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Genes May 2024X-linked hypophosphatemia (XLH) is a rare inherited disorder of renal phosphate wasting with a highly variable phenotype caused by loss-of-function variants in the...
X-linked hypophosphatemia (XLH) is a rare inherited disorder of renal phosphate wasting with a highly variable phenotype caused by loss-of-function variants in the gene. The diagnosis of individuals with mild phenotypes can be challenging and often delayed. Here, we describe a three-generation family with a very mild clinical presentation of XLH. The diagnosis was unexpectedly found in a 39-year-old woman who was referred for genetic testing due to an unclear childhood diagnosis of a tubulopathy. Genetic testing performed by next-generation sequencing using a kidney disease gene panel identified a novel non-canonical splice site variant in the gene. Segregation analysis detected that the consultand's father, who presented with hypophosphatemia and decreased tubular phosphate reabsorption, and the consultand's son also carried this variant. RNA studies demonstrated that the non-canonical splice site variant partially altered the splicing of the gene, as both wild-type and aberrant splicing transcripts were detected in the two male members with only one copy of the gene. In conclusion, this case contributes to the understanding of the relationship between splicing variants and the variable expressivity of XLH disease. The mild phenotype of this family can be explained by the coexistence of transcripts with aberrant and wild-type splicing.
Topics: Humans; PHEX Phosphate Regulating Neutral Endopeptidase; Adult; Female; Familial Hypophosphatemic Rickets; Male; Pedigree; RNA Splice Sites; RNA Splicing; Phenotype; Genetic Diseases, X-Linked; Mutation
PubMed: 38927615
DOI: 10.3390/genes15060679 -
Biomedicines Jun 2024Perfluorinated alkyl acids (PFAAs) are persistent organic pollutants affected by BMI and ethnicity, with contradictory reports of association with vitamin D deficiency.
BACKGROUND
Perfluorinated alkyl acids (PFAAs) are persistent organic pollutants affected by BMI and ethnicity, with contradictory reports of association with vitamin D deficiency.
METHODS
Twenty-nine Caucasian women with non-obese polycystic ovary syndrome (PCOS) and age- and BMI-matched Caucasian control women ( = 30) were recruited. Paired serum samples were analyzed for PFAAs ( = 13) using high-performance liquid chromatography-tandem mass spectrometry. Tandem mass spectrometry determined levels of 25(OH)D and the active 1,25(OH)D.
RESULTS
Women with and without PCOS did not differ in age, weight, insulin resistance, or systemic inflammation (C-reactive protein did not differ), but the free androgen index was increased. Four PFAAs were detected in all serum samples: perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), and perfluorohexane sulfonic acid (PFHxS). Serum PFOS was higher in PCOS versus controls (geometric mean [GM] 3.9 vs. 3.1 ng/mL, < 0.05). Linear regression modeling showed that elevated PFHxS had higher odds of a lower 25(OH)D (OR: 2.919, 95% CI 0.82-5.75, = 0.04). Vitamin D did not differ between cohorts and did not correlate with any PFAAs, either alone or when the groups were combined. When vitamin D was stratified into sufficiency (>20 ng/mL) and deficiency (<20 ng/mL), no correlation with any PFAAs was seen.
CONCLUSIONS
While the analyses and findings here are exploratory in light of relatively small recruitment numbers, when age, BMI, and insulin resistance are accounted for, the PFAAs do not appear to be related to 25(OH)D or the active 1,25(OH)D in this Caucasian population, nor do they appear to be associated with vitamin D deficiency, suggesting that future studies must account for these factors in the analysis.
PubMed: 38927462
DOI: 10.3390/biomedicines12061255 -
Scientific Reports Jun 2024Low concentrations of circulating 25-hydroxy-vitamin D are observationally associated with an increased risk of subclinical atherosclerosis and cardiovascular disease....
Low concentrations of circulating 25-hydroxy-vitamin D are observationally associated with an increased risk of subclinical atherosclerosis and cardiovascular disease. However, randomized controlled trials have not reported the beneficial effects of vitamin D supplementation on atherosclerotic cardiovascular disease (ASCVD) outcomes. Whether genetically predicted vitamin D status confers protection against the development of carotid artery plaque, a powerful predictor of subclinical atherosclerosis, remains unknown. We conducted a two-sample Mendelian randomization (MR) study to explore the association of genetically predicted vitamin D status and deficiency with the risk of developing carotid artery plaque. We leveraged three genome-wide association studies (GWAS) of vitamin D status and one GWAS of vitamin D deficiency. We used the inverse-variance weighted (IVW) approach as our main method, and MR-Egger, weighted-median, and radialMR as MR sensitivity analyses. We also conducted sensitivity analyses using biologically plausible genetic instruments located within genes encoding for vitamin D metabolism (GC, CYP2R1, DHCR7, CYP24A1). We did not find significant associations between genetically predicted vitamin D status (Odds ratio (OR) = 0.99, P = 0.91) and deficiency (OR = 1.00, P = 0.97) with the risk of carotid artery plaque. We additionally explored the potential causal effect of vitamin D status on coronary artery calcification (CAC) and carotid intima-media thickness (cIMT), two additional markers of subclinical atherosclerosis, and we did not find any significant association (β = - 0.14, P = 0.23; β = 0.005, P = 0.19). These findings did not support the causal effects of vitamin D status and deficiency on the risk of developing subclinical atherosclerosis.
