Polymorphic variants of genes involved in homocysteine metabolism in celiac disease

Sulfur-containing amino acids and risk of schizophrenia

BACKGROUND

Schizophrenia is a chronic and complex severe psychiatric disorder. Male and female are different in their risks for schizophrenia for the biologic and sociocultural reasons. Homocysteine (Hcy), Cysteine (Cys), and methionine (Met) play important roles in metabolism, and the three amino acids may also be involved in pathogenesis of schizophrenia.

OBJECTIVE

This study aimed to test the associations between sulfur-containing amino acid blood levels and risk of schizophrenia, evaluating the different risk in male and female.

METHODS

We organized a case-control study on 876 individuals with schizophrenia and 913 age- and sex-matched healthy subjects as control group. The concentrations of Hcy, Cys and Met were measured by liquid chromatography-tandem mass spectrometry technology. Subsequently, restricted cubic spline was applied to explore full-range associations of these amino acids with schizophrenia. Interactions between levels of the three amino acids and sex on additive scale were also tested.

RESULTS

Hcy levels at ≤29 μmol/L were associated with sharply increased risk of schizophrenia, inversely, Met was associated with sharply decreased risk of schizophrenia at levels ≤22 μmol/L. Increased Cys levels were associated with decreased risk of schizophrenia. Almost inverse associations were observed between Cys/Hcy and Met/Hcy ratios and schizophrenia. Significant synergistic interactions between levels of all the three amino acids and sex were discovered on an additive scale.

CONCLUSIONS

Our study suggests a close association between sulfur-containing amino acids and schizophrenia with different risk in male and female. Future studies are demanded to clarify the pathogenic role of Hcy, Cys and Met in schizophrenia.

Mean platelet volume modifies the contribution of homocysteine to cardiovascular disease: A real-world study

BACKGROUND AND AIMS

The effect of reductions in homocysteine (Hcy) on cardiovascular disease (CVD) was suggested to be modified by platelet activation, but the interaction between Hcy and platelet activation on CVD events is not well studied. Here, we aimed to examine the interaction between Hcy and platelet activation on CVD in a large, real-world population.

METHODS AND RESULTS

A total of 27,234 patients with hypertension (mean 63 years, 48% male) who were registered in Taicang city and free of CVD were prospectively followed up for new CVD events from 2017 to 2020. Hcy and platelet indices including mean platelet volume (MPV) were assayed at baseline. A total of 1063 CVD events were recorded during follow-up. Hcy at baseline was significantly associated with a higher risk of CVD (HR = 1.85, P < 0.001 for log-transformed Hcy). MPV showed a significant interaction effect with Hcy on CVD (HR = 1.20, P = 0.030 for the interaction term). The association between Hcy and CVD was significantly stronger in participants with a large (vs. small) MPV (HR = 2.71 vs. 1.32, P = 0.029 for log-transformed Hcy). For participants with both elevated Hcy and a large MPV, the attributable proportion of CVD events due to their interaction was 0.26 (95% CI: 0.06-0.45).

CONCLUSIONS

The association between Hcy and CVD was significantly stronger in patients with hypertension with a larger MPV. MPV may modify the contribution of Hcy to CVD events through synergistic interactions with Hcy. These findings suggest that MPV could be monitored and controlled in the prevention of CVD.

Folate metabolizing gene polymorphisms and genetic vulnerability to preterm birth in Korean women

BACKGROUND

The folate metabolism that converts homocysteine to methionine is closely related to the accumulation of homocysteine. Increased homocysteine levels lead to an impaired antithrombotic function of the vascular endothelium and uterine-placental circulation, resulting in abnormal pregnancy outcomes. Previous studies have reported that gene polymorphisms in folate metabolism are associated with the development of preterm birth (PTB) in various populations.

OBJECTIVE

we performed a case-control study to evaluate the association between five polymorphisms in folate metabolic genes (MTHFR, MTR, MTRR, TCN2) and PTB.

METHODS

In this study, a total of 254 subjects were analyzed (111 patients with PTB and 143 women at ≥ 38 weeks of gestation). Genotype and allele frequency differences between patients and control groups and the Hardy-Weinberg equilibrium were assessed using a Chi-square test. For evaluation indicators, odds ratios (ORs) of 95% confidence intervals (CI) were estimated. In addition, we analyzed the combined genotype frequencies of SNPs of folate-metabolizing genes to measure gene-gene interactions for PTB.

