Publications by authors named "Stacey K H Tay"

Article Synopsis
  • Mitochondrial dysfunction and low NAD levels are linked to aging and muscle loss (sarcopenia), but it's unclear if these issues come from local or systemic factors.
  • Research shows that trigonelline, a natural compound similar to nicotinic acid, positively affects NAD levels and muscle health across different species, including humans.
  • Trigonelline enhances mitochondrial function, reduces muscle wasting, and increases strength and lifespan, suggesting that dietary trigonelline could be a helpful strategy against age-related muscle decline.
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This paper provides an overview of the different types of mitochondrial myopathies (MM), associated phenotypes, genotypes as well as a practical clinical approach towards disease diagnosis, surveillance, and management. nDNA-related MM are more common in pediatric-onset disease whilst mtDNA-related MMs are more frequent in adults. Genotype-phenotype correlation in MM is challenging due to clinical and genetic heterogeneity.

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Background: Neurological complications with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) omicron variant have been reported in adults; however, there are little data in the pediatric population. We aimed to report on the prevalence and clinical characteristics of children with neurological symptoms during the SARS-CoV-2 omicron wave.

Methods: This was a single-center, retrospective cohort review of children (<18 years old) hospitalized for SARS-CoV-2 infection from December 2, 2021, to June 30, 2022.

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Background: Mitochondrial dysfunction has been implicated in sarcopenia. P magnetic resonance spectroscopy (MRS) enables non-invasive measurement of adenosine triphosphate (ATP) synthesis rates to probe mitochondrial function. Here, we assessed muscle energetics in older sarcopenic and non-sarcopenic men and compared with muscle biopsy-derived markers of mitochondrial function.

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Aim: We describe a cohort of five patients with limb-girdle muscular dystrophy (LGMD) 2G/LGMD-R7 in a South-east Asian cohort.

Background: LGMD2G/LGMD-R7-telethonin-related is caused by mutations in the TCAP gene that encodes for telethonin.

Methods: We identified consecutive patients with LGMD2G/LGMD-R7-telethonin-related, diagnosed at the National Neuroscience Institute (NNI) and National University Hospital (NUH) between January 2000 and June 2021.

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Moderate to hyper-expansion of trinucleotide repeats at the FRAXA and FRAXE fragile sites, with or without concurrent hypermethylation, has been associated with intellectual disability and other conditions. Unlike molecular diagnosis of FMR1 CGG repeat expansions in FRAXA, current detection of AFF2 CCG repeat expansions in FRAXE relies on low-throughput and otherwise inefficient techniques combining Southern blot analysis and PCR. A novel triplet-primed PCR assay was developed for simultaneous screening for trinucleotide repeat expansions at the FRAXA and FRAXE fragile sites, and was validated using archived clinical samples of known FMR1 and AFF2 genotypes.

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Despite improving services and care for individuals with autism spectrum disorder, functional outcomes such as daily living skills tend to be suboptimal for many. This study wanted to identify modifiable early intervention factors that are associated with better outcomes and possible high-risk groups of children who are at risk of poorer outcomes. Participants included 193 children aged between 5 and 12 years of age whose parents provided information on their family background and early intervention characteristics.

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Article Synopsis
  • Sarcopenia, a condition causing muscle wasting and weakness in older adults, is less understood compared to general muscle aging, affecting physical independence and survival.
  • A study analyzed muscle biopsies from 119 older men across Singapore, the UK, and Jamaica, finding that individuals with sarcopenia exhibit clear signs of mitochondrial dysfunction in their muscles.
  • Key indicators of this dysfunction include reduced signaling related to energy production, fewer mitochondria, diminished respiratory complex activity, and low levels of NAD, highlighting the critical role of mitochondrial metabolism in age-related muscle loss.
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The VARS2 gene encodes a mitochondrial valyl-transfer RNA synthetase which is used in mitochondrial translation. To date, several patients with VARS2 pathogenic variants have been described in the literature. These patients have features of lactic acidosis with encephalomyopathy.

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The diagnosis of childhood neurological disorders remains challenging given the overlapping clinical presentation across subgroups and heterogeneous presentation within subgroups. To determine the underlying genetic cause of a severe neurological disorder in a large consanguineous Pakistani family presenting with severe scoliosis, anarthria and progressive neuromuscular degeneration, we performed genome-wide homozygosity mapping accompanied by whole-exome sequencing in two affected first cousins and their unaffected parents to find the causative mutation. We identified a novel homozygous splice-site mutation (c.

