MEFV gene polymorphisms and TNFRSF1A mutation in patients with inflammatory myopathy with abundant macrophages

Inflammatory myopathy with abundant macrophages (IMAM) has recently been proposed as a new clinical condition. Although IMAM shares certain similarities with other inflammatory myopathies, the mechanisms responsible for this condition remain unknown. Patients with familial Mediterranean fever (FMF) and tumour necrosis factor receptor-associated periodic syndrome (TRAPS) also often develop myalgia. We therefore investigated the polymorphisms or mutations of MEFV and TNFRSF1A genes in patients with IMAM to identify their potential role in this condition. We analysed the clinical features of nine patients with IMAM and sequenced exons of the MEFV and TNFRSF1A genes. The patients with IMAM had clinical symptoms such as myalgia, muscle weakness, erythema, fever and arthralgia. Although none of the patients were diagnosed with FMF or TRAPS, seven demonstrated MEFV polymorphisms (G304R, R202R, E148Q, E148Q-L110P and P369S-R408Q), and one demonstrated a TNFRSF1A mutation (C43R). These results suggest that MEFV gene polymorphisms and TNFRSF1A mutation are susceptibility and modifier genes in IMAM.     

Autosomal dominant familial periodic fever patient with a missense variant c.215G>A (p.Cys72Tyr) in TNFRSF1A gene presenting as neutrophilia

Familial periodic fever (FPF) is an uncommonly diagnosed autosomal dominant disorder caused by a genetic alteration in the TNFRSF1A gene. These patients usually present with fever which is usually under-investigated and under-diagnosed. In untreated cases, amyloidosis is a frequent complication. We present a 24 years male who had a history of fever from childhood, however, remained undiagnosed short of genetic testing. He has recurrent episodes of fever. During the episodes of fever, he was found to have leukocytosis (total leukocyte count- 25.7 x10^9/L) and neutrophilia (absolute neutrophil count- 22.7 x10^9/L) both of which came back to normal limits as the fever subsided. On further evaluation for neutrophilia, the exclusion of common causes of neutrophilia was done. Next-generation sequencing detected a missense variant in TNFRSF1A: c.215G > A (p.Cys72Tyr) which was confirmed by Sanger sequencing. This variant has been described in the literature in anecdotal cases of FPF. This is a first case report from the Indian subcontinent reporting TNFRSF1A: c.215G > A (p.Cys72Tyr) variant in a patient of FPF. Short of genetic testing, the fever would remain a diagnostic dilemma in this patient. This report highlights the importance of targeted resequencing in clinching diagnosis in such patients.     

Clinical and Genetic Characterization of Japanese Sporadic Cases of Periodic Fever,Aphthous Stomatitis,Pharyngitis and Adenitis Syndrome from a Single Medical Center in Japan

Purpose

To investigate clinical presentation, genetic background and cytokine profile of Japanese sporadic cases of periodic fever, aphthous stomatitis, pharyngitis and adenitis (PFAPA) syndrome.

Methods

Nine PFAPA syndrome patients were recruited. DNA sequence analysis of auto inflammatory disorder susceptibility genes, MEFV, MVK, NLRP3, and TNFRSF1A, were performed. Serum cytokine levels and monocyte IL-1β levels were measured by ELISA.

Results

The study population consisted of six males and three females (mean age of onset 26.8 months). Febrile episodes lasted 3–6 days with symptom-free intervals ranging from 2 to 12 weeks. Fever was accompanied by pharyngitis (n?=?8), aphthous stomatitis (n?=?4), and cervical adenitis (n?=?5). White blood cells and C-reactive protein were increased during the attack phase. Mean IgD serum levels were 7.32?±?9.51 mg/dl during the attack phase, and were mildly elevated in two patients. Heterozygous MEFV, NLRP3 and TNFRSF1A variants were detected in four, one and three cases, respectively. Serum TNF-α and IL-18 levels were elevated during the attack-free and attack periods compared with controls. Other cytokines, IL-1β, IL-1ra, IL-6, and sTNFR1, were only increased during the attack phase. Oral prednisolone was administered to eight patients and immediately reduced fever. Tonsillectomy performed in five patients induced cessation of fever in four patients. One case with repeated fever attacks after tonsillectomy showed increased monocyte IL-1β production, similar to the other active case with genetic variants of auto inflammatory disorder-associated genes.

