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DNAJC12 deficiency is a recently described inherited metabolic disorder resulting in hyperphenylalaninemia and neurotransmitter deficiency. The effect of treatment on the prevention of neurological manifestations in this newly reported and heterogenous disorder is not fully understood, and the optimal treatment strategy remains to be elucidated. The global or regional incidence of the disease is yet to be estimated. Here, we report the first individual diagnosed with DNAJC12 deficiency in Hong Kong; the condition was picked up by newborn screening due to hyperphenylalaninemia after ruling out phenylalanine hydroxylase deficiency and other tetrahydrobiopterin related disorders. Compound heterozygous variants in the DNAJC12 gene were identified, which included a novel missense change and a nonsense pathogenic variant. Treatment with neurotransmitter precursors (tetrahydrobiopterin, levodopa, and oxitriptan) was initiated at four months of age, and dietary protein restriction was started at four years and six months of age. He remains asymptomatic at four and a half years of age, apart from having mildly impaired socio-communication and language development. In this report, we discuss the current diagnostic approach to hyperphenylalaninemia in newborn screening and the uncertainties that exist in the clinical outcome from earlier detection, treatment, and monitoring of DNAJC12-deficiency patients.

We report a child with biallelic COQ6 variants presenting with familial thrombotic microangiopathy (TMA). A Chinese boy presented with steroid-resistant nephrotic syndrome at 8 months old and went into kidney failure requiring peritoneal dialysis at 15 months old. He presented with hypertensive encephalopathy with the triad of microangiopathic haemolytic anaemia, thrombocytopenia, and acute on chronic kidney injury at 25 months old following a viral illness. Kidney biopsy showed features of chronic TMA. He was managed with supportive therapy and plasma exchanges and maintained on eculizumab. However, he had another TMA relapse despite complement inhibition a year later. Eculizumab was withdrawn, and supportive therapies, including ubiquinol (50 mg/kg/day) and vitamins, were optimized. He remained relapse-free since then for 4 years. Of note, his elder sister succumbed to multiple organ failure with histological evidence of chronic TMA at the age of 4. Retrospective genetic analysis revealed the same compound heterozygous variants in the COQ6 gene., Competing Interests: Declarations. Consent to participate: The authors declare that they have obtained consent from the patient discussed in the report. Conflict of interest: All the authors declared no competing interests., (© 2024. The Author(s), under exclusive licence to International Pediatric Nephrology Association.)

Background: Newborn screening programmes offer an opportunity to obtain dried blood spots (DBS) cards that contain a wealth of biological information that can be stored for long periods and have potential benefits for research and quality assurance. However, the storage and secondary uses of DBS cards pose numerous ethical, clinical, and social challenges. Empirical research exploring public attitudes is central to public policy planning as it can indicate whether or not there is broad public support, define public concerns, and ascertain the circumstances required to alleviate concerns and ensure support. This study aims to describe the clinical experience and attitudes towards newborn screening and investigate the perceptions and expectations of Hong Kong parents and healthcare providers regarding the retention of DBS cards and their usage for research., Methods: We conducted semi-structured in-person interviews with 20 parents and healthcare providers in Hong Kong. Thematic analysis was conducted., Results: Awareness of the significant research value of secondary uses of dried blood spot cards is low. Parents and healthcare providers support the storage and secondary uses of DBS cards with some concerns, including privacy and confidentiality breaches, the risk of discrimination or stigmatisation based on genetic information, and their inability to oversee the use of their child's biospecimen. Parents, however, prioritise their child's health over privacy concerns and support identifiable storage using pseudonymity to gain more information about their children's health., Conclusion: Child information takes precedence over potential concerns over privacy, underscoring the significance of engaging patients and the public in shaping public policy related to biobanking and healthcare research, in line with cultural and social values., (© 2024. The Author(s).)

Vestimentiferan tubeworms that thrive in deep-sea chemosynthetic ecosystems rely on a single species of sulfide-oxidizing gammaproteobacterial endosymbionts housed in a specialized symbiotic organ called trophosome as their primary carbon source. While this simple symbiosis is remarkably productive, the host-symbiont molecular interactions remain unelucidated. Here, we applied an approach for deep-sea in situ single-cell fixation in a cold-seep tubeworm, Paraescarpia echinospica . Single-cell RNA sequencing analysis and further molecular characterizations of both the trophosome and endosymbiont indicate that the tubeworm maintains two distinct metabolic "microniches" in the trophosome by controlling the availability of chemosynthetic gases and metabolites, resulting in oxygenated and hypoxic conditions. The endosymbionts in the oxygenated niche actively conduct autotrophic carbon fixation and are digested for nutrients, while those in the hypoxic niche conduct anaerobic denitrification, which helps the host remove ammonia waste. Our study provides insights into the molecular interactions between animals and their symbiotic microbes.

The objective of the study is to evaluate the evolving phenotype and genetic spectrum of patients with succinic semialdehyde dehydrogenase deficiency (SSADHD) in long-term follow-up. Longitudinal clinical and biochemical data of 22 pediatric and 9 adult individuals with SSADHD from the patient registry of the International Working Group on Neurotransmitter related Disorders (iNTD) were studied with in silico analyses, pathogenicity scores and molecular modeling of ALDH5A1 variants. Leading initial symptoms, with onset in infancy, were developmental delay and hypotonia. Year of birth and specific initial symptoms influenced the diagnostic delay. Clinical phenotype of 26 individuals (median 12 years, range 1.8-33.4 years) showed a diversifying course in follow-up: 77% behavioral problems, 76% coordination problems, 73% speech disorders, 58% epileptic seizures and 40% movement disorders. After ataxia, dystonia (19%), chorea (11%) and hypokinesia (15%) were the most frequent movement disorders. Involvement of the dentate nucleus in brain imaging was observed together with movement disorders or coordination problems. Short attention span (78.6%) and distractibility (71.4%) were the most frequently behavior traits mentioned by parents while impulsiveness, problems communicating wishes or needs and compulsive behavior were addressed as strongly interfering with family life. Treatment was mainly aimed to control epileptic seizures and psychiatric symptoms. Four new pathogenic variants were identified. In silico scoring system, protein activity and pathogenicity score revealed a high correlation. A genotype/phenotype correlation was not observed, even in siblings. This study presents the diversifying characteristics of disease phenotype during the disease course, highlighting movement disorders, widens the knowledge on the genotypic spectrum of SSADHD and emphasizes a reliable application of in silico approaches., (© 2024 The Authors. Journal of Inherited Metabolic Disease published by John Wiley & Sons Ltd on behalf of SSIEM.)

