Clinical, biochemical and genotypical characteristics in biotinidase deficiency

Proteomic map of the differentially expressed proteins in the skin of Ctenopharyngodon idella against Aeromonas hydrophila infection

The skin mucus of fish is an important part of the innate immune system, which is poorly understood at the proteomic level. The study established a complete map of the proteins in the skin mucus of Ctenopharangdon idella (C. idella) and discussed the Differentially Expressed Proteins (DEPs) after Aeromonas hydrophila (A. hydrophila) infection. Using Label Free Liquid Chromatography-Mass Spectrometry (LC-MS/MS) analysis, a total of 126 proteins were identified as differentially expressed, 89 proteins of which were upregulated, and 37 proteins were downregulated. Functional annotations of DEPs showed that the upregulated proteins in the skin mucus of the treated group were mostly associated with complement system and cytoskeleton proteins, whereas downregulated proteins were associated with metabolism. The key upregulated immune proteins were transferrin variant C, lysozyme g, annexin A11, 26S proteasome non-ATPase regulatory subunit 8, hypothetical protein ROHU_000884, 60S ribosomal L7a, calpain-2 catalytic subunit-like protein, calpain-9-like protein, complement component C9, complement C3, cathepsin S, cathepsin Z, 14 kDa apolipo, heat shock protein and intelectin, whereas, leukocyte elastase inhibitor, annexin A11, C-factor-like protein, biotinidase isoform X1 and epidermal growth factor receptor substrate 15-like were the downregulated proteins. Moreover, we for the first-time report proteins such as coactosin, lamin-B2 and kelch 12, which were never reported in fish. Our study directly pointing out the possible immunological biomarkers in the skin mucus of C. idella after A. hydrophila treatment. Each of the protein we report in this study could be used as base to establish their mechanism of action during bacterial infection that may contribute to the strategies against bacterial prevention and control in fishes.

Exome analysis focusing on epilepsy-related genes in children and adults with sudden unexplained death

PURPOSE

Genetic studies in sudden infant death syndrome (SIDS) and sudden unexplained death (SUD) cohorts have indicated that cardiovascular diseases might have contributed to sudden unexpected death in 20-35 % of autopsy-negative cases. Sudden unexpected death can also occur in people with epilepsy, termed as sudden unexpected death in epilepsy (SUDEP). The pathophysiological mechanisms of SUDEP are not well understood, but are likely multifactorial, including seizure-induced hypoventilation and arrhythmias as well as genetic risk factors. The sudden death of some of the SIDS/SUD victims might also be explained by genetic epilepsy, therefore this study aimed to expand the post-mortem genetic analysis of SIDS/SUD cases to epilepsy-related genes.

METHODS

Existing whole-exome sequencing data from our 155 SIDS and 45 SUD cases were analyzed, with a focus on 365 epilepsy-related genes. Nine of the SUD victims had a known medical history of epilepsy, seizures or other underlying neurological conditions and were therefore classified as SUDEP cases.

RESULTS

In our SIDS and SUD cohorts, we found epilepsy-related pathogenic/likely pathogenic variants in the genes OPA1, RAI1, SCN3A, SCN5A and TSC2.

CONCLUSION

Post-mortem analysis of epilepsy-related genes identified potentially disease-causing variants that might have contributed to the sudden death events in our SIDS/SUD cases. However, the interpretation of identified variants remains challenging and often changes over time as more data is gathered. Overall, this study contributes insight in potentially pathophysiological epilepsy-related mechanisms in SIDS, SUD and SUDEP victims and underlines the importance of sensible counselling on the risk and preventive measures in genetic epilepsy.

Improvements in Gut Microbiome Composition Predict the Clinical Efficacy of a Novel Synbiotics Formula in Children with Mild to Moderate Atopic Dermatitis

