Publications by authors named "Charles A Leduc"

Aims: This study examined the association of gravida C-peptide with progeny islet function and insulin sensitivity in the Hyperglycemia and Adverse Pregnancy Outcome Follow-up Study (HAPO FUS).

Methods: Pregnancy 3rd trimester oral glucose tolerance test (OGTT), cord blood, and offspring OGTT glucose, C-peptide and insulin at age 10-14 years were analyzed for 4,121 mother-child dyads. Gravida fasting and 1-hour C-peptide concentration correlations with cord blood and childhood C-peptide, insulin, insulinogenic index and insulin sensitivity, and insulin resistance [HOMA-IR]), were assessed by multiple linear regression.

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Article Synopsis
  • - The study aimed to compare maternal and offspring health outcomes after different types of prepregnancy weight loss surgeries (bariatric surgery) against a control group that did not have surgery.
  • - Conducted from January 2020 to March 2023, the research involved analyzing the growth trajectories of children born to mothers who had Roux-en-Y gastric bypass or sleeve gastrectomy versus those without surgery, focusing on weight, length, and BMI.
  • - Results showed similar gestational weight gain between groups, but increased pregnancy complications for MBS participants; offspring from MBS surgeries had lower birth weights but higher weight gains at 24 months, with notable differences in outcomes based on the type of surgery and child sex. *
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Purpose Of Review: The goal of this paper is to aggregate information on monogenic contributions to obesity in the past five years and to provide guidance for genetic testing in clinical care.

Recent Findings: Advances in sequencing technologies, increasing awareness, access to testing, and new treatments have increased the utilization of genetics in clinical care. There is increasing recognition of the prevalence of rare genetic obesity from variants with mean allele frequency < 5% -new variants in known genes as well as identification of novel genes- causing monogenic obesity.

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Accurate identification of germline variants (DNVs) remains a challenging problem despite rapid advances in sequencing technologies as well as methods for the analysis of the data they generate, with putative solutions often involving filters and visual inspection of identified variants. Here, we present a purely informatic method for the identification of DNVs by analyzing short-read genome sequencing data from proband-parent trios. Our method evaluates variant calls generated by three genome sequence analysis pipelines utilizing different algorithms-GATK HaplotypeCaller, DeepTrio and Velsera GRAF-exploring the assumption that a requirement of consensus can serve as an effective filter for high-quality DNVs.

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Purpose: YKT6 plays important roles in multiple intracellular vesicle trafficking events but has not been associated with Mendelian diseases.

Methods: We report 3 unrelated individuals with rare homozygous missense variants in YKT6 who exhibited neurological disease with or without a progressive infantile liver disease. We modeled the variants in Drosophila.

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Aging is underpinned by pronounced metabolic decline; however, the drivers remain obscure. Here, we report that IgG accumulates during aging, particularly in white adipose tissue (WAT), to impair adipose tissue function and metabolic health. Caloric restriction (CR) decreases IgG accumulation in WAT, whereas replenishing IgG counteracts CR's metabolic benefits.

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This review analyzes the published evidence regarding maternal factors that influence the developmental programming of long-term adiposity in humans and animals via the central nervous system (CNS). We describe the physiological outcomes of perinatal underfeeding and overfeeding and explore potential mechanisms that may mediate the impact of such exposures on the development of feeding circuits within the CNS-including the influences of metabolic hormones and epigenetic changes. The perinatal environment, reflective of maternal nutritional status, contributes to the programming of offspring adiposity.

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Bassoon (BSN) is a component of a hetero-dimeric presynaptic cytomatrix protein that orchestrates neurotransmitter release with Piccolo (PCLO) from glutamatergic neurons throughout the brain. Heterozygous missense variants in BSN have previously been associated with neurodegenerative disorders in humans. We performed an exome-wide association analysis of ultra-rare variants in about 140,000 unrelated individuals from the UK Biobank to search for new genes associated with obesity.

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Hearing loss and peripheral neuropathy are two clinical entities that are genetically and phenotypically heterogeneous and sometimes co-occurring. Using exome sequencing and targeted segregation analysis, we investigated the genetic etiology of peripheral neuropathy and hearing loss in a large Ashkenazi Jewish family. Moreover, we assessed the production of the candidate protein via western blotting of lysates from fibroblasts from an affected individual and an unaffected control.

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Bassoon ( ) is a component of a hetero-dimeric presynaptic cytomatrix protein that orchestrates neurotransmitter release with Piccolo ( ) from glutamatergic neurons throughout the brain. Heterozygous missense variants in have previously been associated with neurodegenerative disorders in humans. We performed an exome-wide association analysis of ultra-rare variants in about 140,000 unrelated individuals from the UK Biobank to search for new genes associated with obesity.

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Understanding the developmental origins of health and disease is integral to overcome the global tide of obesity and its metabolic consequences, including atherosclerotic cardiovascular disease, type 2 diabetes, hyperlipidemia, and nonalcoholic fatty liver disease. The rising prevalence of obesity has been attributed, in part, to environmental factors including the globalization of the western diet and unhealthy lifestyle choices. In this review we argue that and such exposures come into play from conception significantly impact overall risk of obesity and later health outcomes.

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Mutations in HNF1A cause Maturity Onset Diabetes of the Young (HNF1A-MODY). To understand mechanisms of β-cell dysfunction, we generated stem cell-derived pancreatic endocrine cells with hypomorphic mutations in HNF1A. HNF1A-deficient β-cells display impaired basal and glucose stimulated-insulin secretion, reduced intracellular calcium levels in association with a reduction in CACNA1A expression, and accumulation of abnormal insulin granules in association with SYT13 down-regulation.