Killer whales ( Orcinus orca ) are currently recognized as a single ecologically and morphologically diverse, globally distributed species. Multiple morphotypes or ecotypes have been described, often associated with feeding specialization, and several studies have suggested taxonomic revision to include multiple subspecies or species in the genus. We review the ecological, morphological and genetic data for the well-studied 'resident' and Bigg's (aka 'transient') ecotypes in the eastern North Pacific and use quantitative taxonomic guidelines and standards to determine whether the taxonomic status of these killer whale ecotypes should be revised. Our review and new analyses indicate that species-level status is justified in both cases, and we conclude that eastern North Pacific Bigg's killer whales should be recognized as Orcinus rectipinnus (Cope in Scammon, 1869) and resident killer whales should be recognized as Orcinus ater (Cope in Scammon, 1869)., Competing Interests: We declare we have no competing interests., (© 2024 The Authors.)

Newborn screening (NBS) is an important public health program that aims to identify pre-symptomatic healthy babies that will develop significant disease if left undiagnosed and untreated. The number of conditions being screened globally is expanding rapidly in parallel with advances in technology, diagnosis, and treatment availability for these conditions. In Hong Kong, NBS for inborn errors of metabolism (NBSIEM) began as a pilot program in October 2015 and was implemented to all birthing hospitals within the public healthcare system in phases, with completion in October 2020. The number of conditions screened for increased from 21 to 24 in April 2016 and then to 26 in October 2019. The overall recruitment rate of the NBS program was 99.5%. In the period between October 2015 and December 2022, 125,688 newborns were screened and 295 were referred back for abnormal results. The recall rate was reduced from 0.26% to 0.12% after the implementation of second-tier testing. An inherited metabolic disorder (IMD) was eventually confirmed in 47 infants, making the prevalence of IMD in Hong Kong 1 in 2674. At the time of the NBS result, 78.7% of the newborns with IMD were asymptomatic. There were two deaths reported: one newborn with methylmalonic acidemia cobalamin B type (MMACblB) died after the initial crisis and another case of carnitine palmitoyltransferase II deficiency (CPTII) died at 18 months of age after metabolic decompensation. The most common IMD noted were disorders of fatty acid oxidation metabolism (40%, 19 cases), closely followed by disorders of amino acid metabolism (38%, 18 cases), with carnitine uptake defect (19.1%, 9 cases) and citrullinemia type II (17%, 8 cases) being the two most common IMD picked up by the NBSIEM in Hong Kong. Out of the all the IMDs identified, 19.1% belonged to diverse ethnic groups. False negative cases were reported for citrullinemia type II and congenital adrenal hyperplasia during this period.

In this study, we evaluated the implementation of a second-tier genetic screening test using an amplicon-based next-generation sequencing (NGS) panel in our laboratory during the period of 1 September 2021 to 31 August 2022 for the newborn screening (NBS) of six conditions for inborn errors of metabolism: citrullinemia type II (MIM #605814), systemic primary carnitine deficiency (MIM #212140), glutaric acidemia type I (MIM #231670), beta-ketothiolase deficiency (#203750), holocarboxylase synthetase deficiency (MIM #253270) and 3-hydroxy-3-methylglutaryl-CoA lyase deficiency (MIM # 246450). The custom-designed NGS panel can detect sequence variants in the relevant genes and also specifically screen for the presence of the hotspot variant IVS16ins3kb of SLC25A13 by the copy number variant calling algorithm. Genetic second-tier tests were performed for 1.8% of a total of 22,883 NBS samples. The false positive rate for these six conditions after the NGS second-tier test was only 0.017%, and two cases of citrullinemia type II would have been missed as false negatives if only biochemical first-tier testing was performed. The confirmed true positive cases were citrullinemia type II ( n = 2) and systemic primary carnitine deficiency ( n = 1). The false positives were later confirmed to be carrier of citrullinemia type II ( n = 2), carrier of glutaric acidemia type I ( n = 1) and carrier of systemic primary carnitine deficiency ( n = 1). There were no false negatives reported. The incorporation of a second-tier genetic screening test by NGS greatly enhanced our program's performance with 5-working days turn-around time maintained as before. In addition, early genetic information is available at the time of recall to facilitate better clinical management and genetic counseling.

Objective: To compare and contrast the perceived care needs of children with life-limiting conditions (CLLC) from the perspectives of the children, parents and healthcare providers., Design: A qualitative case study method using semistructured interviews was employed with a within-case and across-case analysis. Themes and subthemes emerging from the cases were compared and contrasted in the across-case analysis to explore the similarities and variations in participant perceptions., Setting/participants: The setting was the paediatric departments of five regional hospitals in Hong Kong. Twenty-five sets of informants (CLLC-parent-healthcare provider) were recruited, with 65 individual interviews conducted., Results: A total of 3784 units of analysis were identified, resulting in three themes with subthemes. 'Living with the disease' (55.8%) occupied the largest proportion, followed by 'information and understanding about the disease' (27.4%), and 'care support and palliative care' (16.8%). Healthcare provider support mainly focused on physical concerns. Family and social support were present, but carer stress created tension between couples. Doctors were the primary source of medical information, but the parents had to seek further information via the internet and support from patient groups. There was a perceived need for better coordination and collaboration of care. The palliative care approach coordinated by nurses was seen as helpful in addressing the care needs of the CLLC., Conclusions: This original study identified the importance of palliative care with active engagement of parents which can address the service gap for CLLC., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

The dissolution of anthropogenic carbon dioxide (CO 2 ) in seawater has altered its carbonate chemistry in the process of ocean acidification (OA). OA affects the viability of marine species. In particular, calcifying organisms and their early planktonic larval stages are considered vulnerable. These organisms often utilize energy reserves for metabolism rather than growth and calcification as supported by bulk RNA-sequencing (RNA-seq) experiments. Yet, transcriptomic profiling of a bulk sample reflects the average gene expression of the population, neglecting the variations between individuals, which forms the basis for natural selection. Here, we used single-embryo RNA-seq on larval sea urchin Heliocidaris crassispina, which is a commercially and ecologically valuable species in East Asia, to document gene expression changes to OA at an individual and family level. Three paternal half-sibs groups were fertilized and exposed to 3 pH conditions (ambient pH 8.0, 7.7 and 7.4) for 12 h prior to sequencing and oxygen consumption assay. The resulting transcriptomic profile of all embryos can be distinguished into four clusters, with differences in gene expressions that govern biomineralization, cell differentiation and patterning, as well as metabolism. While these responses were influenced by pH conditions, the male identities also had an effect. Specifically, a regression model and goodness of fit tests indicated a significant interaction between sire and pH on the probability of embryo membership in different clusters of gene expression. The single-embryo RNA-seq approach is promising in climate stressor research because not only does it highlight potential impacts before phenotypic changes were observed, but it also highlights variations between individuals and lineages, thus enabling a better determination of evolutionary potential., (© 2023 The Authors. Molecular Ecology published by John Wiley & Sons Ltd.)