Conclusions

Japanese PFAPA syndrome patients may have cytokine regulation dysfunction as a result of genetic variants of auto inflammatory disorder-associated genes.     

Phenotypic variability in two patients with tumor necrosis factor receptor associated periodic fever syndrome emphasizes a rare manifestation: Immunoglobulin A nephropathy

Tumor necrosis factor receptor associated periodic fever syndrome (TRAPS) is caused by heterozygote mutations in TNFRSF1A, characterized by recurrent inflammatory attacks.In this report, we described two patients with different heterozygote mutations in TNFRSF1A. Patient 1, a 15-year-old male, had suffered from recurrent fever attacks accompanied by abdominal pain, eye manifestations, and myalgia with increased acute phase reactants since the age of 6-month. He had been unsuccessfully treated with colchicine for having familial Mediterranean fever without an identifiable MEFV mutation since the age of 4-year. At the age of 15 years, he was diagnosed with immunoglobulin (Ig) A nephropathy due to massive proteinuria and renal biopsy findings. Next generation sequencing revealed NM_001065.3: c.236C>T; p. (Thr79Met); T50M heterozygote mutation in TNFRFS1A. He was treated with methylprednisolone and cyclosporine for IgA nephropathy, thereafter with canakinumab for TRAPS. Patient 2, a 17-year-old female, had recurrent arthritis attacks accompanied by increased acute phase reactants for the last two months. She had neither fever attacks nor rashes or myalgia. Her physical examination was normal between attacks. Magnetic resonance imaging of both knees and ankles showed no signs of chronic arthritis. MEFV analyzes showed no mutation. Next generation sequencing revealed NM_001065.3: c.362G>A; p.(Arg121Gln); R92Q heterozygote mutation in TNFRFS1A. Arthritis attacks were treated successfully with ibuprofen thereafter.In conclusion, we wish to emphasize the diversity of the clinical manifestations between these two patients with distinct sequence variants in TNFRSF1A. Moreover, we presented a rare manifestation of TRAPS, IgA nephropathy.     

Mediterranean fever gene variants modify clinical phenotypes of idiopathic multi‐centric Castleman disease

Four cases of idiopathic multi‐centric Castleman disease (iMCD) reportedly have variants in hereditary autoinflammatory disease‐related genes; however, the frequency and role of these variants in iMCD is still unknown. We therefore investigated such gene variants among patients with iMCD and aimed to reveal the relationship between iMCD and autoinflammatory disease‐related genes. We reviewed 14 Japanese iMCD patients who were recruited between January 2015 and September 2019. All patients met both the Japanese tentative diagnostic criteria for Castleman disease and the international consensus diagnostic criteria for iMCD. We performed genetic analyses for 31 autoinflammatory disease‐related genes by targeted next‐generation sequencing. The MEFV gene variants were observed in 10 of 14 patients with iMCD. Although iMCD had a high percentage of exons 2 or 3 variants of MEFV, comparison of data from healthy Japanese subjects indicated that there was no significant difference in the percentage between healthy Japanese subjects and patients with iMCD. Variants of uncertain significance (VUS) in the TNFRSF1A and CECR1 genes were observed in two of the patients, respectively. We divided patients into two groups—those with MEFV variants (excluding E148Q variants) and those without MEFV variants—and compared the clinical characteristics between these two groups. Patients with MEFV variants, excluding E148Q variants, exhibited a significantly higher likelihood of fever and significantly lower levels of hemoglobin than those lacking MEFV variants. Our results indicated that patients with iMCD tended to have a high frequency of MEFV gene variants and the presence of such variants can affect iMCD clinical phenotypes.     