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Background: Lowe syndrome (LS) is an X linked disease caused by pathogenic variants in the gene that impacts approximately 1 in 500 000 children. Classic features include congenital cataract, cognitive/behavioural impairment and renal tubulopathy.

Methods: This study is a retrospective review of clinical features reported by family based survey conducted by Lowe Syndrome Association.

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is a pleiotropic gene and the actions of leptin extend well beyond simply acting as the signal of the size of adipose tissue stores originally proposed. This is a discussion of the multi-system interactions of leptin with the development of the neural systems regulating energy stores, and the subsequent maintenance of energy stores throughout the lifespan. The prenatal, perinatal, and later postnatal effects of leptin on systems regulating body energy stores and on the energy stores themselves are heavily influenced by the nutritional environment which leptin exposure occurs.

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Exome and genome sequencing were used to identify the genetic etiology of a severe neurodevelopmental disorder in two unrelated Ashkenazi Jewish families with three affected individuals. The clinical findings included a prenatal presentation of microcephaly, polyhydramnios and clenched hands while postnatal findings included microcephaly, severe developmental delay, dysmorphism, neurologic deficits, and death in infancy. A shared rare homozygous, missense variant (c.

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Background/objectives: The murine postnatal leptin surge occurs within the first 4 weeks of life and is critical for neuronal projection development within hypothalamic feeding circuits. Here we describe the influence of nutritional status on the timing and magnitude of the postnatal leptin surge in mice.

Methods: Plasma leptin concentrations were measured 1-3 times per week for the first 4 weeks of life in C57BL/6J pups reared in litters adjusted to 3 (small), 7-8 (normal), or 11-12 (large) pups per dam fed breeder chow or raised in litters of 7-8 by dams fed high-fat diet (HFD) ad libitum starting either prior to conception or at parturition.

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Energy balance is controlled by interconnected brain regions in the hypothalamus, brainstem, cortex, and limbic system. Gene expression signatures of these regions can help elucidate the pathophysiology underlying obesity. RNA sequencing was conducted on P56 C57BL/6NTac male mice and E14.

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Article Synopsis
  • The metabolic syndrome is linked to problems in both micro- and macrovascular systems, resulting in high blood pressure, but the mechanisms behind this are not fully understood.
  • Research reveals that increased levels of leptin due to obesity can selectively expand the microvascular structure in brain regions that help regulate blood pressure.
  • The study highlights that the HIF1α-VEGF signaling pathway in hypothalamic astrocytes is crucial for this process, indicating that disrupting this pathway can prevent obesity-related hypertension and sympathetic nervous system overactivity.
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Objectives: There have been few large-scale studies utilizing exome sequencing for genetically undiagnosed maturity onset diabetes of the young (MODY), a monogenic form of diabetes that is under-recognized. We describe a cohort of 160 individuals with suspected monogenic diabetes who were genetically assessed for mutations in genes known to cause MODY.

Methods: We used a tiered testing approach focusing initially on and and then expanding to exome sequencing for those individuals without identified mutations in or .

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Bardet-Biedl syndrome (BBS) is a rare autosomal recessive disorder caused by mutations in genes encoding components of the primary cilium and is characterized by hyperphagic obesity. To investigate the molecular basis of obesity in human BBS, we developed a cellular model of BBS using induced pluripotent stem cell-derived (iPSC-derived) hypothalamic arcuate-like neurons. BBS mutations BBS1M390R and BBS10C91fsX95 did not affect neuronal differentiation efficiency but caused morphological defects, including impaired neurite outgrowth and longer primary cilia.

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Naltrexone/bupropion (NB) is a US Food and Drug Administration-approved antiobesity medication. Clinical trials have shown variable weight loss, with responders and non-responders. NB is believed to act on central dopaminergic pathways to suppress appetite.

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Article Synopsis
  • - Leptin is a hormone that helps regulate food intake by signaling the brain about fat stores, and its deficiency can lead to severe obesity, especially in cases of rare genetic mutations.
  • - A study analyzed genetic data from over 57,000 individuals to find genetic variants that affect leptin levels, discovering five new variants linked to leptin concentration.
  • - One significant variant, Val94Met, was found specifically in individuals of African ancestry, associated with lower leptin levels and higher BMI in young children, indicating leptin's role in managing early body fat.
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Leptin plays a role in central nervous system developmental programs and intercurrent physiological processes related to body fat regulation. The timing and neuromolecular mechanisms for these effects are relevant to the prevention and treatment of obesity. Factors implicated in a body weight "set point" including dietary fat, circulating leptin, and other adipokines tend to covary with adiposity and are difficult to disarticulate experimentally.

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The clinical use of the hormone leptin, a key regulator of food intake, to treat the most common instances of obesity has so far failed. In this issue, Zhao et al. (2019) report that, paradoxically, reducing leptin levels in obese mice increases their sensitivity to the concentrations that remain, and leads to reductions in weight gain, thus suggesting why these earlier trials may have failed and possibly a new approach to treating obesity.

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Two siblings, one male and one female, ages 6 and 13 yr old, have similar clinical features of global developmental delay, multiple congenital anomalies affecting the cardiac, genitourinary, and skeletal systems, and abnormal eye movements. Whole-genome sequencing revealed a homozygous splice variant (NM_014462.3:c.

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