Dried blood spot (DBS) cards from newborn screening (NBS) programs represent a wealth of biological data. They can be stored easily for a long time, have the potential to support medical and public health research, and have secondary usages such as quality assurance and forensics, making it the ideal candidate for bio-banking. However, worldwide policies vary with regard to the duration of storage of DBS cards and how it can be used. Recent advances in genomics have also made it possible to perform extended genetic testing on DBS cards in the newborn period to diagnose both actionable and non-actionable childhood and adult diseases. Both storage and secondary uses of DBS cards raise many ethical, clinical, and social questions. The openness of the key stakeholders, namely, parents and healthcare providers (HCPs), to store the DBS cards, and for what duration and purposes, and to extended genetic testing is largely dependent on local cultural-social-specific factors. The study objective is to assess the parents' and HCPs' awareness and receptivity toward DBS retention, its secondary usage, and extended genetic testing. A cross-sectional, self-administrated survey was adopted at three hospitals, out of which two were public hospitals with maternity services, between June and December 2022. In total, 452 parents and 107 HCPs completed and returned the survey. Overall, both HCPs and parents were largely knowledgeable about the potential benefits of DBS card storage for a prolonged period and its secondary uses, and they supported extended genetic testing. Knowledge gaps were found in respondents with a lower education level who did not know that a DBS card could be stored for an extended period ( p < 0.001), could support scientific research ( p = 0.033), and could aid public health research, and future policy implementation ( p = 0.030). Main concerns with regard to DBS card storage related to potential privacy breaches and anonymity (Parents 70%, HCPs 60%). More parents, compared to HCPs, believed that storing DBS cards for secondary research does not lead to a reciprocal benefit to the child ( p < 0.005). Regarding extended genetic testing, both groups were receptive and wanted to know about actionable childhood- and adult-onset diseases. More parents (four-fifths) rather than HCPs (three-fifths) were interested in learning about a variant with unknown significance ( p < 0.001). Our findings report positive support from both parents and HCPs toward the extended retention of DBS cards for secondary usage and for extended genetic testing. However, more efforts to raise awareness need to be undertaken in addition to addressing the ethical concerns of both parents and HCPs to pave the way forward toward policy-making for DBS bio-banking and extended genetic testing in Hong Kong.

Coenzyme Q 10 (CoQ 10 ) is an endogenously synthesized lipid molecule. It is best known for its role as a cofactor within the mitochondrial respiratory chain where it functions in electron transfer and ATP synthesis. However, there are many other cellular pathways that also depend on the CoQ 10 supply (redox homeostasis, ferroptosis and sulfide oxidation). The CoQ 10 biosynthesis pathway consists of several enzymes, which are encoded by the nuclear DNA. The majority of these enzymes are responsible for modifications of the CoQ-head group (benzoquinone ring). Only three enzymes (PDSS1, PDSS2 and COQ2) are required for assembly and attachment of the polyisoprenoid side chain. The head-modifying enzymes may assemble into resolvable domains, representing COQ complexes. During the last two decades, numerous inborn errors in CoQ 10 biosynthesis enzymes have been identified. Thus far, 11 disease genes are known ( PDSS1 , PDSS2 , COQ2 , COQ4 , COQ5 , COQ6 , COQ7 , COQ8A , COQ8B , COQ9 and HPDL ). Disease onset is highly variable and ranges from the neonatal period to late adulthood. CoQ 10 deficiency exerts detrimental effects on the nervous system. Potential consequences are neuronal death, neuroinflammation and cerebral gliosis. Clinical features include encephalopathy, regression, movement disorders, epilepsy and intellectual disability. Brain magnetic resonance imaging (MRI) is the most important tool for diagnostic evaluation of neurological damage in individuals with CoQ 10 deficiency. However, due to the rarity of the different gene defects, information on disease manifestations within the central nervous system is scarce. This review aims to provide an overview of brain MRI patterns observed in primary CoQ 10 biosynthesis disorders and to highlight disease-specific findings.

Objective: To determine the prevalence of mitochondrial diseases (MD) in Hong Kong (HK) and to evaluate the clinical characteristics and genetic landscape of MD patients in the region., Methods: This study retrospectively reviewed the phenotypic and molecular characteristics of MD patients from participating public hospitals in HK between January 1985 to October 2020. Molecularly and/or enzymatically confirmed MD cases of any age were recruited via the Clinical Analysis and Reporting System (CDARS) using relevant keywords and/or International Classification of Disease (ICD) codes under the HK Hospital Authority or through the personal recollection of treating clinicians among the investigators., Results: A total of 119 MD patients were recruited and analyzed in the study. The point prevalence of MD in HK was 1.02 in 100,000 people (95% confidence interval 0.81-1.28 in 100,000). 110 patients had molecularly proven MD and the other nine were diagnosed by OXPHOS enzymology analysis or mitochondrial DNA depletion analysis with unknown molecular basis. Pathogenic variants in the mitochondrial genome (72 patients) were more prevalent than those in the nuclear genome (38 patients) in our cohort. The most commonly involved organ system at disease onset was the neurological system, in which developmental delay, seizures or epilepsy, and stroke-like episodes were the most frequently reported presentations. The mortality rate in our cohort was 37%., Conclusion: This study is a territory-wide overview of the clinical and genetic characteristics of MD patients in a Chinese population, providing the first available prevalence rate of MD in Hong Kong. The findings of this study aim to facilitate future in-depth evaluation of MD and lay the foundation to establish a local MD registry., (© 2023. The Author(s).)