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MED13L is a component subunit of the Mediator complex, an important regulator of transcription that is highly conserved across eukaryotes. Here, we report MED13L disruption in a translocation t(12;19) breakpoint of a patient with Pierre-Robin syndrome, moderate intellectual disability, craniofacial anomalies, and muscular defects. The phenotype is similar to previously described patients with MED13L haploinsufficiency.

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Delineating candidate genes at the chromosomal breakpoint regions in the apparently balanced chromosome rearrangements (ABCR) has been shown to be more effective with the emergence of next-generation sequencing (NGS) technologies. We employed a large-insert (7-11 kb) paired-end tag sequencing technology (DNA-PET) to systematically analyze genome of four patients harbouring cytogenetically defined ABCR with neurodevelopmental symptoms, including developmental delay (DD) and speech disorders. We characterized structural variants (SVs) specific to each individual, including those matching the chromosomal breakpoints.

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Spinal muscular atrophy (SMA) is a common neuromuscular disorder with autosomal recessive inheritance, resulting in the degeneration of motor neurons. The incidence of the disease has been estimated at 1 in 6000-10,000 newborns with a carrier frequency of 1 in 40-60. SMA is caused by mutations of the SMN1 gene, located on chromosome 5q13.

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Glycogen storage disease type IV (GSD IV) is a rare autosomal recessive disorder caused by deficiency of the glycogen branching enzyme (GBE). The diagnostic feature of the disease is the accumulation of a poorly branched form of glycogen known as polyglucosan (PG). The disease is clinically heterogeneous, with variable tissue involvement and age of disease onset.

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Mutations in the Conserved Oligomeric Golgi (COG) complex give rise to type II congenital disorders of glycosylation (CDG). Thus far, mutations have been identified in 6 of the 8 COG subunits. Here we present data identifying a previously reported CDG-IIx case from Singapore as a new COG4 patient with 2 novel mutations leading to p.

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Heteroduplex formation, required for the complete detection of hemi/homozygotes using high-resolution melting analysis, can be induced either by pre-PCR mixing of genomic DNAs or by post-PCR mixing of PCR products from unknown and reference samples. This study investigates the effects of both methods using two single nucleotide polymorphisms in X-linked DMD gene. The results show that both methods resulted in the same effect when mixing samples with the same gene copy number.

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Background: The interleukin-2-mediated immune response is critical for host defense against infectious pathogens. Cytokine-inducible SRC homology 2 (SH2) domain protein (CISH), a suppressor of cytokine signaling, controls interleukin-2 signaling.

Methods: Using a case-control design, we tested for an association between CISH polymorphisms and susceptibility to major infectious diseases (bacteremia, tuberculosis, and severe malaria) in blood samples from 8402 persons in Gambia, Hong Kong, Kenya, Malawi, and Vietnam.

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Introduction: While paediatric strokes are fairly uncommon, they are often associated with significant long-term disability. Diagnosis is often delayed because of the need to exclude conditions that mimic stroke. Understanding the outcomes related to stroke in children is important in the development of secondary prevention strategies.

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The use of lipid-lowering statins has been associated with raised serum muscle enzymes and, occasionally, with rhabdomyolysis, especially in patients with pre-existing metabolic myopathies. The A3243G mutation is one of the most common mutations associated with mitochondrial disorders. A teenager harboring the A3243G mutation had the unusual association of hereditary glomerulopathy and recurrent episodes of raised creatine kinase levels with the use of lipid-lowering agents.

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Here we report the cloning and characterization of a novel PDE4D isoform (PDE4D11) identified in mouse brain cDNA. This novel isoform has a unique isoform-specific 5'-UTR and N-terminal sequence, whereas, downstream regulatory N-terminal and catalytic C-terminal regions are homologous to other long PDE4D isoforms (Ex2-15). In silico analysis of PDE4D11 cDNA transcript identified the predicted translational start site and the use of a different transcriptional start site compared to other PDE4D isoforms.

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We report here the cloning and characterization of short and supershort mouse PDE4D isoforms. PDE4D is one of the phosphodiesterase enzyme families with multiple promoters and splice variants. PDE4 isoforms present in humans, rats and mice share considerable homology in their catalytic and regulatory domains.

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Posttreatment effects of phenobarbital (30 mg/kg I.P. per day for 5 days) on liver mitochondrial TEM ultra-structure in adult rats were studied.

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