RESULTS

Our results showed that the MTR rs1805087 GG (p = 0.031), and TCN2 rs1801198 CG genotype (OR 0.53, 95% CI 0.288-0.980, p = 0.042) were significantly associated with PTB. The MTHFR rs4846049 AA showed a marginal trend toward significance (OR 0.15, 95% CI 0.018-1.205, p = 0.041). In particular, the combined genotypes, including MTHFR rs1537514 CC-MTRR rs1801394 GG, MTHFR rs1537514 CC-TCN2 rs1801198 CG, and MTR rs1805087 AA-TCN2 rs1801198 CG, have significant interactions with PTB (OR 0.49, 95% CI 0.248-0.992, p < 0.05).

CONCLUSION

The polymorphisms of folate metabolic genes may have a genetic association with the development of PTB in Korean women. A larger sample set and functional studies are required to further elucidate our findings.

Thromboembolic complications and cardiovascular events associated with celiac disease

Celiac disease (CD) is a chronic intestinal immune-mediated disease occurring in genetically susceptible individuals who are exposed to gluten. Although it primarily affects the small intestine, CD has been associated with a wide spectrum of extraintestinal manifestations, including thromboembolism and cardiovascular events. The risk of ischemic stroke, myocardial infarction, and thromboembolism, such as deep vein thrombosis and pulmonary embolism, is higher in patients with CD, while there is accumulating evidence that gluten-free diet in CD patients decreases the risk of these complications. The pathogenetic mechanism of increasing hypercoagulability in CD is multifactorial and involves hyperhomocysteinemia due to malabsorption of vitamins B12, B6, and folic acid; endothelial dysfunction; acceleration of atherosclerosis; chronic inflammation; thrombocytosis; and thrombophilia. Therefore, in cases of thromboembolic complications and cardiovascular disease of obscure etiology, clinicians' awareness of possible celiac disease is warranted.

The Prevalence of Celiac Disease in Children With Arterial Ischemic Stroke

OBJECTIVE

The association between arterial ischemic stroke (AIS) and celiac disease (CD) has been described in only a few cases in adults and children. We aim to determine the prevalence of CD in children and adolescents with AIS.

STUDY DESIGN

We investigated serum levels of tissue transglutaminase antibody immunoglobulin (Ig)A and total IgA from 76 children with AIS and in a healthy control group of 102 children. Study participants who were positive for tissue transglutaminase IgA antibodies underwent a duodenal biopsy.

RESULTS

A total of 2 patients in the AIS group (2.26%) and 2 in the control group (1.96%) had positive serum tissue transglutaminase antibody (P=0.89; 95% confidence interval, -5.05 to 6.89). Duodenal biopsy confirmed CD in only 1 patient who had AIS.

CONCLUSIONS

In the present study, children with acute arterial stroke did not exhibit a higher prevalence rate of CD compared with healthy controls. Therefore, the screening test for CD is not a necessary part of the management of AIS in children. However, cases of recurrent AIS could be examined for CD.

Role of Homocysteine in the Ischemic Stroke and Development of Ischemic Tolerance

Homocysteine (Hcy) is a toxic, sulfur-containing intermediate of methionine metabolism. Hyperhomocysteinemia (hHcy), as a consequence of impaired Hcy metabolism or defects in crucial co-factors that participate in its recycling, is assumed as an independent human stroke risk factor. Neural cells are sensitive to prolonged hHcy treatment, because Hcy cannot be metabolized either by the transsulfuration pathway or by the folate/vitamin B12 independent remethylation pathway. Its detrimental effect after ischemia-induced damage includes accumulation of reactive oxygen species (ROS) and posttranslational modifications of proteins via homocysteinylation and thiolation. Ischemic preconditioning (IPC) is an adaptive response of the CNS to sub-lethal ischemia, which elevates tissues tolerance to subsequent ischemia. The main focus of this review is on the recent data on homocysteine metabolism and mechanisms of its neurotoxicity. In this context, the review documents an increased oxidative stress and functional modification of enzymes involved in redox balance in experimentally induced hyperhomocysteinemia. It also gives an interpretation whether hyperhomocysteinemia alone or in combination with IPC affects the ischemia-induced neurodegenerative changes as well as intracellular signaling. Studies document that hHcy alone significantly increased Fluoro-Jade C- and TUNEL-positive cell neurodegeneration in the rat hippocampus as well as in the cortex. IPC, even if combined with hHcy, could still preserve the neuronal tissue from the lethal ischemic effects. This review also describes the changes in the mitogen-activated protein kinase (MAPK) protein pathways following ischemic injury and IPC. These studies provide evidence for the interplay and tight integration between ERK and p38 MAPK signaling mechanisms in response to the hHcy and also in association of hHcy with ischemia/IPC challenge in the rat brain. Further investigations of the protective factors leading to ischemic tolerance and recognition of the co-morbid risk factors would result in development of new avenues for exploration of novel therapeutics against ischemia and stroke.