Background: Children with neurodegenerative conditions (CNDC) often suffer from severe neurodisability and high symptom burden with multisystemic involvement. However, their symptom burden and health-related quality of life (HRQOL) is not systematically documented in the literature, and there is no existing tool for such purposes. We designed our own tool for scoring of symptom burden amongst CNDCs and adopted the PedsQL generic score 4.0 to quantify the impact of overall symptom burden on children's overall HRQOL., Methods: The Symptom Profile for children with neurodegnerative condition (SProND) questionnaire was developed, which consisted of 14 questions grouped according to 5 categories, namely epilepsy, neurobehavioural, movement and mobility related, breathing and swallowing, and other daily activities. CNDCs were recruited during visits to the Comprehensive Neurometabolic / Neurodegenerative Program of the Duchess of Kent Children's Hospital and Hong Kong Children's Hospital between November 2019 and March 2020. The SProND and PedsQL 4.0 Generic Core Scales were distributed to consenting parents of CNDCs., Results: 36 CNDCs were recruited and matched with community controls. The response rate of subject and control were 99.5% and 98.7% respectively. The Cronbach alpha was 0.61 for the neurobehavioural domain and >  = 0.7 for other domains. The greater number of symptoms each subject experiences, the worse his/ her PedsQL scores. Subjects displaying hypersalivation and swallowing difficulties had average physical health summary scores of less than 30% compared with subjects without these symptoms. On the other hand, average psychosocial health summary scores of subjects with involuntary movements, joint stiffness, hypersalivation, sleep problem and anorexia were approximately 70% compared to subjects without these symptoms., Discussion and Conclusion: This is one of the first studies to look at CNDCs as a group. We propose the SProND questionnaire for evaluation of symptom profile amongst CNDCs with satisfactory internal and external validity. It demonstrates how physical symptoms impact both physical and psychosocial HRQOL, and the cumulative effect of individual symptoms on the overall HRQOL. As such, CNDCs should be systematically screened for multi-systemic symptoms as a routine part of their clinical care, and care plans should be individually catered to individual patients' symptom burden and specific needs., (© 2022. The Author(s).)

During development, different cell types originate from a common progenitor at well-defined time points. Previous lineage-tracing of Pax7 + progenitors from the somitic mesoderm has established its developmental trajectory towards the dermis, brown adipocytes, and skeletal muscle in the dorsal trunk; yet the molecular switches and mechanisms guiding the differentiation into different lineages remain unknown. We performed lineage-tracing of Pax7-expressing cells in mouse embryos at E9.5 and profiled the transcriptomes of Pax7-progenies on E12.5, E14.5, and E16.5 at single-cell level. Analysis of single-cell transcriptomic data at multiple time points showed temporal-specific differentiation events toward muscle, dermis, and brown adipocyte, identified marker genes for putative progenitors and revealed transcription factors that could drive lineage-specific differentiation. We then utilized a combination of surface markers identified in the single-cell data, Pdgfra, Thy1, and Cd36, to enrich brown adipocytes, dermal fibroblasts, and progenitors specific for these two cell types at E14.5 and E16.5. These enriched cell populations were then used for further culture and functional assays in vitro, in which Wnt5a and Rgcc are shown to be important factors that could alter lineage decisions during embryogenesis. Notably, we found a bipotent progenitor population at E14.5, having lineage potentials towards both dermal fibroblasts and brown adipocytes. They were termed eFAPs (embryonic fibro/adipogenic progenitors) as they functionally resemble adult fibro/adipogenic progenitors. Overall, this study provides further understanding of the Pax7 lineage during embryonic development using a combination of lineage tracing with temporally sampled single-cell transcriptomics., (© 2022. The Author(s).)

In addition to coordinating the storage and mobilization of neutral fat, lipid droplets (LDs) are conserved organelles that can accommodate additional cargos in order to support animal development. However, it is unclear if each type of cargo is matched with a specific subset of LDs. Here, we report that SEIP-1/seipin defines a subset of oocyte LDs that are required for proper eggshell formation in C. elegans . Using a photoconvertible fluorescent protein-based imaging assay, we found that SEIP-1 positive LDs were selectively depleted after fertilization, coincident of the formation of a lipid-rich permeability barrier of the eggshell. Loss of SEIP-1 function caused impenetrant embryonic arrest, which could be worsened by FAT-3/fatty acyl-CoA desaturase deficiency or suppressed by PLIN-1/Perilipin deficiency. The embryonic development of seip-1; plin-1 mutant in turn depended on the recruitment of RAB-18/Rab18 to LDs, which was not observed in wild type embryos. We propose that SEIP-1 dependent and independent mechanisms act in parallel to ensure the packaging and export of lipid-rich permeability barrier constituents, which involve LDs. The identity of these LDs, as defined by their associated proteins, exhibits unexpected plasticity that ultimately ensures the survival of embryos ex utero ., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Cao, Fung and Mak.)

Aim: Childhood encephalopathy comprises a wide range of etiologies with distinctive distribution in different age groups. We reviewed the pattern of encephalopathy admitted to the pediatric intensive care unit (PICU) of a tertiary children's hospital., Methods: We reviewed the medical records and reported the etiologies, clinical features, and outcomes of children with encephalopathy., Results: Twenty-four admissions to the PICU between April 2019 and May 2020 were reviewed. The median (interquartile range) age was 10.0 (14.7) years and 62.5% were boys. Confusion (66.7%) was the most common presentation. Adverse effects related to medications (33.3%) and metabolic disease (20.8%) were predominant causes of encephalopathies in our study cohort. Methotrexate was responsible for most of the medication-associated encephalopathy (37.5%), whereas Leigh syndrome, pyruvate dehydrogenase deficiency and Wernicke's encephalopathy accounted for those with metabolic disease. The median Glasgow Coma Scale (GCS) on admission was 12.5 (9.0). Antimicrobials (95.8%) and antiepileptic drugs (60.9%) were the most frequently given treatment. Children aged 2 years or younger were all boys (P = 0.022) and had a higher proportion of primary metabolic disease (P = 0.04). Intoxication or drug reaction only occurred in older children. The mortality was 8.3%, and over half of the survivors had residual neurological disability upon PICU discharge. Primary metabolic disease (P = 0.002), mechanical ventilation (P = 0.019), failure to regain GCS back to baseline level (P = 0.009), and abnormal cognitive function on admission (P = 0.03) were associated with cerebral function impairment on PICU discharge., Conclusions: Primary metabolic encephalopathy was prevalent in younger children, whereas drug-induced toxic encephalopathy was common among older oncology patients. Survivors have significant neurologic morbidity. Failure to regain baseline GCS was a poor prognostic factor for neurological outcomes., Competing Interests: Disclosure: The authors declare no conflict of interest., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Objective: Dravet syndrome (DS) is a severe and intractable form of epilepsy with prolonged seizures which may evolve to other seizure types and associated with mild-to-severe intellectual disabilities. Fibroblast growth factor 21 (FGF-21) is a stress hormone mediating metabolic and oxidative stress and circulating level of FGF-21 had been shown to increase in some patients with impairment of oxidative phosphorylation in muscles. In DS, FGF-21 is of interest for further study as mitochondrial oxidative stress was identified previously in patients., Methods: Plasma FGF-21 levels were compared between 22 DS patients and 22 normal controls, and their clinical characteristics of DS patients at the time of plasma sampling were studied retrospectively. Besides, the relationships of FGF-21 level with intellectual development, seizure frequency, valproate treatment, and types of SCN1A mutations were analyzed. Logarithmic transformation of FGF-21 levels was performed before comparison and statistical analysis., Results: Mean of log 10 FGF-21 level was significantly higher in DS patients when comparing with normal controls (P = .0042). Mean of log 10 FGF-21 level was significantly higher in DS patients with normal-to-mild ID versus mild-to-severe ID (P = .0193) and with valproate treatment versus without valproate treatment (P = .015). No significant difference was shown in FGF-21 level in DS patients with missense versus truncating SCN1A variants, and no correlation could be demonstrated between seizure frequency and FGF-21 level., Significance: Significantly higher level of plasma FGF-21 was identified in DS patients. The high FGF-21 levels were shown to be associated with developmental outcome and valproate treatment. These results support further investigation on the relationship of FGF-21 with the clinical outcomes of DS and other related mechanism which is important for possible therapeutic development for this epileptic encephalopathy., (© 2021 The Authors. Epilepsia Open published by Wiley Periodicals LLC on behalf of International League Against Epilepsy.)