Topics: Humans; Mendelian Randomization Analysis; Vitamin D; Vitamin D Deficiency; Plaque, Atherosclerotic; Genome-Wide Association Study; Carotid Artery Diseases; Polymorphism, Single Nucleotide; Risk Factors; Genetic Predisposition to Disease; Female; Male; Carotid Arteries
PubMed: 38926411
DOI: 10.1038/s41598-024-64731-z -
BMJ Case Reports Jun 2024A major complication with extracorporeal membrane oxygenation (ECMO) is bleeding which can occur in up to 40% of cases and can be life-threatening. Minor bleeding may be...
A major complication with extracorporeal membrane oxygenation (ECMO) is bleeding which can occur in up to 40% of cases and can be life-threatening. Minor bleeding may be overlooked and under-reported. While some of the underlying mechanisms such as platelet injury and anticoagulation therapy have been identified, several other factors are still under-researched. Here, we describe a unique case of a subtle mucosal membrane bleeding that is found to be associated with vitamin C deficiency while on treatment with ECMO. Investigating vitamin C levels may be useful in understanding causes of bleeding in some patients on ECMO therapy, particularly if there are risk factors for malnutrition.
Topics: Humans; Extracorporeal Membrane Oxygenation; Ascorbic Acid Deficiency; Male; Hemorrhage; Ascorbic Acid; Female; Middle Aged; Mucous Membrane
PubMed: 38926124
DOI: 10.1136/bcr-2023-259185 -
The American Journal of the Medical... Jun 2024The etiology of Hashimoto's thyroiditis (HT) involves genetic and environmental factors. There is a lack of clarity regarding the relationship between Vitamin D and HT....
BACKGROUND
The etiology of Hashimoto's thyroiditis (HT) involves genetic and environmental factors. There is a lack of clarity regarding the relationship between Vitamin D and HT. This study aimed to investigate the effect of Vitamin D and gene polymorphisms on thyroid peroxidase antibody (TPOAb) positivity.
METHODS
A total of 9,966 participants were included from a survey conducted in East China from 2014 to 2016. We measured the levels of 25(OH)D, thyroid hormones and autoimmune antibodies. rs11675434, rs9277555, and rs301799 were genotyped. Based on these 3 SNPs, a weighted genetic risk score was calculated for TPOAb.
RESULTS
The proportion of females in the TPOAb-positive group was greater than that in the TPOAb-negative group (74.2% vs. 57.2%, P<0.001). Vitamin D levels were lower in the TPOAb-positive group than in the TPOAb-negative group (40.07±11.87 vs. 40.80±12.84, P=0.01). The GG genotype of rs9277555 and the TT genotype of rs11675434 were correlated with the risk of TPOAb positivity (OR=1.34, 95% CI 1.13-1.59, P=0.001; OR=1.29, 95% CI 1.06-1.58, P=0.01). TPOAb-GRS was associated with TPOAb positivity (OR=3.17, 95% CI 1.72-5.84; P<0.001). When stratified by Vitamin D group, the association between TPOAb-GRS and TPOAb positivity existed only in the Vitamin D deficiency group (OR=3.41, 95% CI 1.73-6.70 P<0.001) but not in the control group (OR=2.45, 95% CI 0.59-10.19, P=0.22).
CONCLUSIONS
This study suggested that TPOAb-GRS was associated with TPOAb positivity in the Han Chinese population, mainly due to rs9277555 and rs11675434. The hereditary effect of TPOAb positivity differed depending on Vitamin D status.
PubMed: 38925429
DOI: 10.1016/j.amjms.2024.06.014 -
The New England Journal of Medicine Jun 2024
Topics: Humans; Male; Young Adult; Diagnosis, Differential; Fatigue; Sweating; Pancytopenia; Vitamin B 12 Deficiency
PubMed: 38924749
DOI: 10.1056/NEJMc2404287 -
The New England Journal of Medicine Jun 2024
Topics: Humans; Male; Young Adult; Diagnosis, Differential; Fatigue; Sweating; Pancytopenia; Vitamin B 12 Deficiency
PubMed: 38924748
DOI: 10.1056/NEJMc2404287 -
The New England Journal of Medicine Jun 2024
Topics: Humans; Male; Young Adult; Diagnosis, Differential; Fatigue; Pancytopenia; Sweating; Vitamin B 12 Deficiency
PubMed: 38924747
DOI: 10.1056/NEJMc2404287 -
Science Translational Medicine Jun 2024Vitamin B12 is critical for hematopoiesis and myelination. Deficiency can cause neurologic deficits including loss of coordination and cognitive decline. However,...