Choline metabolic pathway gene polymorphisms and risk for Down syndrome: An association study in a population with folate-homocysteine metabolic impairment

BACKGROUND/OBJECTIVES

Choline is an essential nutrient involved in one-carbon metabolism, but its role in mechanisms underlying meiotic non-disjunction is poorly known. The relationship between folate-homocysteine metabolic pathway gene polymorphism and Down syndrome (DS) risk has been widely analyzed, but there are limited reports on its correlation with choline metabolism. In the present case-control association study, we investigated the relationship of three single-nucleotide polymorphisms (SNPs) (phosphatidylethanolamine N-methyltransferase (PEMT) rs12325817, choline dehydrogenase (CHDH) rs12676 and homocysteine methyltransferase (BHMT) rs3733890) of choline metabolism with risk for DS.

SUBJECT/METHODS

Genotyping of 228 mothers of a down syndrome child (DSM) and 200 control mothers (CMs) for all SNPs was performed by PCR coupled with restriction fragment length polymorphism method.

RESULTS

A significantly increased risk for BHMT +742AA genotype with an odds ratio of 4.96 (95% confidence interval (CI): 1.66-14.88, P=0.0036) was observed. For PEMT rs12325817 and CHDH rs12676, no significant difference in allelic and genotypic frequencies was observed. In genotypic combination analysis considering PEMT -744GG/CHDH +432GG/BHMT +742GG as the reference combination, PEMT -744GC/CHDH +432GG/BHMT +742GG genotypic combination was significantly higher in DSM compared with that in CMs with an odds ratio of 2.061 (95% CI: 1.10-3.86, P=0.0342). We also observed an epistatic interaction between methylenetetrahydrofolate reductase (MTHFR) rs1801133 and choline metabolic pathway gene variants.

CONCLUSIONS

Our findings indicate impaired choline metabolism showing a greater risk for DS, especially in a population associated with homocysteine-folate impairment. Further studies are required to confirm our findings.

A Three-Way Interaction among Maternal and Fetal Variants Contributing to Congenital Heart Defects

Congenital heart defects (CHDs) develop through a complex interplay between genetic variants, epigenetic modifications, and maternal environmental exposures. Genetic studies of CHDs have commonly tested single genetic variants for association with CHDs. Less attention has been given to complex gene-by-gene and gene-by-environment interactions. In this study, we applied a recently developed likelihood-ratio Mann-Whitney (LRMW) method to detect joint actions among maternal variants, fetal variants, and maternal environmental exposures, allowing for high-order statistical interactions. All subjects are participants from the National Birth Defect Prevention Study, including 623 mother-offspring pairs with CHD-affected pregnancies and 875 mother-offspring pairs with unaffected pregnancies. Each individual has 872 single nucleotide polymorphisms encoding for critical enzymes in the homocysteine, folate, and trans-sulfuration pathways. By using the LRMW method, three variants (fetal rs625879, maternal rs2169650, and maternal rs8177441) were identified with a joint association to CHD risk (nominal P-value = 1.13e-07). These three variants are located within genes BHMT2, GSTP1, and GPX3, respectively. Further examination indicated that maternal SNP rs2169650 may interact with both fetal SNP rs625879 and maternal SNP rs8177441. Our findings suggest that the risk of CHD may be influenced by both the intragenerational interaction within the maternal genome and the intergenerational interaction between maternal and fetal genomes.

Hypercoagulability in celiac disease--an update

Celiac disease is a life-long autoimmune disease affecting multiple organs of genetically susceptible individuals. One of the extra intestinal manifestations of the disease is thromboembolic events like strokes, veins' thrombosis, and pregnancy losses. Hypercoagulable autoimmune diseases like lupus erythematosus and antiphospholipid syndrome, associated with celiac disease just add risk to the patients. Pathogenic predisposing avenues increasing the hypercoagulability in celiac disease are multiple: nutritional deficiencies (B12, folate, and vitamin K), genetic predisposition (MTHFR mutations), thrombophilic autoantibodies, hyperhomocysinemia, endothelial dysfunction and platelet abnormalities. Primary pharmacologic thromboprophylaxis or treating the predisposing factors should be considered on a personal basis.