Inherited disorders of neurotransmitter metabolism are a group of rare diseases, which are caused by impaired synthesis, transport, or degradation of neurotransmitters or cofactors and result in various degrees of delayed or impaired psychomotor development. To assess the effect of neurotransmitter deficiencies on intelligence, quality of life, and behavior, the data of 148 patients in the registry of the International Working Group on Neurotransmitter Related Disorders (iNTD) was evaluated using results from standardized age-adjusted tests and questionnaires. Patients with a primary disorder of monoamine metabolism had lower IQ scores (mean IQ 58, range 40-100) within the range of cognitive impairment (<70) compared to patients with a BH 4 deficiency (mean IQ 84, range 40-129). Short attention span and distractibility were most frequently mentioned by parents, while patients reported most frequently anxiety and distractibility when asked for behavioral traits. In individuals with succinic semialdehyde dehydrogenase deficiency, self-stimulatory behaviors were commonly reported by parents, whereas in patients with dopamine transporter deficiency, DNAJC12 deficiency, and monoamine oxidase A deficiency, self-injurious or mutilating behaviors have commonly been observed. Phobic fears were increased in patients with 6-pyruvoyltetrahydropterin synthase deficiency, while individuals with sepiapterin reductase deficiency frequently experienced communication and sleep difficulties. Patients with BH 4 deficiencies achieved significantly higher quality of life as compared to other groups. This analysis of the iNTD registry data highlights: (a) difference in IQ and subdomains of quality of life between BH 4 deficiencies and primary neurotransmitter-related disorders and (b) previously underreported behavioral traits., (© 2021 The Authors. Journal of Inherited Metabolic Disease published by John Wiley & Sons Ltd on behalf of SSIEM.)

Background: Aromatic L-amino acid decarboxylase deficiency is a rare neurometabolic disease due to impaired decarboxylation of neurotransmitter precursors to its active form., Case: We retrospectively reviewed 8 cases from 2008 to 2019 with cerebrospinal fluid neurotransmitter analysis performed at our centre. All cases had an elevated urine vanillactic acid and, in most cases, with N-acetylvanilalanine detected. Cerebrospinal fluid analysis showed low downstream metabolites vanillylmandelic acid, homovanillic acid but high 3-O-methyl-L-DOPA, 5-hydroxytryptophan. Cerebrospinal fluid pterins were normal. Genotyping in DDC confirms the diagnosis. Urine organic acid analysis provided the first clue to diagnosis in four of the cases, which then triggered cerebrospinal fluid neurotransmitter and genetic analysis. We also developed a diagnostic decision support system to assist the interpretation of the mass spectrometry data from urine organic acids., Conclusions: Urine organic acid could be essential in guiding subsequent investigations for the diagnosis of aromatic L-amino acid decarboxylase deficiency. We propose to screen suspected cases first with urine organic acids, specifically looking for vanillactic acid and N-acetylvanilalanine. Suggestive findings should be followed with target analysis for c.714 + 4A > T in ethnically Chinese patients. The assistive tool allowed expedite interpretation of profile data generated from urine organic acids analysis. It may also reduce interpreter's bias when peaks of interest are minor peaks in the spectrum., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Background: Movement disorders are a group of heterogeneous neurological diseases including hyperkinetic disorders with unwanted excess movements and hypokinetic disorders with reduction in the degree of movements. The objective of our study is to investigate the genetic etiology of a cohort of paediatric patients with movement disorders by whole exome sequencing and to review the potential treatment implications after a genetic diagnosis., Results: We studied a cohort of 31 patients who have paediatric-onset movement disorders with unrevealing etiologies. Whole exome sequencing was performed and rare variants were interrogated for pathogenicity. Genetic diagnoses have been confirmed in 10 patients with disease-causing variants in CTNNB1, SPAST, ATP1A3, PURA, SLC2A1, KMT2B, ACTB, GNAO1 and SPG11. 80% (8/10) of patients with genetic diagnosis have potential treatment implications and treatments have been offered to them. One patient with KMT2B dystonia showed clinical improvement with decrease in dystonia after receiving globus pallidus interna deep brain stimulation., Conclusions: A diagnostic yield of 32% (10/31) was reported in our cohort and this allows a better prediction of prognosis and contributes to a more effective clinical management. The study highlights the potential of implementing precision medicine in the patients.

Tau pathology in Alzheimer's disease (AD) first develops in the entorhinal cortex (EC), then spreads to the hippocampus, followed by the neocortex. Overall, tau pathology correlates well with neurodegeneration and cell loss, but the spatial and temporal association between tau pathology and overt volume loss (atrophy) associated with structural changes or cell loss is unclear. Using in vivo magnetic resonance imaging (MRI) with tensor-based morphometry (TBM), we mapped the spatiotemporal pattern of structural changes in a mouse model of AD-like progressive tauopathy. A novel, coregistered in vivo MRI atlas was then applied to identify regions in the medial temporal lobe that had a significant volume reduction. Our study shows that in a mouse model of tauopathy spread, the propagation of tau pathology from the EC to the hippocampus is associated with TBM-related atrophy, but atrophy in the dentate gyrus and subiculum precedes overt cell loss., (Copyright © 2020 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. Distributed under a Creative Commons Attribution NonCommercial License 4.0 (CC BY-NC).)

