Cerebral folate deficiency: a treatable cause of late deterioration in epilepsy with developmental delay.

A 25-year-old woman with childhood-onset refractory epilepsy and developmental delay experienced a gradually progressive marked deterioration in mobility and seizure control, with language regression. Investigation identified a homozygous deletion within the contactin-associated protein-like 2 gene (CNTNAP2), underlying her early presentation, but also cerebral folate deficiency that most likely contributed to her later deterioration. Following antiseizure medication adjustment and treatment with folinic acid, she stabilised with improved seizure control and limited improvement in language and motor function; she has remained neurologically stable for more than a decade. That the previously observed neurological decline was halted by folinic acid replacement supports this being due to cerebral folate deficiency. Metabolic conditions are less well recognised in adults and can be under-diagnosed. They are potentially treatable and should be considered even in the presence of another cause, particularly when the presentation is not fully compatible.

Treatment variability and its relationships to outcomes among patients with Wernicke's encephalopathy: A multicenter retrospective study.

BACKGROUND: Despite guidelines and recommendations, Wernicke's encephalopathy (WE) treatment lacks evidence, leading to clinical practice variability. AIMS: Given the overall lack of information on thiamine use for WE treatment, we analyzed data from a large, well-characterized multicenter sample of patients with WE, examining thiamine dosages; factors associated with the use of different doses, frequencies, and routes; and the influence of differences in thiamine treatment on the outcome. METHODS: This retrospective study was conducted with data from 443 patients from 21 centers obtained from a nationwide registry of the Spanish Society of Internal Medicine (from 2000 to 2012). Discharge codes and Caine criteria were applied for WE diagnosis, and treatment-related (thiamine dosage, frequency, and route of administration) demographic, clinical, and outcome variables were analyzed. RESULTS: We found marked variability in WE treatment and a low rate of high-dose intravenous thiamine administration. Seventy-eight patients out of 373 (20.9%) received > 300mg/day of thiamine as initial dose. Patients fulfilling the Caine criteria or presenting with the classic WE triad more frequently received parenteral treatment. Delayed diagnosis (after 24h hospitalization), the fulfillment of more than two Caine criteria at diagnosis, mental status alterations, and folic acid deficiency were associated significantly with the lack of complete recovery. Malnutrition, reduced consciousness, folic acid deficiency, and the lack of timely thiamine treatment were risk factors for mortality. CONCLUSIONS: Our results clearly show extreme variability in thiamine dosages and routes used in the management of WE. Measures should be implemented to ensure adherence to current guidelines and to correct potential nutritional deficits in patients with alcohol use disorders or other risk factors for WE.

Folic Acid Supplementation to Prevent Neural Tube Defects: US Preventive Services Task Force Reaffirmation Recommendation Statement.

Importance: Neural tube defects are among the most common congenital malformations in the US, with an estimated 3000 pregnancies affected each year. Many of these neural tube defects are caused by low folate levels in the body. Objective: The US Preventive Services Task Force (USPSTF) commissioned a reaffirmation evidence update on the benefits and harms of folic acid supplementation. Population: Persons who are planning to or could become pregnant. Evidence Assessment: The USPSTF concludes that, for persons who are planning to or could become pregnant, there is high certainty that folic acid supplementation has a substantial net benefit to prevent neural tube defects in their offspring. Recommendation: The USPSTF recommends that all persons planning to or who could become pregnant take a daily supplement containing 0.4 to 0.8 mg (400 to 800 µg) of folic acid. (A recommendation).

Hypomyelination caused by a novel homozygous pathogenic variant in FOLR1: complete clinical and radiological recovery with oral folinic acid therapy and review of the literature.