Severe heart failure, dilated cardiomyopathy and pulmonary haemosiderosis in coeliac disease: report of two cases

Coeliac disease (CD) is a chronic inflammatory, multi-system disorder with protean manifestations which has been linked to various auto-immune-mediated disorders. Dilated cardiomyopathy (DCM) is a rare extra-intestinal manifestation that is being recognised increasingly in patients with CD. Two cases of CD are described, an 18-year-old boy and a 13-year-old girl, both of whom presented with rapid onset of congestive heart failure and severe left ventricular systolic dysfunction. Upper limb venous thrombosis and recurrent haemoptysis secondary to pulmonary haemosiderosis in the second case were the other unusual features. The importance of CD screening of patients with DCM and pulmonary haemosiderosis is emphasised.

CBS c.844ins68 Polymorphism Frequencies in Control Populations: Implications on Nonsyndromic Cleft Lip With or Without Cleft Palate

INTRODUCTION

Nonsyndromic cleft lip with or without cleft palate (NSCLP) is a common birth defect with substantial clinical and social impact. Folate deficiency is one of the factors that have been associated with increased risk for NSCLP. Polymorphisms in folate and homocysteine pathway genes may act as susceptibility factors.

OBJECTIVE

The objective of this study was to evaluate prevalence estimates of cystathionine beta-synthase (CBS) insertion of 68-bp (c.844ins68) polymorphisms and their correlation with NSCLP.

MATERIAL AND METHODS

A total of 236 unrelated individuals from seven Indian populations and an additional 355 cases with NSCLP and 357 controls without NSCLP were included in this study. We investigated the CBS c.844ins68 polymorphism in all samples. Genotyping was performed with polymerase chain reaction and electrophoresis. The data were statistically analyzed using the chi-square test.

RESULTS

The CBS c.844ins68 allele is present in six of the seven populations analyzed, and allele frequencies range from 1.5% in Balija to 9.1% in Sugali populations. The CBS c.844ins68 polymorphism showed a significant protective effect on NSCLP at both genotype (WW versus WI: odds ratio [OR] = 0.54, 95% confidence interval [CI] = 0.31 to 0.95, P = .149) and allele levels (W versus I: OR = 0.56, 95% CI = 0.32 to 0.96, P = .033).

CONCLUSIONS

The current study observed significant differences in the frequency of the CBS 844ins68 allele across populations. There is a significant association between CBS c.844ins68 polymorphism and cleft lip and palate in the Indian population. Additional studies are warranted to identify the functional variants in the genes controlling homocysteine as etiological contributors to the formation of oral clefts.

Cystathionine beta-synthase deficiency heralded by cerebral sinus venous thrombosis and stroke

BACKGROUND

Elevated plasma homocysteine is a risk factor for arterial and venous thromboses in adults. Homocysteine is increased in cystathionine beta-synthase deficiency, a treatable amino acid metabolic disorder that may be missed on newborn screening placing children at risk of thrombosis and strokes.

PATIENT

We present a 3-year-old girl with normal newborn screening for cystathionine beta-synthase deficiency who developed a symptomatic cerebral venous sinus thrombosis. Subsequent testing revealed marked hyperhomocystinemia and genetic testing confirmed cystathionine beta-synthase deficiency.

CONCLUSIONS

Current newborn screening is limited in its ability to detect cystathionine beta-synthase deficiency and although postanalytical interpretation may provide increased sensitivity, a normal newborn screening result should not replace the importance of physician surveillance.

