West Syndrome in an Infant With Vitamin B12 Deficiency Born to Autoantibodies Positive Mother

Vitamin B12 responsive developmental and epileptic encephalopathy due to a novel mutation in the FUT2 gene: a case report

BACKGROUND

Vitamin B12 deficiency is a recognised cause of neurological manifestations, including peripheral neuropathy, behavioural changes, and seizures. However, developmental and epileptic encephalopathy due to vitamin B12 deficiency is very rare. Here, we report an infant with vitamin B12-responsive developmental and epileptic encephalopathy due to a novel mutation in the fucosyltransferase 2 (FUT2) gene responsible for vitamin B12 absorption.

CASE PRESENTATION

An 11-month-old girl of non-consanguineous parents presented with recurrent episodes of seizures since four months. Her seizures started as flexor epileptic spasms occurring in clusters resembling infantile epileptic spasms syndrome with hypsarrhythmia in the electroencephalogram. She was treated with multiple drugs, including high-dose prednisolone, vigabatrin, sodium valproate, levetiracetam and clobazam, without any response, and she continued to have seizures at 11 months. She had an early developmental delay with maximally achieving partial head control and responsive smile at four months. Her development regressed with the onset of seizure; at 11 months, her developmental age was below six weeks. On examination, she was pale and had generalised hypotonia with normal muscle power and reflexes. Her full blood count and blood picture revealed macrocytic anaemia with oval and round macrocytes. Bone marrow aspiration showed hypercellular marrow erythropoiesis with normoblastic and megaloblastic maturation. Due to the unusual association of refractory epilepsy and megaloblastic anaemia, a rare genetic disease of the vitamin B12 or folate pathways was suspected. The whole exome sequencing revealed a homozygous missense variant in exon 2 of the FUT2 gene associated with reduced vitamin B12 absorption and low plasma vitamin B12 levels, confirming the diagnosis of vitamin B12 deficiency related developmental and epileptic encephalopathy. She was started on intramuscular hydroxocobalamin, for which she showed a marked response with reduced seizure frequency.

CONCLUSION

We report a novel variant in the FUT2 gene associated with vitamin B12-responsive developmental and epileptic encephalopathy and megaloblastic anaemia. This case report highlights the importance of timely genetic testing in children with refractory developmental and epileptic encephalopathy to identify treatable causes.

"Progressive myoclonic ataxia and developmental/epileptic encephalopathy associated with a novel homozygous mutation in TCN2 gene"

BACKGROUND

Transcobalamin II (TCN2) defect is a rare metabolic disorder associated with a range of neurological manifestations, including mild developmental delay, severe intellectual disability, ataxia, and, in some cases, seizures. Cobalamin, an essential nutrient, plays a crucial role in central nervous system myelination.

CLINICAL PRESENTATION

We present a family with an index patient who exhibited progressive neurodevelopmental regression starting at 9 months of age, accompanied by myoclonic seizures, ataxia, and tremor. No significant hematological abnormalities were observed. Exome sequencing analysis identified a novel homozygous mutation, c.3G>A - P(Met1I), affecting the acceptor site of intron 4 of the TCN2 gene (chromosome 22: 31003321, NM_000355.4), leading to likely pathogenic variant potentially affecting translation. Following treatment with hydroxocobalamin, the patient demonstrated partial clinical improvement. He has a sibling with overt hematological abnormalities and subtle neurological abnormalities who is homozygous to the same mutation. Both parents are heterozygous for the same mutation.

CONCLUSIONS

In infants presenting with unexplained non-specific neurological symptoms, irrespective of classical signs of vitamin B12 deficiency, evaluation for TCN2 defect should be considered. Early diagnosis and appropriate management can lead to favorable outcomes.