BACKGROUND: Neurodegeneration due to cerebral folate transport deficiency is a rare autosomal recessive disorder caused by biallelic pathogenic variants in FOLR1. Onset typically occurs in late infancy and is characterized by psychomotor regression, epilepsy, and a hypomyelinating leukodystrophy on magnetic resonance imaging. If left untreated, progressive neurodegeneration occurs. However, early treatment with folinic acid has been shown to stabilize or reverse neurological features. Approximately thirty patients have been described worldwide. Here, we report the first two cases with genetically proven cerebral folate transport deficiency from South-Eastern Europe, describe the effect of oral folinic acid therapy on clinical and neuroradiological features and review the literature. RESULTS: Two siblings presented in childhood with clinical and radiological findings consistent with a hypomyelinating leukodystrophy. Exome sequencing revealed a novel homozygous pathogenic variant in FOLR1 (c.465_466delinsTG; p.W156G), confirming the diagnosis of neurodegeneration due to cerebral folate transport deficiency. Folinic acid treatment was promptly initiated in both patients. The younger sibling was treated early in disease course at 2 years of age, and demonstrated complete recovery in clinical and MRI features. The older sibling, who was 8 years of age at the time of diagnosis and treatment, demonstrated partial but substantial improvements. CONCLUSION: We present the first account in the literature that early treatment initiation with oral folinic acid alone can result in complete neurological recovery of both clinical and radiological abnormalities in neurodegeneration due to cerebral folate deficiency. Moreover, through the report of these patients along with review of the literature, we provide information about the natural history of the disease with comparison of treatment effects at different stages of disease progression. This report also reinforces the importance of universal access to genetic testing to ensure prompt diagnoses for treatable disorders.

Clinico-laboratory Profile and Outcomes of Megaloblastic Anemia presenting as Severe Pyrexial Illness mimicking Tropical Infection.

BACKGROUND: Anemia-causing fever has been described in patients with megaloblastic anemia. Although the exact mechanism of this is unknown, high-grade fever is relatively less reported. MATERIALS AND METHODS: This prospective observational study included all new cases of megaloblastic anemia presenting with febrile illness (>101°F) during a 3-year period. Patients with existing anemia, comorbidities, and other causes of macrocytosis were excluded. A detailed evaluation for megaloblastic anemia and workup for excluding tropical infections was done. The patients were treated with parenteral vitamin B12, folic acid, and other hematinics. RESULTS: Around 24 cases of megaloblastic anemia presenting with high-grade fever were included, with 14 (58.3%) males, mean duration of fever 7.7 days (4-18 days), and 09 (37.5%) having temperature >103°F. The mean hemoglobin (Hb) was 8.15 g/dL (3.7-11.1 g/dL), the mean corpuscular volume (MCV) was 111 ± 7.8 fL, 18 (75%) had unconjugated hyperbilirubinemia, the mean lactate dehydrogenase (LDH) was 814 ± 24 IU/L, and 21 (87.5%) had low B12 or folate levels. Most showed good therapeutic response to B12 or folic acid with defervescence in 1-5 days (mean 2.6 days) and improvement in lab parameters in 1 week. The study population was divided into those with temperature ≥103°F, and temperature <103°F it was seen that there was a significant association (p < 0.05) with leucocyte count of ≤3000/cumm, and MCV ≥110 fL, in patients with temperature ≥103°F Conclusion: Megaloblastic anemia should be considered in the differentials of a patient presenting with a febrile illness with no clinical localization and a negative initial fever workup. Early identification and prompt therapy of this easily treatable disorder are very essential.

Does maternal genetic liability to folate deficiency influence the risk of antiseizure medication-associated language impairment and autistic traits in children of women with epilepsy?