The role of hyperhomocysteinemia in neurological features associated with coeliac disease

Although a range of neurological and psychiatric disorders are widely reported to be associated with coeliac patients, their pathogenesis remains unclear. Some such disorders are believed to be secondary to vitamin deficiency due to malabsorption, others to immune mechanisms. We hypothesise that hyperhomocysteinemia might, by damaging the blood-brain barrier, expose neuronal tissue to all neuro-irritative metabolites, such as homocysteine itself, a neurotoxic excitatory and proconvulsant amino acid. Neurons respond to these stimuli through hyperexcitability, thereby predisposing subjects to neurological disorders such as epilepsy and headache. Furthermore, persisting endothelial damage may cause blood extravasation and subsequent deposition of calcium salts. We suggest that this might be the pathogenesis of the CEC syndrome, which is characterized by the association of coeliac disease, epilepsy and cerebral calcifications. Indeed, homocysteine plays a well-known role in cardiovascular endothelial dysfunction, with high serum and cerebrospinal fluid levels often being reported in coeliac patients. Moreover, data in the literature show a strong, growing association of homocysteine with epilepsy and migraine in non-coeliac subjects. Despite these findings, homocysteine has never been held directly responsible for neuronal functional features (neuronal hyperexcitability underlying epilepsy and migraine) and structural brain damage (expressed as cerebral calcification) in coeliac patients. Damage to the blood-brain barrier might also facilitate immune reactions against neuronal tissue to a considerable extent. This hypothesis combines the two afore-mentioned theories (vitamin deficiency due to malabsorption and immune mechanisms). We also wish to point out that no studies have yet investigated the prevalence of neuronal hyperexcitability and subclinical electroencephalic abnormalities in children and adults with newly-diagnosed coeliac disease before the introduction of a gluten-free diet, and in particular any changes following the introduction of the diet. We believe that the onset of clinical symptoms such as migraine and convulsions is preceded by a period in which damage is expressed exclusively by subclinical electroencephalic abnormalities; persisting damage to neuronal tissue subsequently leads to clinical manifestations. We propose two types of investigations: the first is to determine whether newly-diagnosed coeliac patients with hyperhomocysteinemia are a subgroup at risk for neurological features (clinical and subclinical); the second is to determine whether appropriate treatment of hyperhomocysteinemia and vitamin B status deficiency improves neurological abnormalities and reduces the risk of cerebral calcifications. The aim of these investigations is to develop new therapeutic strategies designed to prevent neuronal damage and increase the quality of life in children affected by such disorders.

Genetic predisposition for development of nephropathy in type 2 diabetes mellitus

The aim of the study was to explore the association of the angiotensin-converting enzyme (ACE) gene I/D polymorphism and the methylenetetrahydrofolate reductase (MTHFR) gene C677T polymorphism with development of diabetic nephropathy in type 2 diabetes mellitus. Three groups were recruited during 2007-2011: 232 normal controls, 185 type 2 diabetics without nephropathy, and 407 type 2 diabetics with nephropathy. The ACE I/D and MTHFR C677T polymorphisms were examined using PCR and PCR-RFLP methods. We found no significant association of the ACE I/D polymorphism with diabetic nephropathy in genotype, allele, dominant, and recessive models. We observed a significant association of MTHFR C677T with development of diabetic nephropathy in type 2 diabetics. The MTHFR C677T polymorphism plays a significant role in predisposition of renal insufficiency in diabetic patients.

Betaine-homocysteine methyltransferase 742G>A polymorphism and risk of down syndrome offspring in a Brazilian population

Down syndrome (DS) is the most common form of mental retardation of genetic etiology. Several polymorphisms in genes involved with the folic acid cycle have been associated to the risk of bearing a DS child; however, the results are controversial. Betaine-homocysteine methyltransferase (BHMT) is a key enzyme of folate pathway, and catalyzes the remethylation of homocysteine into methionine. Recent studies suggest that the polymorphism BHMT 742G>A may be associated with a decreased risk of having a DS child. We herein investigate the association of this polymorphism with the occurrence of DS in a Brazilian population. We have genotyped 94 mothers of DS infants (DSM) and 134 control mothers (CM) for this polymorphism through PCR-RFLP, and found significant differences for both BHMT 742G>A genotype (P=0.04) and allele (P=0.03) frequencies between DSM and CM. The observed genotypic frequencies were GG=0.45; GA=0.45 and AA=0.10 in CM, and GG=0.54; GA=0.38 and AA=0.02 in DSM. Allelic frequencies were G=0.68 and A=0.32 in CM and G=0.78 and A=0.22 in DSM. The presence of the mutant BHMT 742 A allele decreases 40% the risk of bearing a DS child (OR=0.61; 95% CI: 0.40-0.93; P=0.03), and the risk is diminished up to >80% in association with the homozygous genotype (OR=0.17; 95% CI: 0.04-0.80; P=0.01). Our results indicate that women harboring the single nucleotide polymorphism BHMT 742G>A have a decreased risk of a DS pregnancy, and further studies are necessary to confirm this protective effect.

