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Child's Nervous System : ChNS :... Jul 2023Neural tube defects (NTDs) are common birth defects and contribute to life-long disabilities, high medical care costs, and perinatal and child mortality. This review is... (Review)
Review
Neural tube defects (NTDs) are common birth defects and contribute to life-long disabilities, high medical care costs, and perinatal and child mortality. This review is a primer on prevalence, causes, and evidence-based prevention strategies for NTDs. The estimated average global prevalence of NTDs is two cases per 1000 births, amounting to approximately 214,000-322,000 affected pregnancies worldwide annually. Prevalence and associated adverse outcomes are disproportionately high in developing countries. NTDs have multiple risk factors including genetic and non-genetic (i.e., maternal nutritional status, pre-pregnancy diabetes, early pregnancy exposure to valproic acid (anti-epileptic medication), and a previous pregnancy affected by a NTD) factors. Maternal folate insufficiency before and during early pregnancy is the most common risk factor and is preventable. Folic acid (vitamin B9) is required for formation of the neural tube early in pregnancy, around 28 days after conception, when most women are unaware of their pregnancies. Current guidelines recommend that all women planning or capable of pregnancy take a daily supplement containing 400-800 μg of folic acid. Mandatory folic acid fortification of staple foods (e.g., wheat flour, maize flour, rice) is safe, economical, and the effective intervention for primary prevention of NTDs. Currently, about 60 countries are implementing mandatory folic acid fortification of staple foods, preventing just a quarter of all preventable NTD cases worldwide. There is an urgent need for active champions, including neurosurgeons and other healthcare providers, to generate political will and promote effective mandatory food fortification with folic acid, and reach equitable primary prevention of NTDs in all countries.
Topics: Pregnancy; Child; Female; Humans; Flour; Prevalence; Food, Fortified; Triticum; Neural Tube Defects; Folic Acid; Primary Prevention
PubMed: 36882610
DOI: 10.1007/s00381-023-05910-7 -
Child's Nervous System : ChNS :... Oct 2023Among fetal surgical procedures, neurosurgery stands out due to the number of cases and the possibility of developing new procedures that can be performed in the fetal... (Review)
Review
Among fetal surgical procedures, neurosurgery stands out due to the number of cases and the possibility of developing new procedures that can be performed in the fetal period. To perform fetal neurosurgical procedures, there is a need for specialized centers that have experts in the diagnosis of fetal pathologies and a highly complex obstetrics service with specialized maternal-fetal teams associated with a pediatric neurosurgery center with expertise in the diverse pathologies of the fetus and the central nervous system that offers multidisciplinary follow-up during postnatal life. Services that do not have these characteristics should refer their patients to these centers to obtain better treatment results. It is essential that the fetal neurosurgical procedure be performed by a pediatric neurosurgeon with extensive experience, as he will be responsible for monitoring these patients in the postnatal period and for several years. The objective of this manuscript is to demonstrate the diagnostic and treatment possibilities, in the fetal period, of some neurosurgical diseases such as hydrocephalus, tumors, occipital encephalocele, and myelomeningocele.
Topics: Male; Pregnancy; Female; Humans; Child; Neurosurgery; Fetus; Neurosurgical Procedures; Hydrocephalus; Meningomyelocele
PubMed: 37606832
DOI: 10.1007/s00381-023-06109-6 -
JAMA Aug 2023Neural tube defects are among the most common birth defects in the US.
IMPORTANCE
Neural tube defects are among the most common birth defects in the US.
OBJECTIVE
To review new evidence on the benefits and harms of folic acid supplementation for the prevention of neural tube defects to inform the US Preventive Services Task Force.
EVIDENCE REVIEW
Sources included PubMed, Cochrane Library, Embase, and trial registries from July 1, 2015, through July 2, 2021; references; and experts, with surveillance through February 10, 2023. Two investigators independently reviewed English-language randomized studies and nonrandomized cohort studies in very highly developed countries that focused on the use of folic acid supplementation for the prevention of neural tube defect-affected pregnancies; methodological quality was dually and independently assessed.
FINDINGS
Twelve observational studies (reported in 13 publications) were eligible for this limited update (N = 1 244 072). Of these, 3 studies (n = 990 372) reported on the effect of folic acid supplementation on neural tube defects. For harms, 9 studies were eligible: 1 randomized clinical trial (n = 431) reported on variations in twin delivery, 7 observational studies (n = 761 125) reported on the incidence of autism spectrum disorder, and 1 observational study (n = 429 004) reported on maternal cancer. Two cohort studies and 1 case-control study newly identified in this update reported on the association between folic acid supplementation and neural tube defects (n = 990 372). One cohort study reported a statistically significant reduced risk of neural tube defects associated with folic acid supplementation taken before pregnancy (adjusted relative risk [aRR], 0.54 [95% CI, 0.31-0.91]), during pregnancy (aRR, 0.62 [95% CI, 0.39-0.97]), and before and during pregnancy (aRR, 0.49 [95% CI, 0.29-0.83]), but this association occurred for only the later of 2 periods studied (2006-2013 and not 1999-2005). No other statistically significant benefits were reported overall. No study reported statistically significant harms (multiple gestation, autism, and maternal cancer) associated with pregnancy-related folic acid exposure.
CONCLUSIONS AND RELEVANCE
New evidence from observational studies provided additional evidence of the benefit of folic acid supplementation for preventing neural tube defects and no evidence of harms related to multiple gestation, autism, or maternal cancer. The new evidence was consistent with previously reviewed evidence on benefits and harms.