Atopic dermatitis (AD) is a common chronic inflammatory skin disease with a significant association with various type-2 inflammation-related comorbidities. Ongoing research suggests the crucial involvement of gut microbiome, especially in childhood onset AD, and hence, probiotics have emerged as a potential non-steroid-based therapeutics option to complement existing AD management plans. In order to delineate the impact of probiotics in the gut microbiome of pediatric AD patients from southern China, targeted 16S rRNA sequencing and thorough bioinformatic analysis were performed to analyze the gut microbiome profiles of 24 AD children after taking an orally administered novel synbiotics formula with triple prebiotics for 8 weeks. A notable improvement in Eczema Area and Severity Index (EASI) (p = 0.008) was observed after taking an 8-week course of probiotics, with no adverse effects observed. The relative abundances of key microbial drivers including Bacteroides fragilis and Lactobacillus acidophilus were significantly increased at week 8. We also found that the positive responsiveness towards an 8-week course of probiotics was associated with improvements in the gut microbiome profile with a higher relative abundance of probiotic species. Over-represented functional abundance pathways related to vitamin B synthesis and peptidoglycan recycling may imply the underlying mechanism. In summary, our study suggests how the gut microbial landscape shifts upon probiotic supplementation in AD children, and provides preliminary evidence to support targeted probiotic supplementation for the management of childhood AD.

Evaluation of 700 patients referred with a preliminary diagnosis of biotinidase deficiency by the national newborn metabolic screening program: a single-center experience

OBJECTIVES

This study aimed to investigate the clinical, demographic and laboratory characteristics of the patients referred with a preliminary diagnosis of biotinidase deficiency through the national newborn metabolic screening program. We also attempted to determine the cut-off level of the fluorometric method used for screening biotinidase deficiency by the Ministry of Health.

METHODS

A total of 700 subjects who were referred to the Pediatric Metabolism Outpatient Clinic with a preliminary diagnosis of biotinidase deficiency through the national newborn metabolic screening program were retrospectively evaluated. Patients detected by family screening were excluded. Biotinidase enzyme activity was assessed and BTD gene analysis was performed in all patients.

RESULTS

Of 700 subjects who were referred by the screening program, 284 (40.5 %) had biotinidase deficiency (BD). The enzyme activity was 0-10, 10-30 and >30 % in 39 (5.5 %), 245 (35 %) and 416 (59.5 %) patients, respectively. The BD was partial in majority of patients (86.2 %). The cut-off level was 59.5 MRU for partial BD and 50.5 MRU for profound BD. The most common mutation detected was p.Arg157His (c.470G>A) among patients with profound BD, and p.D444H (c.1330G>C) among patients with partial BD.

CONCLUSIONS

Treatment should be initiated promptly in patients who are referred by the newborn screening program. Any mean activity under 59.5 MRU should be considered partial BD, while less than 50.5 MRU should be considered profound BD. It should be kept in mind that clinical manifestations may develop both in profound and partial BD.

Biotinidase deficiency: What have we learned in forty years?

BACKGROUND

Biotinidase deficiency (BD) is an autosomal recessively inherited disorder that was first described in 1982. Forty years after its first description, we compiled available clinical data on BD with the aim of generating a more comprehensive picture of this condition.

METHODS

A systematic search strategy was performed in relevant databases without limits for publication date or languages. We screened 3966 records and included 144 articles reporting individuals with BD and their clinical presentation as well as the outcomes, when available.

RESULTS

This study included 1113 individuals with BD. More than half (51.5%) of these individuals were diagnosed by newborn screening, 43.3% in presence of clinical symptoms and 5.2% due to family screening. We grouped symptomatic individuals into four main clinical presentations: neonatal-onset (<1 month; 7.9%), early childhood-onset (<2 years; 59.2%), juvenile-onset (2-16 years; 25.1%) and adult-onset (>16 years; 7.7%). BD affected five main organ systems: nervous system (67.2%), skin (53.7%), eye (34.4%), auditory (26.9%) and respiratory system (17.8%). Involvement was mainly multisystemic (82.2%) of individuals, whereas isolated system presentation was seen in only 17.2% of individuals. When reported, metabolic acidosis was present in 42.4% of symptomatic individuals and characteristic abnormal organic acid metabolites were found in 57.1%. Biotin treatment led to clinical stability or improvement in 89.2% of individuals. 1.6% of reported individuals with BD died due to non-availability of treatment or late diagnosis.

CONCLUSION

Newborn screening has had a major positive impact on the outcome of many individuals with BD. However, undiagnosed and non-treated BD remains a health concern. Given the risk of mortality or complications associated with late or missed diagnosis if newborn screening is not available, a trial of biotin should be considered in undiagnosed infants and adults exhibiting suspected clinical signs. Enzymatic activity and/or analysis of genetic variants can readily confirm the diagnosis of BD.