used graph-theoretic network analysis to probe network-, community-, and node-level properties of the trial-by-trial functional connectivity between regions of interest. We used methods that operate on weighted graphs that make use of the continuous information of connectivity strength. In both the emotion and motivation datasets, global efficiency increased and decomposability decreased. Thus, processing became less segregated with the context signaled by the cue (potential shock or potential reward). Our findings also revealed several important features of inter-community communication, including notable contributions of the bed nucleus of the stria terminalis, anterior insula, and thalamus during threat and of the caudate and nucleus accumbens during reward. Together, the results suggest that one way in which emotional and motivational processing affect brain responses is by enhancing signal communication between regions, especially between cortical and subcortical ones.

Biomimetic variable-focus lens system controlled by winding-type SMA actuator.

Inspired by the biomechanics of the human eye, which includes a crystalline lens, ciliary muscles, and zonular fibers, the proposed variablefocus lens system consists of a PDMS lens, winding-type SMA actuator, and load arms. The PDMS lens is encircled and stretched by the load arms joined to an outer ring that is rotated by the winding-type SMA actuator, thereby changing the focal length of the lens. In contrast to other single tunable-focus lenses, the proposed system uses a gel-type PDMS lens, which is insensitive to gravity and external vibration, and can be made into a biconvex or aspheric shape. The design of the proposed system is described in detail, and experimental results demonstrate the validity of the proposed system.

Altered pharmacokinetics and hepatic uptake of TBuMA in ethynylestradiol-induced cholestasis.

The objective of this study was to examine the pharmacokinetics of organic cations in intrahepatic cholestatic rats. A pretreatment with 17alpha-ethynylestradiol was used to induce intrahepatic cholestasis, and tributylmethylammonium (TBuMA) was used as a representative model organic cation. When [3H]TBuMA was intravenously administered1 the AUC value for TBuMA was significantly increased by 79% in cholestasis, and its total systemic clearance was consequently decreased by 46%. In addition, the in vivo hepatic uptake clearance of TBuMA from the plasma to the liver was decreased by 50% in cholestasis. The concentration of bile salts in plasma was increased by 2.1 fold in cholestatic rats. Since TBuMA forms ion-pair complexes with anionic components such as bile salts, the decreased hepatic uptake of TBuMA in cholestasis may be due to a change in endogenous components, e.g., bile salts in the plasma. In isolated normal hepatocytes, the uptake clearance for TBuMA in the presence of cholestatic plasma was decreased by 20% compared with normal plasma. Therefore, we conclude that the inhibition of the hepatic uptake process by the cholestasis may be in part due to the increased formation of ion-pair complexes of TBuMA with bile salts in the plasma.