Topics: Female; Humans; Pregnancy; Autism Spectrum Disorder; Dietary Supplements; Folic Acid; Neural Tube Defects; Randomized Controlled Trials as Topic; Pregnancy Complications; Risk; Preconception Care; Prenatal Care
PubMed: 37526714
DOI: 10.1001/jama.2023.9864 -
Nature Feb 2024The loss of the tail is among the most notable anatomical changes to have occurred along the evolutionary lineage leading to humans and to the 'anthropomorphous apes',...
The loss of the tail is among the most notable anatomical changes to have occurred along the evolutionary lineage leading to humans and to the 'anthropomorphous apes', with a proposed role in contributing to human bipedalism. Yet, the genetic mechanism that facilitated tail-loss evolution in hominoids remains unknown. Here we present evidence that an individual insertion of an Alu element in the genome of the hominoid ancestor may have contributed to tail-loss evolution. We demonstrate that this Alu element-inserted into an intron of the TBXT gene-pairs with a neighbouring ancestral Alu element encoded in the reverse genomic orientation and leads to a hominoid-specific alternative splicing event. To study the effect of this splicing event, we generated multiple mouse models that express both full-length and exon-skipped isoforms of Tbxt, mimicking the expression pattern of its hominoid orthologue TBXT. Mice expressing both Tbxt isoforms exhibit a complete absence of the tail or a shortened tail depending on the relative abundance of Tbxt isoforms expressed at the embryonic tail bud. These results support the notion that the exon-skipped transcript is sufficient to induce a tail-loss phenotype. Moreover, mice expressing the exon-skipped Tbxt isoform develop neural tube defects, a condition that affects approximately 1 in 1,000 neonates in humans. Thus, tail-loss evolution may have been associated with an adaptive cost of the potential for neural tube defects, which continue to affect human health today.
Topics: Animals; Humans; Mice; Alternative Splicing; Alu Elements; Disease Models, Animal; Evolution, Molecular; Genome; Hominidae; Introns; Neural Tube Defects; Phenotype; Protein Isoforms; T-Box Domain Proteins; Tail; Exons
PubMed: 38418917
DOI: 10.1038/s41586-024-07095-8 -
JAMA Aug 2023
Topics: Humans; Folic Acid; Food, Fortified; Neural Tube Defects
PubMed: 37526731
DOI: 10.1001/jama.2023.12376 -
Trends in Endocrinology and Metabolism:... Sep 2023Changes in maternal nutrient availability due to diet or disease significantly increase the risk of neural tube defects (NTDs). Because the incidence of metabolic... (Review)
Review
Changes in maternal nutrient availability due to diet or disease significantly increase the risk of neural tube defects (NTDs). Because the incidence of metabolic disease continues to rise, it is urgent that we better understand how altered maternal nutrient levels can influence embryonic neural tube development. Furthermore, primary neurulation occurs before placental function during a period of histiotrophic nutrient exchange. In this review we detail how maternal metabolites are transported by the yolk sac to the developing embryo. We discuss recent advances in understanding how altered maternal levels of essential nutrients disrupt development of the neuroepithelium, and identify points of intersection between metabolic pathways that are crucial for NTD prevention.
Topics: Humans; Female; Pregnancy; Folic Acid; Neural Tube; Neurulation; Placenta; Neural Tube Defects
PubMed: 37468429
DOI: 10.1016/j.tem.2023.06.005 -
Advances and Technical Standards in... 2024Open spina bifida, also known as myelomeningocele (MMC), is the most challenging and severe birth defect of the central nervous system compatible with life and it is due... (Review)
Review
Open spina bifida, also known as myelomeningocele (MMC), is the most challenging and severe birth defect of the central nervous system compatible with life and it is due to a failure in the dorsal fusion of the nascent neural tube during embryonic development. MMC is often accompanied by a constellation of collateral conditions, including hydrocephalus, Arnold - Chiari II malformation, brainstem disfunction, hydrosyringomyelia, tethered cord syndrome and scoliosis. Beyond early surgical repair of the dorsal defect, MMC requires lifelong cares. Several additional surgical procedures are generally necessary to improve the long-term outcomes of patients affected by MMC and multidisciplinary evaluations are crucial for early identification and management of the various medical condition that can accompany this pathology. In this chapter, the most common pathological entities associated with MMC are illustrated, focusing on clinical manifestations, treatment strategies and follow up recommendations.
Topics: Humans; Meningomyelocele; Neurosurgical Procedures
PubMed: 38700682
DOI: 10.1007/978-3-031-42398-7_6 -
Trends in Molecular Medicine Dec 2023Chiari malformation type 1 (CM1) is the most common structural brain disorder involving the craniocervical junction, characterized by caudal displacement of the... (Review)
Review
Chiari malformation type 1 (CM1) is the most common structural brain disorder involving the craniocervical junction, characterized by caudal displacement of the cerebellar tonsils below the foramen magnum into the spinal canal. Despite the heterogeneity of CM1, its poorly understood patho-etiology has led to a 'one-size-fits-all' surgical approach, with predictably high rates of morbidity and treatment failure. In this review we present multiplex CM1 families, associated Mendelian syndromes, and candidate genes from recent whole exome sequencing (WES) and other genetic studies that suggest a significant genetic contribution from inherited and de novo germline variants impacting transcription regulation, craniovertebral osteogenesis, and embryonic developmental signaling. We suggest that more extensive WES may identify clinically relevant, genetically defined CM1 subtypes distinguished by unique neuroradiographic and neurophysiological endophenotypes.
Topics: Humans; Arnold-Chiari Malformation; Foramen Magnum; Brain Diseases; Human Genetics; Magnetic Resonance Imaging
PubMed: 37802664
DOI: 10.1016/j.molmed.2023.08.013