BACKGROUND: Prenatal exposure to antiseizure medication (ASM) may lead to low plasma folate concentrations and is associated with impaired neurodevelopment. OBJECTIVES: To examine whether maternal genetic liability to folate deficiency interacts with ASM-associated risk of language impairment and autistic traits in children of women with epilepsy. METHODS: We included children of women with and without epilepsy and with available genetic data enrolled in the Norwegian Mother, Father, and Child Cohort Study. Information on ASM use, folic acid supplement use and dose, dietary folate intake, child autistic traits, and child language impairment was obtained from parent-reported questionnaires. Using logistic regression, we examined the interaction between prenatal ASM exposure and maternal genetic liability to folate deficiency expressed as polygenic risk score of low folate concentrations or maternal rs1801133 genotype (CC or CT/TT) on risk of language impairment or autistic traits. RESULTS: We included 96 children of women with ASM-treated epilepsy, 131 children of women with ASM-untreated epilepsy, and 37,249 children of women without epilepsy. The polygenic risk score of low folate concentrations did not interact with the ASM-associated risk of language impairment or autistic traits in ASM-exposed children of women with epilepsy compared with ASM-unexposed children aged 1.5-8 y. ASM-exposed children had increased risk of adverse neurodevelopment regardless of maternal rs1801133 genotype {adjusted odds ratio [aOR] for language impairment aged 8 y was 2.88 [95% confidence interval (CI): 1.00, 8.26] if CC and aOR 2.88 [95% CI: 1.10, 7.53] if CT/TT genotypes}. In children of women without epilepsy aged 3 y, those with maternal rs1801133 CT/TT compared with CC genotype had increased risk of language impairment (aOR: 1.18; 95% CI: 1.05, 1.34). CONCLUSIONS: In this cohort of pregnant women reporting widespread use of folic acid supplements, maternal genetic liability to folate deficiency did not significantly influence the ASM-associated risk of impaired neurodevelopment.

Folate deprivation induced neuroinflammation impairs cognition.

Nutritional status is associated with many neurocognitive diseases. Folate is one of the micronutrients, and its deficiency is associated with clinical outcomes of neurological diseases. Nevertheless, molecular mechanism behind the folate deficiency induced neurological disorders are not well-known. We have hypothesized that folate-deficiency is a cardinal determinant responsible for manifestation of cognitive impairment through inflammation mediated neurodegenerative pathologies. Objective of the current study was to assess whether folate deficiency is associated with cognitive dysfunction or is merely an epiphenomenon and to identify the underlying mechanisms. We developed folate insufficient zebrafish model through intra-peritoneal treatment of methotrexate. T-maze test was carried to assess the spatial learning and memory of the fish. Higher latency of the folate-deprived zebrafishes in the T-maze test is a reflection of altered cognition. This result is supported by declined levels of dopamine and serotonin, neurotransmitters linked with learning and memory. Elevated IL-6 and CRP in peripheral blood, along with increased expression of NF-ĸB in brain indicates manifestation of neuroinflammation. Indeed, together with upregulation of maptb gene it can be implied that folate deficiency acts as a risk factor for neurodegeneration in the form of tauopathies. Furthermore, diminished localisation of synaptopodin, a protein linked to neural plasticity, suggests that neuroinflammation caused by folate deprivation hampers the plasticity of brain. Histological analysis of brain revealed the development of histopathological features including spongiform degeneration and neuronal loss in folate deprived condition. We thus conclude that folate deficiency results in NF-ĸB activation, which through multiple processes mediated by neuroinflammation could lead to cognitive decline.

Cerebral folate transporter deficiency: a potentially treatable neurometabolic disorder.

Cerebral folate deficiency (CFD) syndrome is a rare treatable neurometabolic disorder with low levels of the active form of folaten in cerebrospinal fluid (CSF) arising from different causes such as FOLR1 gene mutations or autoantibodies against the folate receptor-alpha (FR) protein that can block folate transport across the choroid plexus. It is characterized by late infantile onset refractory seizures, ataxia, movement disorder, and unexplained global developmental delay. Here, we report a patient diagnosed with autistic spectrum disorder, followed by refractory myoclonic-atonic seizures, ataxia, and loss of motor skills over time. A homozygous missense (c.665A > G) mutation in FOLR1 gene and extremely low CSF 5-methyltetrahydrofolate level led to the diagnosis of CFD. Although she was initiated on combined oral and intravenous high doses of folinic acid treatment at 6 years of age, mild improvement was achieved in terms of epileptic seizures and motor skills. It is important that CFD should be kept in mind in cases with refractory myoclonic-atonic seizure and folinic acid treatment should be started as soon as possible.