Background: Mitochondrial diseases (MDs) are a group of clinically and genetically heterogeneous disorders characterized by defects in oxidative phosphorylation. Since clinical phenotypes of MDs may be non-specific, genetic diagnosis is crucial for guiding disease management. In the current study, whole-exome sequencing (WES) was performed for our paediatric-onset MD cohort of a Southern Chinese origin, with the aim of identifying key disease-causing variants in the Chinese patients with MDs., Methods: We recruited Chinese patients who had paediatric-onset MDs and a minimum mitochondrial disease criteria (MDC) score of 3. Patients with positive target gene or mitochondrial DNA sequencing results were excluded. WES was performed, variants with population frequency ≤ 1% were analysed for pathogenicity on the basis of the American College of Medical Genetics and Genomics guidelines., Results: Sixty-six patients with pre-biopsy MDC scores of 3-8 were recruited. The overall diagnostic yield was 35% (23/66). Eleven patients (17%) were found to have mutations in MD-related genes, with COQ4 having the highest mutation rate owing to the Chinese-specific founder mutation (4/66, 6%). Twelve patients (12/66, 18%) had mutations in non-MD-related genes: ATP1A3 (n = 3, two were siblings), ALDH5A1, ARX, FA2H, KCNT1, LDHD, NEFL, NKX2-2, TBCK, and WAC., Conclusions: We confirmed that the COQ4:c.370G>A, p.(Gly124Ser) variant, was a founder mutation among the Southern Chinese population. Screening for this mutation should therefore be considered while diagnosing Chinese patients suspected to have MDs. Furthermore, WES has proven to be useful in detecting variants in patients suspected to have MDs because it helps to obtain an unbiased and precise genetic diagnosis for these diseases, which are genetically heterogeneous.

Background: Rapid whole-exome sequencing (rWES) offers the potential for early diagnosis-predicated precision medicine. Previous evidence focused predominantly on infants from the intensive care unit (ICU). This study sought to examine the diagnostic and clinical utility, and the economic impact on clinical management of rWES in patients beyond infancy and ICU setting., Methods: rWES was performed on a prospective cohort of patients with suspected monogenic disorder referred from territory-wide paediatric ICUs and non-ICUs in Hong Kong urging for rapid genetic diagnosis. All eligible families were invited. We aimed to achieve a rapid turnaround time (TAT) of 14 days. Clinical utility and costs associated with clinical management were assessed in diagnosed cases. Actual quantitative changes in healthcare utilisation were compared with a counterfactual diagnostic trajectory and/or with matched historical control whenever possible., Findings: rWES were offered to 102 families and 32/102 (31%) patients received a molecular diagnosis, with a median TAT of 11 days. Clinical management changed in 28 of 32 diagnosed patients (88%), including but not limited to modifications in treatment, avoidance of surgeries, and informing decisions on redirection of care. Cost analysis was performed in eight patients. rWES was estimated to reduce hospital length of stay by 566 days and decrease healthcare costs by HKD$8,044,250 (GBP£796,460) for these eight patients. The net cost-savings after inclusion of rWES costs were estimated to be HKD$5,325,187 (GBP£527,246)., Interpretation: This study replicates the diagnostic capacity and rapid TAT of rWES in predominantly Chinese patients, and demonstrates diagnosis-predicated precision medicine and net healthcare savings. Findings were corroborated by evidence from multinational cohorts, combined as part of a meta-analysis. rWES merits consideration as a first-tier diagnostic tool for patients with urgent needs in the clinical setting., Funding: Health and Medical Research Fund, HKU Seed Fund for Basic Research, The Society for the Relief of Disabled Children, and Edward and Yolanda Wong Fund., Competing Interests: The authors declare that they have no competing interests., (© 2020 The Authors. Published by Elsevier Ltd.)

Background: Autosomal recessive or compound heterozygous mutations in KLHL40 cause nemaline myopathy 8, which is one of the most severe forms of nemaline myopathy. The KLHL40 c.1516A>C variant has recently been reported as a founder mutation in southern Chinese., Methods: We report six cases of nemaline myopathy 8 which involves the c.1516A>C variant, from five unrelated families of non-consanguineous southern Chinese. The pre- and postnatal phenotypes of these cases were reviewed with emphasis on prenatal clinical features. Genetic testing for the founder mutation was performed on three patients with homozygous mutations., Results: Common prenatal features included reduced fetal movement, polyhydramnios, breech presentation, and clubfeet. Two pregnancies were terminated. Four live-born patients had postnatal features typical of nemaline myopathy 8. The length of survival ranged from 49 days to 17 months, with respiratory failure and infections being the principal causes of death. Haplotype analysis in three patients with homozygous mutation showed a shared haplotype block of 1.1727 cM spanning over the c.1516A>C variant, suggesting it is a southern Chinese-specific founder mutation., Conclusion: Analysis of the KLHL40 c.1516A>C variant should be considered in prenatal diagnosis of Chinese pregnant patients with suspected congenital neuromuscular disorders or with significant family history of congenital myopathies., (© 2020 The Authors. Molecular Genetics & Genomic Medicine published by Wiley Periodicals LLC.)

Although the chemistry of transition-metal complexes with carbonyl (CO) and thiocarbonyl (CS) ligands has been well developed, their heavier analogues, namely selenocarbonyl (CSe) and tellurocarbonyl (CTe) complexes remain scarce. The limited availability of such CSe and CTe complexes has so far hampered our understanding of the differences between such chalcogenocarbonyl (CE: E=O, S, Se, Te) ligands. Herein, we report the synthesis and properties of a series of cationic half-sandwich ruthenium CE complexes of the type [CpRu(CE)(H 2 IMes)(CNCH 2 Ts)][BAr F 4 ] (Cp=η 5 -C 5 H 5 - ; H 2 IMes=1,3-dimesitylimidazolin-2-ylidene; Ar F =3,5-(CF 3 ) 2 C 6 H 3 ). A combination of X-ray diffraction analyses, NMR spectroscopic analyses, and DFT calculations revealed an increasing π-accepting ability of the CE ligands in the order O

Various types of single-cell analyses are now extensively used to answer many biological questions, and with this growth in popularity, potential drawbacks to these methods are also becoming apparent. Depending on the specific application, workflows can be laborious, low throughput, and run the risk of contamination. Microfluidic designs, with their advantages of being high throughput, low in reaction volume, and compatible with bio-inert materials, have been widely used to improve single-cell workflows in all major stages of single-cell applications, from cell sorting to lysis, to sample processing and readout. Yet, designing an integrated microfluidic chip that encompasses the entire single-cell workflow from start to finish remains challenging. In this article, we review the current microfluidic approaches that cover different stages of processing in single-cell analysis and discuss the prospects and challenges of achieving a full integrated workflow to achieve total single-cell analysis in one device., (Copyright © 2020 Author(s).)