Biochemical, Nutritional, and Clinical Parameters of Vitamin B12 Deficiency in Infants: A Systematic Review and Analysis of 292 Cases Published between 1962 and 2022

Pooled data from published reports on infants with clinically diagnosed vitamin B12 (B12) deficiency were analyzed with the purpose of describing the presentation, diagnostic approaches, and risk factors for the condition to inform prevention strategies. An electronic (PubMed database) and manual literature search following the PRISMA approach was conducted (preregistration with the Open Science Framework, accessed on 15 February 2023). Data were described and analyzed using correlation analyses, Chi-square tests, ANOVAs, and regression analyses, and 102 publications (292 cases) were analyzed. The mean age at first symptoms (anemia, various neurological symptoms) was four months; the mean time to diagnosis was 2.6 months. Maternal B12 at diagnosis, exclusive breastfeeding, and a maternal diet low in B12 predicted infant B12, methylmalonic acid, and total homocysteine. Infant B12 deficiency is still not easily diagnosed. Methylmalonic acid and total homocysteine are useful diagnostic parameters in addition to B12 levels. Since maternal B12 status predicts infant B12 status, it would probably be advantageous to target women in early pregnancy or even preconceptionally to prevent infant B12 deficiency, rather than to rely on newborn screening that often does not reliably identify high-risk children.

Epileptic Spasms During Recovery From Nutritional Infantile Vitamin B12 Deficiency

Development of epileptic spasms in infants with vitamin B12 deficiency is uncommon. In some cases, infants presenting with epileptic spasms have been found to have concurrent vitamin B12 deficiency. Treatment with vitamin B12 and adrenocorticotropic hormone (ACTH) resulted in resolution of epileptic spasms. In others, epileptic spasms have developed during recovery from vitamin B12 deficiency. Treatment with ACTH or other seizure medications resulted in resolution of epileptic spasms, although response has been less predictable. We describe three infants who initially presented with clinical and laboratory features of vitamin B12 deficiency. Treatment with vitamin B12 resulted in rapid resolution of symptoms. However, recovery was interrupted by the development of epileptic spasms. All infants showed hypsarrhythmia on electroencephalography. Treatment with prednisolone, with or without other antiseizure medications, resulted in slow resolution of spasms. Cognitive and language delays were noted in two infants. Epileptic spasms may supervene during recovery from vitamin B12 deficiency affecting outcomes.

Nutritional vitamin B12 deficiency-associated Infantile epileptic spasms syndrome: Clinico-neurophysiological presentation, response to treatment, and neurodevelopmental outcome

INTRODUCTION

Nutritional vitamin B12 deficiency has been shown to cause Infantile epileptic spasms syndrome (IESS) in infants in anecdotal studies.

METHODS

In this retrospective cohort study, we intended to study the clinical presentation, neurophysiological, laboratory abnormalities, treatment, and neurodevelopmental outcome at 6-months in infants presenting with IESS secondary to nutritional vitamin B12 deficiency (NVBD) and to compare these variables from the rest of the infants with IESS without vitamin B12 deficiency. We included only spasm-free cases or those who showed at least a 50% reduction in spasm frequency on D7 after starting oral/parenteral vitamin B12. We used well-validated measurement tools like the Developmental Assessment Scale for Indian Infants (DASII), Child Feeding Index (CFI), Burden of amplitudes and epileptiform discharges (BASED) score, countable Hypsarrhythmia paroxysm index (cHPI), durational Hypsarrhythmia paroxysm index (dHPI), and Early childhood epilepsy severity scale (E-CHESS) score for documenting these variables.

RESULTS

Data from 162 infants with IESS (21 caused by NVBD) were included in our study. The NVBD group had more patients residing in the rural region, with lower socioeconomic status, vegetarian mothers and poor complementary feeding index (p<0.001 for all). The NVBD group also had less number of patients requiring antiseizure medications (ASMs) and hormonal therapy(p<0.001), remained seizure free at six months (p=0.008), lower number of clusters per day (p=0.02) and the number of spasms per clusters at presentation (p=0.03), lower BASED score (p=0.03) and cHPI, dHPI at presentation (p<0.001). All of them remained spasm-free, with normal electroencephalogram at 6-months. Development quotient at baseline, at 6-months, and improvement in development quotient between these two-time points were more in the vitamin B12 deficiency group (p<0.001). All of them had clinical features of pre-ITS (infantile tremor syndrome) or ITS and it was found to be the only independent predictor of NVBD in infants with IESS. Mothers of all these infants had low serum vitamin B12 levels (<200 pg/ml).