Combined action of SAMe, Folate, and Vitamin B12 in the treatment of mood disorders: a review.

Mood disorders affect more than 500 million people around the world. In the last decade, their prevalence has increased, and many people suffer from nervousness, anxiety, and stress at least once in their lives. The incidence of mood disorders and anxiety increases during perimenopause or under stressful conditions. The social restrictions introduced during the COVID-19 pandemic have significantly increased the normal burden of psychological and psychic disorders. In moderate to severe cases, pharmacological treatment is currently recommended, while in mild disorders, especially in the initial phase, psychological therapy is preferable. It is known that several nutrients are crucial for brain function. Among them, folate (vitamin B9), cyanocobalamin (vitamin B12), and S-adenosyl-L-methionine (SAMe) have been shown to influence various neurobiological processes. Overall, the available evidence suggests that dietary supplementation with folic acid, vitamin B12, and SAMe can be beneficial for people with mild mood disorders.

Serum folate deficiency and the risks of dementia and all-cause mortality: a national study of old age.

BACKGROUND: The association between serum folate deficiency and the risk of dementia in old age is unclear, perhaps owing to small sample sizes, the competing risk of mortality or reverse causation. OBJECTIVE: To examine the associations between serum folate deficiency and the risks of incident dementia and all-cause mortality in a large national sample of older adults. METHODS: A prospective cohort aged 60-75 years (n=27 188) without pre-existing dementia for at least 10 years, was tested for serum concentrations of folate and followed up for dementia or all-cause mortality. Serum folate deficiency was classified as present (<4.4 ng/mL), otherwise absent. HRs and 95% CIs from competing risks Cox models were fitted to quantify the associations between serum folate deficiency and the risks of dementia and all-cause mortality. To examine reverse causation, the analysis was stratified by duration of follow-up. FINDINGS: The presence compared with the absence of serum folate deficiency was associated with higher risks of dementia (HR=1.68; 95% CI 1.32 to 2.13; p<0.001) and all-cause mortality (HR=2.98; 95% CI 2.52 to 3.52; p<0.001). Evidence for reverse causation were moderate for dementia and mild for all-cause mortality. CONCLUSIONS: Serum concentrations of folate may function as a biomarker used to identify those at risk of dementia and mortality; however, reverse causation is likely. Further research is needed to examine the role of serum folate deficiency in dementia aetiology. CLINICAL IMPLICATIONS: Serum folate deficiency in older adults requires monitoring and treatment for preventative measures and/or as part of implemented therapeutic strategies.

Folate Deficiency in an Urban Safety Net Population.

PURPOSE: Since mandatory fortification of grain products with folic acid in the United States in 1998, folate deficiency has become rare. Some have suggested that serum folate levels should be tested rarely in countries with mandatory folic acid fortification, given low rates of deficiency, high cost per deficiency diagnosis, and low rates of supplementation for those diagnosed as deficient. Given persistent racial, ethnic, and socioeconomic disparities in folate deficiency, these suggestions may not apply to all populations. We examine the rate at which serum testing detected folate deficiency in an urban safety net hospital and the characteristics of folate-deficient patients. METHODS: We reviewed the charts of all inpatients and emergency department patients with low serum folate results at a safety net hospital in Boston in 2018. We collected data concerning demographics, social determinants of health, clinical factors, and whether folate supplementation was prescribed. Finally, we performed a cost analysis. RESULTS: Of 1368 patients tested, 76 (5.5%) met criteria for folate deficiency. Overall, 86.8% of these patients were anemic, and 17.1% had macrocytic anemia; 42% were diagnosed with malnutrition. Common social determinants in folate-deficient patients included birth outside of the United States, homelessness, and alcohol use disorder. Of folate-deficient patients, 88% were newly prescribed folic acid supplementation at discharge. The estimated charge per deficient test was $1278. CONCLUSION: Compared with a nearby institution, serum folate testing at our safety net hospital detected deficiency at a higher rate, incurred a lower charge per deficient test, and was more likely to impact management.