Although transition-metal complexes that contain thiocarbonyl (CS) and selenocarbonyl (CSe) ligands have been well studied, only three neutral or cationic selenonitrosyl (NSe) complexes have been reported, while anionic NSe complexes remain elusive. Herein, we report the first examples of anionic NSe-ligated ruthenium complexes, which were obtained from the reaction of anionic ruthenium nitrido complexes, elemental selenium, and 4-(N,N-dimethylamino)pyridine (DMAP). The structures of one of these ruthenium NSe complexes, as well as of the corresponding thionitrosyl (NS) and nitrosyl (NO) complexes, were systematically examined by X-ray diffraction analyses and theoretical calculations. In contrast to previous reportes, the NSe ligand in these complexes is a better π-acceptor than the NO and NS ligands and exhibits a stronger trans influence.

Background: ARX genetic defect is associated with a spectrum of neurodevelopmental disorders that exhibit a high degree of phenotypic heterogeneity., Methods: We studied a family with a 13-year old Chinese boy and his two elder brothers presented with infantile epileptic-dyskinetic encephalopathy and clarified the unknown genetic etiology of the youngest brother by whole exome sequencing., Results: The youngest brother of this family presented with developmental regression, dystonia, epilepsy, microcephaly, visual impairment and oromotor dysfunction. Hyperlactataemia, raised alanine and muscle complex IV deficiency indicated that he had mitochondrial dysfunction. Likely pathogenic hemizygous missense ARX variants (c.989G > A; p.Arg330His) located in conserved nuclear localization sequence was identified. The variant was carried by his asymptomatic mother and not found in his asymptomatic third elder brother. The intractable seizures showed complete but transient responsiveness to pyridoxal phosphate and finally controlled by valproate treatment., Conclusion: This is the first case of ARX-associated encephalopathy showing mitochondrial dysfunction and transient responsiveness to pyridoxal phosphate treatment., (Copyright © 2019 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.)

Pathogenic variants in GNB5 cause an autosomal recessive neurodevelopmental disorder with neonatal sinus bradycardia. Seizures or epilepsy occurred in 10 of 22 previously reported cases, including 6 children from one family. We delineate the epileptology of GNB5 encephalopathy. Our nine patients, including five new patients, were from seven families. Epileptic spasms were the most frequent seizure type, occurring in eight of nine patients, and began at a median age of 3 months (2 months to 3 years). Focal seizures preceded spasms in three children, with onset at 7 days, 11 days, and 4 months. One child presented with convulsive status epilepticus at 6 months. Three children had burst suppression on electroencephalography (EEG), three had hypsarrhythmia, and one evolved from burst suppression to hypsarrhythmia. Background slowing was present in all after age 3 years. Magnetic resonance imaging (MRI) showed cerebral atrophy in one child and cerebellar atrophy in another. All nine had abnormal development prior to seizure onset and ultimately had profound impairment without regression. Hypotonia was present in all, with contractures developing in two older patients. All individuals had biallelic pathogenic variants in GNB5, predicted by in silico tools to result in protein truncation and loss-of-function. GNB5 developmental and epileptic encephalopathy is characterized by epileptic spasms, focal seizures, and profound impairment., (Wiley Periodicals, Inc. © 2019 International League Against Epilepsy.)

Exogenous metabolites from microbial and dietary origins have profound effects on host metabolism. Here, we report that a sub-population of lipid droplets (LDs), which are conserved organelles for fat storage, is defined by metabolite-modulated targeting of the C. elegans seipin ortholog, SEIP-1. Loss of SEIP-1 function reduces the size of a subset of LDs while over-expression of SEIP-1 has the opposite effect. Ultrastructural analysis reveals SEIP-1 enrichment in an endoplasmic reticulum (ER) subdomain, which co-purifies with LDs. Analyses of C. elegans and bacterial genetic mutants indicate a requirement of polyunsaturated fatty acids (PUFAs) and microbial cyclopropane fatty acids (CFAs) for SEIP-1 enrichment, as confirmed by dietary supplementation experiments. In mammalian cells, heterologously expressed SEIP-1 engages nascent lipid droplets and promotes their subsequent expansion in a conserved manner. Our results suggest that microbial and polyunsaturated fatty acids serve unexpected roles in regulating cellular fat storage by promoting LD diversity.

Spinocerebellar ataxia 35 (SCA35) has been associated with pathogenic mutations in the gene TGM6. In a Chinese exome sequencing cohort, we identified 8 families with reported TGM6 variants sharing no features of SCA35. Considering this finding, we reviewed the public database gnomAD and found these variants to be significantly more common in the East Asians than in other ethnic groups (P < 0.0001). Gene constraint metrics showed that both missense and loss-of-function variants in TGM6 are likely to be tolerated and there is no regional constraint. By performing inflation analysis, it demonstrated that the cumulative frequency of TGM6 reported pathogenic variants is at least 111-fold inflated over disease prevalence of all autosomal dominant SCAs, indicating a high chance of misdiagnosis or low penetrance. Misclassification of benign or low penetrant variants as pathogenic is a significant problem that often results in genetic misdiagnosis. This highlights the necessity of evaluating variant pathogenicity with sequencing of genomes from diverse populations, both from asymptomatic controls and phenotypically different patients, in order to ensure accurate classification of variants., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Background: Intracranial germ cell tumors (GCT) are more common in Asia than in the West, accounting for about 15% of brain tumors in Asian children. The survival rate for intracranial GCT is excellent, but there are concerns about the effects of radiotherapy on neuropsychological function and quality of life of patients., Methods: Intracranial germ cell tumors (GCT) are more common in Asia than in the West, accounting for about 15% of brain tumors in Asian children. The survival rate for intracranial GCT is excellent, but there are concerns about the effects of radiotherapy on neuropsychological function and quality of life of patients. Intracranial GCT survivors in Hong Kong aged ≥ 6 years who received cranial irradiation in the past 15 years were recruited. Neurocognitive function and performance status were assessed by the Hong Kong Wechsler Intelligence scale and Karnofsky/Lansky performance scales (KPS), respectively. Quality of life was assessed using the Pediatric Quality of Life Inventory (PedsQL) Generic Core Scales. A chart review was performed for tumor characteristics and complications related to the tumor and its treatment., Results: Twenty-five intracranial GCT survivors were recruited. Longer length of time since treatment was associated with lower IQ scores. Larger tumor size was associated with lower KPS scores. Hemiparesis, poor manual dexterity, and complications with multi-organ involvement were associated with significantly lower KPS scores. Higher irradiation dosage was associated with lower PedsQL physical scores., Conclusions: The majority of GCT survivors had average intellectual functioning, satisfactory performance status and relatively good quality of life, except in the physical aspect. Comprehensive evaluation and long-term follow-up of GCT survivors are essential to provide timely support and improve long-term outcomes.