CONCLUSIONS

Nutritional vitamin B12 deficiency may cause IESS in infants. Hence, vitamin B12 deficiency needs to be ruled out in patients with IESS without any definite etiology.

Serum B12, homocysteine, and anti-parietal cell antibody levels in children with autism

AIMS

To compare vitamin B12, homocysteine, and anti-parietal cell antibody (APCA) levels between children with ASD and controls, paired in terms of age, sex, and socioeconomic level.

METHODS

The research group consisted of 69 children, 36 with ASD and 33 controls. The severity of ASD was determined using the Childhood Autism Rating Scale (CARS). Serum vitamin B12, homocysteine and human anti-parietal cell levels were analysed using enzyme-linked immunosorbent assay.

RESULTS

The serum vitamin B12 and homocysteine levels in children with ASD were lower than in the control group, but there was no significant difference in terms of APCA levels.

CONCLUSIONS

Deficiencies in micronutrients, such as B12, may play a role in the pathogenesis and clinical symptoms of autism. However, it is believed that these parameters should be analysed in a wider population to clarify their effect on the aetiology of ASD.KEY POINTWe hypothesised that low levels of vitamin B12 and homocysteine levels reported in previous studies might be associated with APCA levels.The homocysteine and B12 levels were found to be significantly lower in children with ASD. There was no significant difference in serum APCA levels.No significant relationship was found between B12 levels and APCA.Given all these findings, it can be stated that vitamin B12 deficiency is not associated with an absorption-related mechanism due to the presence of APCA.Deficiencies in micronutrients, such as B12, may play a role in the pathogenesis and clinical symptoms of autism.In future studies, it will be beneficial to investigate other mechanisms that may cause vitamin B12 deficiency.

Clinical and Brain Imaging Findings in a Child with Vitamin B12 Deficiency

Vitamin B12 (Vit-B12) deficiency is a rare and treatable cause of failure to thrive and delayed development in infants who are exclusively breastfed. Apart from genetic causes, it can be related to a malabsorption syndrome or when the mother follows a strict vegetarian or vegan diet, causing a low hepatic storage of Vit-B12 in the infant at birth. As the neurological symptoms are nonspecific, a brain magnetic resonance imaging (MRI) exam is usually performed to rule out primary causes of neurodevelopmental delay. Findings related to brain atrophy are usually observed. A favorable response is achieved with Vit-B12 therapy, and neurological symptoms dramatically improve within a few days after the treatment. We present the case of an infant with severe Vit-B12 deficiency, exclusively breastfed by his young vegan mother, and whose clinical symptoms together with MRI findings improved after treatment. Brain atrophy recovery after Vit-B12 therapy has been seldom documented.

Vitamin B12 Deficiency and West Syndrome: An Uncommon but Preventable Cause of Neurological Disorder. Report on Three Cases, One of Them with Late Onset during Vitamin B12 Treatment

Vitamin B12 is a water-soluble vitamin that plays a fundamental role as an essential cofactor for two enzymes responsible for the production of succinyl-CoA and methionine. Vitamin B12 deficiency can occur in infants and may be related to the breastfeeding mother's adherence to a vegan diet or somatic diseases in the mother. It should be differentiated from inborn errors of vitamin B12 metabolism. Herein, we report the cases of three infants with West syndrome; all three were breastfed by mothers who followed a strict vegan diet. In one of the three infants, West syndrome developed during treatment with vitamin B12 and normalization of the vitamin B12 level. Early treatment and replacement therapy are worthwhile to prevent serious neurological problems and to improve the patient's clinical course.