The thrombophilic network of autoantibodies in celiac disease

BACKGROUND

Celiac disease is a life-long autoimmune condition, affecting genetically susceptible individuals that may present with thromboembolic phenomena. This thrombophilia represents a puzzle with multiple constituents: hyperhomocysteinemia, B12 and\or folate deficiency, methylenetetrahydrofolate reductase mutations, and protein C and S deficiency due to vitamin K deficiency. However, the well known thrombogenic factors, antiphosphatidylserine/prothrombin and antiprothrombin have never been explored in celiac disease.

METHODS

The serum autoantibody levels were determined in 248 individuals, classified into three groups. Group 1 comprised 70 children with definitive celiac disease (age: 7.04 ±4.3 years, male to female ratio 1.06) and group 2 comprised 88 normal children (age: 6.7 ±4.17 years, male to female ratio 0.87), representing controls. The pediatric populations were compared to group 3, which included 90 adults who were family members (parents) of group 1 (age: 34.6 ±11.35 years, male to female ratio 1.2). Antibodies were checked by enzyme-linked immunosorbent assay.

RESULTS

Mean optical density levels of serum antiphosphatidylserine/prothrombin immunoglobulin G antibodies were 32.4 ±19.4, 3.6 ±2.5 and 16.1 ±15.8 absorbance units in groups 1, 2 and 3 respectively (P <0.0001), with 45.7%, 0% and 7.8% of groups 1, 2 and 3 respectively positive for the antibody (P <0.01). Mean optical density levels of serum antiphosphatidylserine/prothrombin immunoglobulin M antibodies were 14.2 ±8.7, 6.7 ±6.4 and 12.4 ±15.5 absorbance units in groups 1, 2 and 3 respectively (P <0.0001), with 7.1%, 3.4% and 9.9% of groups 1, 2 and 3 positive for the antibody. Mean optical density levels of serum antiprothrombin and antiphospholipid immunoglobulin G antibodies were higher in groups 1 and 3 compared with 2 (P <0.005) and in groups 1 and 2 compared with 3 (P <0.01), respectively. Groups 1, 2 and 3 were positive for antiphospholipid immunoglobulin G antibodies (groups 1 and 2 compared with 3) . Celiac disease sera harbor a higher antiprothrombin immunoglobulin G level compared with controls.

CONCLUSIONS

It is suggested that the intestinal injury, endothelial dysfunction, platelet abnormality and enhanced apoptosis recently described in celiac disease are at the origin of the increased exposure of phospholipids or new epitopes representing autoantigens. Those autoantibodies might play a pathogenic role in the thrombophilia associated with celiac disease and represent markers for potential anticoagulant preventive therapy.

Recurrent ischemic strokes in a young celiac woman with MTHFR gene mutation

Celiac disease (CD) is frequently associated with neurological disorders, but very few reports concern the association with ischemic stroke. A 26-year-old woman affected by CD with secondary amenorrhea, carrier of a homozygous 5,10-methylenetetrahydrofolate reductase mutation with hyperhomocysteinemia, was affected by two occipital ischemic strokes within a period of 5 mo. At the time of the second stroke, while she was being treated with folic acid, acetylsalicylic acid and a gluten-free diet, she had left hemianopsia, left hemiparesthesias, and gait imbalance. Brain magnetic resonance imaging showed a subacute right occipital ischemic lesion, which was extended to the dorsal region of the right thalamus and the ipsilateral thalamo-capsular junction. Antitransglutaminase and deamidated gliadin peptide antibodies were no longer present, while antinuclear antibodies, antineuronal antibodies and immune circulating complexes were only slightly elevated. Since the patient was taking folic acid, her homocysteine ​​levels were almost normal and apparently not sufficient alone to explain the clinical event. A conventional cerebral angiography showed no signs of vasculitis. Finally, rare causes of occipital stroke in young patients, such as Fabry’s disease and mitochondrial myopathy, encephalomyopathy, lactic acidosis and stroke-like symptoms, were also excluded by appropriate tests. Thus, the most probable cause for the recurrent strokes in this young woman remained CD, although the mechanisms involved are still unknown. The two main hypotheses concern malabsorption (with consequent deficiency of vitamins known to exert neurotrophic and neuroprotective effects) and immune-mediated mechanisms. CD should be kept in mind in the differential diagnosis of ischemic stroke in young patients.