In Vitro Analysis of the Functional Effects of an NLRP3 G809S Variant with the co-Existence of MEFV Haplotype Variants in Atypical Autoinflammatory Syndrome

Purpose

Hereditary periodic fever syndromes have been considered monogenic diseases. However, some recent reports have described patients with co-existence of recurrent fever responsible genes. This study assessed whether a rare variant, found in Japanese children showing atypical autoinflammatory syndrome, located in the leucine-rich repeat domain of Nod-like receptor family, pyrin domain containing 3 (NLRP3) with co-existence of Mediterranean fever (MEFV) haplotype variants may contribute to a proinflammatory phenotype using a systematic approach.

Methods

Cytokine production in serum or from peripheral blood monocytes was measured by ELISA. DNA sequence analysis of genes including NLRP3, MEFV, mevalonate kinase (MVK), and tumor necrosis factor receptor superfamily, member 1A (TNFRSF1A) were performed on patient samples. In vitro functional assays determined the effects of the NLRP3 variants and pyrin using NF-κB activation and speck formation assays.

Results

A heterozygous genetic variant of NLRP3, G809S, was found in samples from both patients. Additionally the previously reported heterozygous MEFV variants (P369S-R408Q or E148Q-P369S-R408Q) were also detected in both patients. Serum IL-1ra and sTNFR1 levels increased in the attack phase of the disease in both patients. The production levels of IL-1β from monocytes isolated from both cases were elevated following LPS and IFN-γ stimulation. The NLRP3 G809S variant demonstrated no increase of NF-κB activity following monosodium urate stimulation, whereas it significantly increased speck formation by interacting with apoptosis-associated speck-like protein with caspase recruitment domain.

Conclusions

The phenotype of atypical autoinflammatory disease in patients could be modified by a synergistic effect with two other variants of autoinflammatory-associated genes.     

Role of TNFRSF1B polymorphisms in the response of Crohn’s disease patients to infliximab

Infliximab (IFX) is a valid treatment for Crohn’s disease (CD), but a relevant percentage of patients do not benefit from this therapy. In the Japanese population, the response to IFX was associated with markers in the TNF receptor superfamily 1A (TNFRSF1A) and 1B (TNFRSF1B) genes. We aimed to replicate the association previously described in the Japanese population and to ascertain the role of TNF receptors as modulators of the response to IFX. We studied 297 white Spanish CD patients with a known response to IFX: 238 responders and 59 primary nonresponders. Four single nucleotide polymorphisms (SNPs) were analyzed: rs767455 in TNFRSF1A and rs1061622, rs1061624, and rs3397 in TNFRSF1B. Comparisons between groups were performed with chi-square tests or the Fisher’s exact test. Different features (sex, age, disease duration, smoking among others) were evaluated as possible confounding factors. No significant association was found between the studied TNFRSF1A polymorphisms and response to IFX. In the TNFRSF1B gene, the haplotype rs1061624_A-rs3397_T was significantly increased in nonresponders: p = 0.015, OR = 1.78, 95% CI 1.09–2.90; and an increased frequency of rs1061622_G carriers was observed in patients with remission: p = 0.033 vs nonresponders and p = 0.023 vs patients with a partial response. Our results support a role of TNFRSF1B gene variants in the response to IFX in CD patients.     

Tumor necrosis factor receptor-associated periodic syndrome as a model linking autophagy and inflammation in protein aggregation diseases