Objective: Early onset drug-resistant epilepsy is a neurologic disorder in which 2 antiepileptic drugs fail to maintain the seizure-free status of the patient. Heterogeneous clinical presentations make the diagnosis challenging. We aim to identify the underlying genetic causes of a pediatric cohort with drug-resistant epilepsy and evaluate whether the findings can provide information on patient management., Methods: We include patients with drug-resistant epilepsy onset before 18 years of age. Singleton clinical chromosomal microarray (CMA) followed by whole exome sequencing (WES) was performed using genomic DNA. In the first-tier analysis of the exome data, we aimed to identify disease-causing mutations in 546 genes known to cause, or to be associated with, epilepsy. For negative cases, we proceeded to exome-wide analysis. Rare coding variants were interrogated for pathogenicity based on the American College of Medical Genetics and Genomics (ACMG) guidelines., Results: We recruited 50 patients. We identified 6 pathogenic or likely pathogenic mutations, giving a diagnostic yield of 12%. Mutations were found in 6 different genes: SCN8A , SCN1A , MECP2 , CDKL5 , DEPDC5 , and CHD2 . The CDKL5 variant was found to be mosaic. One variant of unknown significance (VUS) in KCNT1 was found in a patient with compatible clinical features. Of note, a reported pathogenic SCN5A mutation known to contribute to Brugada syndrome, was also found in the patient with an SCN1A mutation., Significance: Our study suggests that singleton WES is an effective diagnostic tool for drug-resistant epilepsy. Genetic diagnosis can help to consolidate the clinical diagnosis, to facilitate phenotypic expansion, and to influence treatment and management options for seizure control in our patients. In our study, a significant portion of the genetic findings are known to be associated with an increased risk of sudden unexpected death in epilepsy (SUDEP). These findings could assist with more appropriate management in patients with epilepsy.

Currently, offering whole-exome sequencing (WES) via collaboration with an external laboratory is increasingly common. However, the receipt of a WES report can be merely the beginning of a continuing exploration process rather than the end of the diagnostic odyssey. The laboratory often does not have the information the physician has, and any discrepancies in variant interpretation must be addressed by a medical geneticist. In this study, we performed diagnostic WES of 104 patients with paediatric-onset genetic diseases. The post-exome review of WES reports by the clinical geneticist led to a more comprehensive assessment of variant pathogenicity in 16 cases. The overall diagnostic yield was 41% ( n  = 43). Among these 43 diagnoses, 51% (22/43) of the pathogenic variants were nucleotide changes that have not been previously reported. The time required for the post-exome review of the WES reports varied, and 26% ( n  = 27) of the reports required an extensive amount of time (>3 h) for the geneticist to review. In this predominantly Chinese cohort, we highlight the importance of discrepancies between global and ethnic-specific frequencies of a genetic variant that complicate variant interpretation and the significance of post-exome diagnostic modalities in genetic diagnosis using WES. The challenges faced by geneticists in interpreting WES reports are also discussed., Competing Interests: The authors declare no competing interests.

Mitochondrial respiratory chain complex I consists of 44 different subunits and contains 3 functional modules: the Q-, the N- and the P-module. NDUFA9 is a Q-module subunit required for complex I assembly or stability. However, its role in complex I biogenesis has not been studied in patient fibroblasts. So far, a single patient carrying an NDUFA9 variant with a severe neonatally fatal phenotype has been reported. Via exome sequencing, we identified a novel homozygous NDUFA9 missense variant in another patient with a milder phenotype including childhood-onset progressive generalized dystonia and axonal peripheral neuropathy. We performed complex I assembly analysis using primary skin fibroblasts of both patients. Reduced complex I abundance and an accumulation of Q-module subassemblies were present in both patients but more pronounced in the severe clinical phenotype patient. The latter displayed additional accumulation of P-module subassemblies, which was not present in the milder-phenotype patient. Lentiviral complementation of both patient fibroblast cell lines with wild-type NDUFA9 rescued complex I deficiency and the assembly defects. Our report further characterizes the phenotypic spectrum of NDUFA9 deficiency and demonstrates that the severity of the clinical phenotype correlates with the severity of the effects of the different NDUFA9 variants on complex I assembly., (© 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Glucose transporter type 1 (GLUT1) deficiency syndrome (GLUT1-DS) leads to a wide range of neurological symptoms. Ketogenic diets are very efficient to control epilepsy and movement disorders. We tested a novel simple and rapid blood test in 30 patients with GLUT1-DS with predominant movement disorders, 18 patients with movement disorders attributed to other genetic defects, and 346 healthy controls. We detected significantly reduced GLUT1 expression only on red blood cells from patients with GLUT1-DS (23 patients; 78%), including patients with inconclusive genetic analysis. This test opens perspectives for the screening of GLUT1-DS in children and adults with cognitive impairment, movement disorder, or epilepsy. Ann Neurol 2017;82:133-138., (© 2017 The Authors. Annals of Neurology published by Wiley Periodicals, Inc. on behalf of American Neurological Association.)

Background: Array comparative genomic hybridization (aCGH) is recommended as a first-tier genetic test for children with autism spectrum disorder (ASD). However, interpretation of results can often be challenging partly due to the fact that copy number variants (CNVs) in non-European ASD patients are not well studied. To address this literature gap, we report the CNV findings in a cohort of Chinese children with ASD., Methods: DNA samples were obtained from 258 Chinese ASD patients recruited from a child assessment center between January 2011 and August 2014. aCGH was performed using NimbleGen-CGX-135k or Agilent-CGX 60k oligonucleotide array. Results were classified based on existing guidelines and literature., Results: Ten pathogenic CNVs and one likely pathogenic CNV were found in nine patients, with an overall diagnostic yield of 3.5%. A 138 kb duplication involving 3' exons of DPP10 (arr[GRCh37] 2q14.1(116534689&#95;116672358)x3), reported to be associated with ASD, was identified in one patient (0.39%). The same CNV was reported as variant of uncertain significance (VUS) in DECIPHER database. Multiple individuals of typical development carrying a similar duplication were identified among our ancestry-matched control with a frequency of 6/653 (0.92%) as well as from literature and genomic databases., Conclusions: The DPP10 duplication is likely a benign CNV polymorphism enriched in Southern Chinese with a population frequency of ~1%. This highlights the importance of using ancestry-matched controls in interpretation of aCGH findings.