Hyperhomocysteinemia-related serum metabolome alterations not normalized by short-term folic acid treatment.

INTRODUCTION: Hyperhomocysteinemia (HHCys) is an independent risk factor for various diseases such as cardiovascular diseases, Alzheimer's, and cancers. Folate deficiency is one of the significant reasons for HHCys. However, it is not known whether folate deficiency with HHCys is associated with any serum metabolites. OBJECTIVES: Our objective was to identify the metabolic alterations in people having folate deficiency with HHCys and check whether a short-term folic acid therapy could reverse those metabolic changes. METHODS: The study enrolled 34 participants aged between 18 and 40 years having folate deficiency (< 4.6 ng/mL) with HHCys (> 15 µmol/L) and 21 normal healthy individuals. A short-term intervention of oral folic acid (5 mg/day) was done in the HHCys group for 30 days. Untargeted metabolomics analysis of serum was performed in all study subjects before and after the folic acid treatment. Different univariate methods and the multivariable-adjusted linear regression models were employed to determine an association between homocysteine level and metabolite profile. RESULTS: Metabolomics analysis data showed that many metabolites involved in the biochemical pathways of lipid metabolisms such as polyunsaturated fatty acids, glycerolipids, and phospholipids were downregulated in the HHCys group. Short-term oral folic acid therapy significantly reduced their serum homocysteine level. However, the metabolic pathway alterations observed in folate-deficient HHCys-condition were unaltered even after the folic acid treatment. CONCLUSIONS: Our study revealed that people who have a folic acid deficiency with HHCys have an altered metabolite profile related to lipid metabolism, which cannot be reversed by short-term folic acid therapy.

The effects of folate and iron deficiency followed by supplementation on blood morphology and inflammation biomarkers in rats.

BACKGROUND: Little is known about the relation between iron and folic acid (FA) supplementation and inflammation. The aim of this study was to evaluate the effects of iron and folate deficiency and supplementation on blood morphology parameters, and to assess the role of iron and folate transporters in inflammation. METHODS: A four-week period of FA and iron deficiency in Wistar rats was followed by randomization into a group fed with a diet deficient in FA and supplemented with Fe (DFE), a group fed a diet deficient in Fe and supplemented with FA (DFOL), a group fed a diet supplemented with Fe and FA (FEFOL), a group fed a diet deficient in Fe and FA (D), and a group fed a control diet (C). The blood Crp concentration and blood count were determined. The expression of SLC11A2, SLC46A1, SLC19A1, and TFR2 proteins was assessed using the western blot method. RESULTS: After ten days on the experimental diets, the rats in the DFOL group had a 21% higher concentration of white blood cells (WBC) than the FEFOL group did (p < 0.05). We did not observe any differences between the groups in terms of C-reactive protein (Crp) concentration. We also did not find any other differences between the groups in other morphological parameters. Analysis of the correlation between blood count parameters and the expression of iron and folate transporters gave conflicting results. CONCLUSIONS: To conclude, iron and folate supplementation may affect WBC concentration in the blood.

Epidemiology and (Patho)Physiology of Folic Acid Supplement Use in Obese Women before and during Pregnancy.

Preconception folic acid supplement use is a well-known method of primary prevention of neural tube defects (NTDs). Obese women are at a higher risk for having a child with a NTD. As different international recommendations on folic acid supplement use for obese women before and during pregnancy exist, this narrative review provides an overview of epidemiology of folate deficiency in obese (pre)pregnant women, elaborates on potential mechanisms underlying folate deficiency, and discusses considerations for the usage of higher doses of folic acid supplements. Women with obesity more often suffer from an absolute folate deficiency, as they are less compliant to periconceptional folic acid supplement use recommendations. In addition, their dietary folate intake is limited due to an unbalanced diet (relative malnutrition). The association of obesity and NTDs also seems to be independent of folate intake, with studies suggesting an increased need of folate (relative deficiency) due to derangements involved in other pathways. The relative folate deficiency, as a result of an increased metabolic need for folate in obese women, can be due to: (1) low-grade chronic inflammation (2) insulin resistance, (3) inositol, and (4) dysbiotic gut microbiome, which plays a role in folate production and uptake. In all these pathways, the folate-dependent one-carbon metabolism is involved. In conclusion, scientific evidence of the involvement of several folate-related pathways implies to increase the recommended folic acid supplementation in obese women. However, the physiological uptake of synthetic folic acid is limited and side-effects of unmetabolized folic acid in mothers and offspring, in particular variations in epigenetic (re)programming with long-term health effects, cannot be excluded. Therefore, we emphasize on the urgent need for further research and preconception personalized counseling on folate status, lifestyle, and medical conditions.