Autophagy prevents cellular damage by eliminating insoluble aggregates of mutant misfolded proteins, which accumulate under different pathological conditions. Downregulation of autophagy enhances the inflammatory response and thus represents a possible common pathogenic event underlying a number of autoinflammatory syndromes, such as tumor necrosis factor (TNF) receptor-associated periodic syndrome (TRAPS). The pathogenesis of other monogenic or complex disorders that display symptoms of excessive inflammation also involve the autophagy pathway. Studies have shown that TRAPS-associated TNFRSF1A mutations induce cytoplasmic retention of the TNFR1 receptor, defective TNF-induced apoptosis, and production of reactive oxygen species (ROS). Furthermore, autophagy impairment may account for the pathogenic effects of TNFRSF1A mutations, thus inducing inflammation in TRAPS. In this review, we summarize the molecular interactions and functional links between autophagy with regard to nuclear factor-kappa B activation, ROS production, and apoptosis. Furthermore, we propose a complex interplay of these pathways as a model to explain the relationship between mutant protein misfolding and inflammation in genetically determined and aggregation-prone diseases. Accordingly, autophagy function should be investigated in all diseases showing an inflammatory component, and for which the molecular pathogenesis is still unclear.     

Allelic variants in genes associated with hereditary periodic fever syndromes as susceptibility factors for reactive systemic AA amyloidosis

We investigated the hypothesis that low-penetrance mutations in genes (TNFRSF1A, MEFV and NALP3/CIAS1) associated with hereditary periodic fever syndromes (HPFs) might be risk factors for AA amyloidosis among patients with chronic inflammatory disorders, including rheumatoid arthritis (RA), juvenile idiopathic arthritis (JIA), Crohn's disease, undiagnosed recurrent fevers and HPFs themselves. Four of 67 patients with RA plus amyloidosis had MEFV variants compared with none of 34 RA patients without amyloid (P value=0.03). The E148Q variant of MEFV was present in two of the three patients with TNF receptor-associated periodic syndrome (TRAPS) complicated by amyloid in two separate multiplex TRAPS families containing 5 and 16 affected members respectively, and the single patient with Muckle-Wells syndrome who had amyloidosis was homozygous for this variant. The R92Q variant of TNFRSF1A was present in two of 61 JIA patients with amyloidosis, and none of 31 nonamyloidotic JIA patients. No HPF gene mutations were found in 130 healthy control subjects. Although allelic variants in HPFs genes are not major susceptibility factors for AA amyloidosis in chronic inflammatory disease, low-penetrance variants of MEFV and TNFRSF1A may have clinically significant proinflammatory effects.     

Molecular genetic evaluation of NLRP3, MVK and TNFRSF1A associated periodic fever syndromes

Periodic fever syndromes (PFSs) are a family of clinical disorders, which are characterized by recurrent episodes of fever in the absence of microbial, autoimmune or malign conditions. Most common types of PFSs are associated with four genes: MEFV, MVK, TNFRSF1A and NLRP3. This paper aims to add new data to the genotype–phenotype association of MVK-, TNFRSF-1A- and NLRP3‐associated PFSs. A total number of 211 patients were evaluated. Two different approaches were used for the molecular genetic evaluation of MVK-, TNFRSF-1A- and NLRP3‐associated PFSs. For the first 147 patients, Sanger sequence analysis of selected exons of MVK, TNFRSF1A and NLRP3 genes was done. For subsequent 64 patients, targeted NGS panel analysis, covering all exons of MVK, TNFRSF1A and NLRP3 genes, was used. A total number of 48 variants were detected. The “variant detection rate in index patients” was higher in the NGS group than Sanger sequencing group (19% vs. 15,1%). For the variant positive patients, a detailed genotype–phenotype table was built. In PFSs, lack of correlation exists between genotype and phenotype in the general population and even within the families. In some cases, mutations behave differently and yield unexpected phenotypes. In this study, we discussed the clinical effects of eight different variants we have detected in the MVK, TNFRSF1A and NLRP3 genes. Four of them were previously identified in patients with PFS. The remaining four were not reported in patients with PFS. Thus, we had to interpret their clinical effects by analysing their frequencies and in silico analysis predictions. We suggest that new studies are needed to evaluate the effects of these variants more clearly. To be able to demonstrate a clearer genotype–phenotype relationship, all PFS‐related genes should be analysed together and the possibility of polygenic inheritance should be considered.     