Vitamin B12 is critical for hematopoiesis and myelination. Deficiency can cause neurologic deficits including loss of coordination and cognitive decline. However, diagnosis relies on measurement of vitamin B12 in the blood, which may not accurately reflect the concentration in the brain. Using programmable phage display, we identified an autoantibody targeting the transcobalamin receptor (CD320) in a patient with progressive tremor, ataxia, and scanning speech. Anti-CD320 impaired cellular uptake of cobalamin (B12) in vitro by depleting its target from the cell surface. Despite a normal serum concentration, B12 was nearly undetectable in her cerebrospinal fluid (CSF). Immunosuppressive treatment and high-dose systemic B12 supplementation were associated with increased B12 in the CSF and clinical improvement. Optofluidic screening enabled isolation of a patient-derived monoclonal antibody that impaired B12 transport across an in vitro model of the blood-brain barrier (BBB). Autoantibodies targeting the same epitope of CD320 were identified in seven other patients with neurologic deficits of unknown etiology, 6% of healthy controls, and 21.4% of a cohort of patients with neuropsychiatric lupus. In 132 paired serum and CSF samples, detection of anti-CD320 in the blood predicted B12 deficiency in the brain. However, these individuals did not display any hematologic signs of B12 deficiency despite systemic CD320 impairment. Using a genome-wide CRISPR screen, we found that the low-density lipoprotein receptor serves as an alternative B12 uptake pathway in hematopoietic cells. These findings dissect the tissue specificity of B12 transport and elucidate an autoimmune neurologic condition that may be amenable to immunomodulatory treatment and nutritional supplementation.
Topics: Humans; Vitamin B 12 Deficiency; Vitamin B 12; Autoantibodies; Female; Receptors, Cell Surface; Antigens, CD; Middle Aged; Autoimmune Diseases; Blood-Brain Barrier; Male
PubMed: 38924428
DOI: 10.1126/scitranslmed.adl3758 -
Journal of Cachexia, Sarcopenia and... Jun 2024Frailty is a common geriatric syndrome associated with reduced reserves and increased vulnerability to stressors among older adults. Vitamin D deficiency has been...
BACKGROUND
Frailty is a common geriatric syndrome associated with reduced reserves and increased vulnerability to stressors among older adults. Vitamin D deficiency has been implicated in frailty, as it is essential for maintaining musculoskeletal functions. The relationship between dynamic changes in vitamin D levels and frailty over time has not been extensively studied.
METHODS
This study utilized data from the UK Biobank. Baseline and longitudinal changes in vitamin D levels were measured. Frailty status was assessed using both the frailty phenotype and frailty index approaches and classified as robust, pre-frail, or frail. Changes in frailty status were assessed by frailty phenotype at baseline (2006-2010) and the follow-up (2012-2013). Mixed effect model was performed to examine the association between vitamin D levels and frailty status. Using multistate transition models, we assessed the impact of increasing vitamin D levels on the probabilities of transitioning between robust, pre-frail, and frail states.
RESULTS
Based on the frailty phenotype, 287 926 individuals (64.8%) were identified as having various degrees of frailty (median age 58.00 [51.00, 64.00] years, 55.9% females). Using the frailty index approach, 250 566 individuals (56%) were found to have different levels of frailty (median age 59.00 [51.00, 64.00] years, 55.3% females). Baseline vitamin D levels were found to be significantly associated with frailty status (frailty phenotype: OR 0.78, 95% CI [0.76, 0.79], P < 0.001; frailty index: OR 0.80, 95% CI [0.78, 0.81], P < 0.001). Dynamic changes in vitamin D levels were also found to be associated with changes in frailty over time. Furthermore, increasing vitamin D levels were associated with a transition from frailty to a healthier status. A higher degree of vitamin D (estimated at 1 nmol/L) was associated with a lower risk of transitioning from robust to prefrail (HR 0.997, 95% CI [0.995, 0.999]) and from prefrail to frail (HR 0.992, 95% CI [0.988, 0.995]).
CONCLUSIONS
This study highlights the importance of vitamin D in the context of frailty. Low vitamin D levels are associated with increased frailty risk, while increasing vitamin D levels may contribute to improving frailty status. Recognizing the relationship between vitamin D levels and frailty can inform personalized management and early interventions for frail individuals. Further research is needed to explore the potential effects of vitamin D interventions on frailty and deepen our understanding of the biological connections between vitamin D and frailty.
PubMed: 38923848
DOI: 10.1002/jcsm.13525