[Chorioretinal atrophy in pediatric cerebral folate deficiency-a preventable disease?] / Chorioretinale Atrophie bei kindlichem zerebralem Folatmangel ­ eine vermeidbare Erkrankung?

Cerebral folate deficiency (CFD) results in neurological alterations and a massive degeneration of the choroid/retina if left untreated, which limit the visual field and visual acuity. This article reports the case of a female patient with CFD, who developed autistic personal characteristics prior to reaching school age and first started to speak at the age of 3 years. At the age of 6 years she was presented because of unclear reduced visual acuity in the right eye. At that time mild bilateral peripheral chorioretinal atrophy was present, which subsequently became more pronounced. Additionally, a centrally emphasized chorioretinal atrophy further developed. Visual acuity of both eyes progressively deteriorated until stagnating at 0.1 at the age of 14 years. The causal assignment of the findings of the patient was not possible for many years. Choroideremia was excluded by molecular genetic testing (CHM gene with no mutations) and gyrate atrophy was ruled out by a normal ornithine level. The existence of a mitochondrial disease was almost completely excluded by exome sequencing. After the onset of further nonocular symptoms, e.g. neuromuscular disorders, electroencephalograph (EEG) alterations and autistic disorder, intensified laboratory diagnostics were performed in the treating pediatric hospital. Finally, an extremely low level of the folic acid metabolite 5­methyltetrahydrofolate was detected in the cerebrospinal fluid (CSF) leading to the diagnosis of CFD. High-dose substitution treatment with folic acid was subsequently initiated. After excluding the presence of a pathogenic mutation of the FOLR1 gene for the cerebral folate receptor 1, a high titer blocking autoantibody against cerebral folate receptor 1 was detected as the cause.

Treatable Cause of Pancytopenia, Recurrent Infections and Refractory Epilepsy: Secondary to Hereditary Folate Malabsorption (HFM) Due to Novel Pathogenic Variant.

Hereditary folate malabsorption (HFM) is a rare disorder of proton-coupled folate transporter deficiency. It is characterized by macrocytic anemia, recurrent infections, and epilepsy. A five-year-old girl presented with recurrent pneumonia, diarrhea, and mouth ulcers. On examination, pallor, microcephaly with spastic quadriparesis was noted. On investigations, leukopenia and thrombocytopenia with megaloblastic bone marrow picture and low folate levels was found. HFM was diagnosed at two years of age and the child was treated with folinic acid. Her diagnosis was confirmed by whole-exome sequencing which revealed a novel pathogenic homozygous frameshift insertion variation (c.620dupG) in the exon 2 of the SLC46A1 gene which was further confirmed by Sanger sequencing. The child improved significantly except for a partial improvement in neurological symptoms.

Maternal folate levels during pregnancy and offspring brain development in late childhood.