TNF receptor-associated periodic syndrome (TRAPS) in Japan: clinical characterization, pathogenesis, diagnostic criteria, and treatment]

TNF receptor-associated periodic syndrome (TRAPS) is an autosomal dominant inherited disease characterized by prolonged episodes of periodic fever and localized inflammation. The hypothetical pathogenesis of TRAPS is defective TNF receptor 1 (TNFRSF1A) shedding from cell membranes in response to a stimulus including TNFalpha. This mechanism has recently been shown to account for a minor population of TRAPS patients and other mechanisms are reported to explain the disease, such as resistance to apoptosis, TNFRSF1A internalization, or TNFRSF1A misfolding and aggregation, leading to NF-kappaB activation and apoptosis. Until now 15 TRAPS patients from 5 pedigree including 5 different mutations (C30R, C30Y, T61I, C70S, C70G) had been reported in Japan. There were many sporadic cases of TRAPS without TNFRSF1A mutation in our epidemiological study. In this issue, we described the clinical characterization, pathogenesis, diagnostic criteria, and treatment of TRAPS according to our case and literature.     

Tumour necrosis factor receptor-associated periodic syndrome (TRAPS): State of the art and future perspectives

Tumor necrosis factor (TNF) receptor-associated periodic syndrome (TRAPS) is an autosomal dominant autoinflammatory disorder characterized by periodic fever episodes, arthralgia, myalgia, abdominal pain, serositis, and skin rash. TRAPS is caused by mutations in the gene encoding the TNF Receptor Super Family 1A (TNFRSF1A) on chromosome 12p13. The identification of TNFRSF1A mutations as the genetic cause of TRAPS coincided with the wider use of biological agents in medicine and raised the possibility that blocking TNF could potentially represent the primary therapeutic goal in TRAPS, thus disclosing new treatment choices for this complex disease. Anti-TNF therapy in TRAPS has been based on etanercept, a recombinant human TNFR (p75)-Fc fusion protein comprising two receptors linked by an IgG₁ Fc fragment. However a decrease in responsiveness to etanercept over time has been described, and it may be due to a non-specific action of etanercept in TRAPS; its efficacy may reflect ‘generic’ anti-inflammatory properties. Long-term adherence to etanercept is poor and a significant number of patients need to switch to anti-interleukin (IL)-1β therapy. In fact, the IL-1 receptor antagonist anakinra has recently been shown to prevent disease relapses both in the short- and in the long-term, and to induce a prompt and stable disease remission.     

Clinical and Genetic Profile of Children with Periodic Fever Syndromes from a Single Medical Center in South East Michigan

Objective

To report a cohort of children with periodic fever syndromes (PFS) from Southeast Michigan.

Methods

A retrospective review of medical records for patients referred for periodic fever over 5 years.

Results

Sixty-six patients including 21 FMF, 15 PFAPA, four TRAPS and one patient with combined HIDS and FMF were included. In addition, 25 patients were categorized as clinical PFS (cPFS) based on their clinical features however their genetic workup was either negative or inconclusive. Majority of the patients with FMF were from Middle Eastern background (88 %), but positive family history was noted in only 55 % of cases. Mean age at diagnosis was 40.8 months with a mean delay in diagnosis of 24 months. Most common MEFV mutations were p.M694V and p.M694I. Four patients with TRAPS were from mixed European descent and age at onset of symptoms was 6, 12, 12, and 84 months respectively. TNFRSF1A sequence variants in the TRAPS patients included p.R121Q (R92Q) and p.C99G (C70G); one patient had a rare occurrence of a concurrent p.V726A/-MEFV mutation. One patient with HIDS and FMF presented with atypical overlapping PFS clinical manifestations and genetic evaluation showed a unique combination of p.I268T/p.V377I MVK mutations and p.E230K/-MEFV variant. All patients with PFAPA group were from mixed European descent, symptoms started at a mean age of 34.6 months with a mean delay in diagnosis of 23.3 months. Symptoms started during infancy in six patients. All patients fulfilled the diagnostic criteria for PFAPA. The mean age of onset of symptoms in cPFS group was 17.2 months. Empiric colchicine and glucocorticosteroids controlled flares in majority of patients with cPFS. No evidence of amyloidosis was found in this entire cohort of 66 patients after a mean of 29.2 months of follow-up.

Conclusion

PFS can present with atypical manifestations and should not be excluded based on a negative family history. Concomitant mutations in different autoinflammatory disorders genes can be present and possibly explain atypical manifestations. Various therapies may be considered even if genetic testing is inconclusive or negative.     

A novel Y331X nonsense mutation in TNFRSF1A gene in two unrelated Turkish families with periodic fever syndrome

The autoinflammatory disorders differ in severity, as well as age of onset, duration, and manifestations, but they all share some common features: recurring fever peaks, inflammation of serosal membranes, musculoskeletal involvement, varying types of skin rash, amyloidosis as a sequel of the disease. TRAPS is very rare in Turkish population and we present two unrelated Turkish children with similar clinical phenotypes and laboratory findings related with autoinflammatory disorders and with novel p. Y331X mutation in TNFRSF1A gene. Both of the patients were male and they had recurrent fever without abdominal pain and arthralgia. Full cDNA and exon–intron binding regions of TNFRSF1A, MEFV, MVK, CIAS1 genes were analysed by direct DNA sequencing methods in order to differentiate TRAPS, FMF, HIDS, CINCA/MWS/FCAS respectively. We screened ten exons of TNFRSF1A gene, and detected a heterozygous c.1080C>G nucleotide substitution in exon 10 in both of the unrelated patients, resulting p.Y360X nonsense (protein truncated) mutation. According to classical TNFRSF1A gene nomenclature and the agreement of 30th amino acid as the first one, it is accepted as p.Y331X. It was interesting to determine same mutations in fathers of two patients. In one of the cases, E148Q heterozygous mutation, which is one of the disease-causing mutations of MEFV gene, was detected. No nucleotide substitution was identified in exon and exon–intron splicing regions encoding 396 amino acid of MVK gene in both of the patients. In CIAS1 gene, two different nucleotide substitutions resulting synonymous amino acid mutation were detected in exon 3: c.[732G>A] and c.[786A>G] nucleotide substitutions and compatible p.A242A (according to c.DNA p.A244A) and p.R260R (according to c.DNA p.R262R) synonymous amino acid mutations. These nucleotide substitutions were also detected in parents and were reported to be normal variations in Turkish population. In conclusion, in Turkish patients, with dominantly inherited recurrent fever, TRAPS is a diagnosis worthy of attention and novel mutations have to be reported with phenotype associations.     

SCN4A variants and Brugada syndrome: phenotypic and genotypic overlap between cardiac and skeletal muscle sodium channelopathies

SCN5A mutations involving the α-subunit of the cardiac voltage-gated muscle sodium channel (NaV1.5) result in different cardiac channelopathies with an autosomal-dominant inheritance such as Brugada syndrome. On the other hand, mutations in SCN4A encoding the α-subunit of the skeletal voltage-gated sodium channel (NaV1.4) cause non-dystrophic myotonia and/or periodic paralysis. In this study, we investigated whether cardiac arrhythmias or channelopathies such as Brugada syndrome can be part of the clinical phenotype associated with SCN4A variants and whether patients with Brugada syndrome present with non-dystrophic myotonia or periodic paralysis and related gene mutations. We therefore screened seven families with different SCN4A variants and non-dystrophic myotonia phenotypes for Brugada syndrome and performed a neurological, neurophysiological and genetic work-up in 107 Brugada families. In the families with an SCN4A-associated non-dystrophic myotonia, three patients had a clinical diagnosis of Brugada syndrome, whereas we found a remarkably high prevalence of myotonic features involving different genes in the families with Brugada syndrome. One Brugada family carried an SCN4A variant that is predicted to probably affect function, one family suffered from a not genetically confirmed non-dystrophic myotonia, one family was diagnosed with myotonic dystrophy (DMPK gene) and one family had a Thomsen disease myotonia congenita (CLCN1 variant that affects function). Our findings and data suggest a possible involvement of SCN4A variants in the pathophysiological mechanism underlying the development of a spontaneous or drug-induced type 1 electrocardiographic pattern and the occurrence of malignant arrhythmias in some patients with Brugada syndrome.     