BACKGROUND: Cumulative evidence shows that low maternal folate levels during pregnancy are associated with offspring neuropsychiatric disorders even in the absence of neural tube defects. However, the relationship between prenatal exposure to folate and brain development in late childhood has been rarely investigated. METHODS: In 2095 children from a prospective population-based cohort in Rotterdam, the Netherlands, we examined the association of maternal folate levels during pregnancy with downstream brain development in offspring. Maternal folate concentrations were measured from venous blood in early gestation. Child structural neuroimaging data were measured at age 9-11 years. In addition, measures of child head circumference using fetal ultrasound in the third trimester and total brain volume using magnetic resonance imaging at age 6-8 years were used for analyses with repeated assessments of brain development. RESULTS: Maternal folate deficiency (i.e., <7 nmol/L) during pregnancy was associated with smaller total brain volume (B = -18.7 cm3, 95% CI -37.2 to -0.2) and smaller cerebral white matter (B = -7.2 cm3, 95% CI -11.8 to -2.6) in children aged 9-11 years. No differences in cortical thickness or surface area were observed. Analysis of the repeated brain assessments showed that children exposed to deficient folate concentrations in utero had persistently smaller brains compared to controls from the third trimester to childhood (ß = -0.4, 95% CI -0.6 to -0.1). CONCLUSIONS: Low maternal folate levels during pregnancy are associated with altered offspring brain development in childhood, suggesting the importance of essential folate concentrations in early pregnancy.

First case report of cerebral folate deficiency caused by a novel mutation of FOLR1 gene in a Chinese patient.

BACKGROUND: Cerebral folate deficiency (CFD) is a neurological disease, hallmarked by remarkable low concentrations of 5-methyltetrahydrofolic acid (5-MTHF) in cerebrospinal fluid (CSF). The primary causes of CFD include the presence of folate receptor (FR) autoantibodies, defects of FR encoding gene FOLR1, mitochondrial diseases and congenital abnormalities in folate metabolism. CASE PRESENTATION: Here we first present a Chinese male CFD patient whose seizure onset at 2 years old with convulsive status epilepticus. Magnetic Resonance Imaging (MRI) revealed the development of encephalomalacia, laminar necrosis in multiple lobes of the brain and cerebellar atrophy. Whole Exome Sequencing (WES) uncovered a homozygous missense variant of c.524G > T (p.C175F) in FOLR1 gene. Further laboratory tests demonstrated the extremely low level of 5-MTHF in the CSF from this patient, which was attributed to cerebral folate transport deficiency. Following the intravenous and oral treatment of calcium folinate, the concentrations of 5-MTHF in CSF were recovered to the normal range and seizure symptoms were relieved as well. CONCLUSIONS: One novel variation of FOLR1 was firstly identified from a Chinese male patient with tonic-clonic seizures, developmental delay, and ataxia. The WES and laboratory results elucidated the etiology of the symptoms. Clinical outcomes were improved by early diagnosis and proper treatment.

Treatment of Folate Metabolism Abnormalities in Autism Spectrum Disorder.

Autism spectrum disorder (ASD) is a heterogeneous neurodevelopmental disorder that currently has no approved medical therapy to address core symptoms or underling pathophysiological processes. Several compounds are under development that address both underlying pathophysiological abnormalities and core ASD symptoms. This article reviews one of these treatments, d,l-leucovorin calcium (also known as folinic acid) for treatment of folate pathway abnormalities in children with ASD. Folate is a water-soluble B vitamin that is essential for normal neurodevelopment and abnormalities in the folate and related pathways have been identified in children with ASD. One of these abnormalities involves a partial blockage in the ability of folate to be transported into the brain utilizing the primary transport mechanism, the folate receptor alpha. Autoantibodies which interfere with the function of the folate receptor alpha called folate receptor alpha autoantibodies have been identified in 58%-76% of children with ASD and independent studies have demonstrated that blood titers of these autoantibodies correlate with folate levels in the cerebrospinal fluid. Most significantly, case-series, open-label, and single and double-blind placebo-controlled studies suggest that d,l-leucovorin, a reduced folate that can bypass the blockage at the folate receptor alpha by using the reduced folate carrier, an alternate pathway, can substantially improve particular symptoms in children with ASD, especially those positive for folate receptor alpha autoantibodies. This article reviews the current evidence for treating core and associated symptoms and underlying pathophysiological mechanisms in children with ASD with d,l-leucovorin.