Sequence variants of the TNFRSF13B gene in Czech CVID and IgAD patients in the context of other populations

Mutations in the TNFRSF13B gene, encoding TACI, have been found in common variable immunodeficiency (CVID) and selective IgA deficient (IgAD) patients, but only the association with CVID seems to be significant. In this study, Czech CVID, IgAD and primary hypo/dysgammaglobulinemic (HG/DG) patients were screened for all TNFRSF13B sequence variants. The TNFRSF13B gene was mutated in 4/70 CVID patients (5.7%), 9/161 IgAD patients (5.6%), 1/17 HG/DG patient (5.9%) and none of 195 controls. Eight different mutations were detected, including the most frequent p.C104R and p.A181E mutations as well as 1 novel missense mutation, p.R189K. A significant association of TNFRSF13B gene mutations was observed in both CVID (p = 0.01) and IgAD (p = 0.002) Czech patients. However, when combined with all published data, only the association with CVID remained significant compared with the controls (9.9% vs. 3.2%, p < 10⁻⁶), while statistical significance disappeared for IgAD (5.7% vs. 3.2%, p = 0.145). The silent mutation p.P97P was shown to be associated significantly with CVID compared with the controls in both Czech patients (allele frequency 4.3% vs. 0.2%, p = 0.01) and in connection with the published data (5.1% vs. 1.8%, p = 0.003). The relevance of some TNFRSF13B gene variants remains unclear and needs to be elucidated in future studies.     

Association of FCGR2A p.R131H and CCL2 c.-2518 A > G gene variants with thrombocytopenia in patients with dengue virus infection

FCGR2A and CCL2 gene variants are important in dengue pathogenesis and were investigated in 122 dengue patients (DENs) [89 dengue fever (DF) and 33 dengue hemorrhagic fever (DHF)] and 107 healthy controls (HCs) to find out their association with severity of dengue. Genotype frequencies of FCGR2A p.R131H and CCL2 c.-2518 A > G polymorphisms were not different between DF, DHF and HC. Significantly higher frequency of R/R genotype of FCGR2A p.R131H was observed in DEN cases with thrombocytopenia (TP) while the G/G genotype of CCL2 c.-2518 A > G was observed only in DEN cases with TP (p < 0.005). These results suggest that FCGR2A and CCL2 gene variants were associated with the risk of TP in dengue infections.     

MFSD2A-associated primary microcephaly - Expanding the clinical and mutational spectrum of this ultra-rare disease

MFSD2A, a member of the major facilitator superfamily (MFS), is a transmembrane transporter responsible for the uptake of specific essential fatty acids through the blood-brain barrier (BBB) to the brain. The transporter is crucial for early embryonic brain development and a major factor in the formation and maintenance of the BBB. Mfsd2a-knockout mice show a leakage of the BBB in early embryonic stages and develop a phenotype characterized by microcephaly, cognitive impairment, and anxiety. So far, homozygous or compound heterozygous MFSD2A mutations in humans have only been reported in 13 different families with a total of 28 affected individuals. The phenotypical spectrum of patients with MFSD2A variants is rather broad but all patients present with microcephaly and severe intellectual disability, absent or limited speech, and walking difficulties. Severely affected patients develop seizures and show brain malformations and have, above all, a profound developmental delay hardly reaching any developmental motor milestones. Here, we report on two unrelated individuals with novel homozygous variants in the MFSD2A gene, presenting with severe primary microcephaly, brain malformations, profound developmental delay, and epilepsy, including hypsarrhythmia.Our findings extend the mutational spectrum of the bi-allelic MFSD2A variants causing autosomal recessive primary microcephaly type 15 and broaden the phenotypic spectrum associated with these pathogenic variants emphasizing the role of MFSD2A in early brain development.