GIMAP5 deficiency reveals a mammalian ceramide-driven longevity assurance pathway.

Preserving cells in a functional, non-senescent state is a major goal for extending human healthspans. Model organisms reveal that longevity and senescence are genetically controlled, but how genes control longevity in different mammalian tissues is unknown. Here, we report a new human genetic disease that causes cell senescence, liver and immune dysfunction, and early mortality that results from deficiency of GIMAP5, an evolutionarily conserved GTPase selectively expressed in lymphocytes and endothelial cells. We show that GIMAP5 restricts the pathological accumulation of long-chain ceramides (CERs), thereby regulating longevity. GIMAP5 controls CER abundance by interacting with protein kinase CK2 (CK2), attenuating its ability to activate CER synthases. Inhibition of CK2 and CER synthase rescues GIMAP5-deficient T cells by preventing CER overaccumulation and cell deterioration. Thus, GIMAP5 controls longevity assurance pathways crucial for immune function and healthspan in mammals.

Very-early-onset Inflammatory Bowel Disease in an Infant with a Partial RIPK1 Deletion.

The monogenic causes of very-early-onset inflammatory bowel disease (VEO-IBD) have been defined by genetic studies, which were usually related to primary immunodeficiencies. Receptor-interacting serine/threonine-protein kinase-1 (RIPK1) protein is an important signalling molecule in inflammation and cell death pathways. Its deficiency may lead to various clinical features linked to immunodeficiency and/or inflammation, including IBD. Here, we discuss an infant with malnutrition, VEO-IBD, recurrent infections and polyathritis who has a homozygous partial deletion in RIPK1 gene.

Evaluation of Gastrointestinal System Complaints and Comorbidities in Pediatric Familial Mediterranean Fever Patients.

OBJECTIVE: Familial Mediterranean fever (FMF) is the most prevalent hereditary autoinflammatory disease among children. Abdominal pain and various gastrointestinal system (GIS) manifestations may arise directly from FMF or concomitantly with FMF. This study aimed to evaluate GIS complaints and findings other than classic peritonitis attacks in patients with FMF and to interpret concomitant GIS and hepatic disorders in these patients. METHODS: The medical and genetic findings of patients with FMF who attended our clinic between December 2011 and December 2021 were reviewed. Gastrointestinal system symptoms, liver function tests, abdominal images, and endoscopic and histopathological data were extracted from medical records. RESULTS: A total of 576 pediatric patients (female, 52.3%) diagnosed with FMF were included. Among them, almost one-fifth displayed GIS complaints, such as abdominal pain, defecation problems, and dyspepsia, distinct from typical FMF attacks. High serum aminotransferase levels were detected in 18.4% of the patients, with viral infections being the most common cause of moderate/severe hypertransaminasemia. In addition, during follow-up, 26.9% of them were referred to the pediatric gastroenterology department. At least 1 gastroenterological and hepatobiliary disorder was detected in 17.5% of the patients because of organic and functional GIS disorders or hepatobiliary disorders, such as gastroesophageal reflux disease, esophagitis, functional dyspepsia, and inflammatory bowel diseases. CONCLUSION: Various GIS and hepatic disorders can be encountered in children with FMF. The spectrum of these complaints and pathologies can range from frequently observed health problems to more severe diseases.

A Novel PUS1 Mutation in 2 Siblings with MLASA Syndrome: A Review of the Literature.

ABSTRACT: Myopathy, lactic acidosis, and sideroblastic anemia (MLASA) is a rare mitochondrial disorder characterized by MLASA. Variable features of this condition include failure to thrive, and developmental delay or intellectual disability. Additional symptoms consist of cognitive impairment, skeletal and dental abnormalities, delayed motor milestones, cardiomyopathy, dysphagia, and respiratory insufficiency. MLASA has previously been associated with mutations in pseudouridylate synthase 1 (PUS1) and YARS2. PUS1 encodes the nuclear PUS1 enzyme, which is located in both the nucleus and the mitochondria. PUS1 converts uridine into pseudouridine in several cytosolic and mitochondrial transfer RNA positions and increases the efficiency of protein synthesis in both compartments.In the present report, we report on 2 Turkish sisters 4 and 11 of years with an MLASA plus phenotype. Both patients have sideroblastic anemia, lactic acidosis, failure to thrive, developmental delay, and chronic diarrhea; in addition, the older sister has strabismus and skeletal anomalies. The sequencing of the PUS1 gene revealed a novel homozygous p.Glu311* mutation. The phenotype of the older sibling is also unique because of the strabismus and skeletal anomalies, when compared with her sister and other previously reported patients with MLASA. The structural differences in the nuclear versus mitochondrial isoforms of PUS1 and modifier genes may be implicated in the variability of the clinical presentations in MLASA. CONCLUSION: This report adds to the growing number of mutations causing complex clinical manifestations of MLASA including lactic acidosis, sideroblastic anemia, chronic diarrhea, and myopathy.

Transaldolase haploinsufficiency in subjects with acetaminophen-induced liver failure.

Transaldolase (TAL) is an enzyme in the pentose phosphate pathway (PPP) that generates NADPH for protection against oxidative stress. While deficiency of other PPP enzymes, such as transketolase (TKT), are incompatible with mammalian cell survival, mice lacking TAL are viable and develop progressive liver disease attributed to oxidative stress. Mice with homozygous or heterozygous TAL deficiency are predisposed to cirrhosis, hepatocellular carcinoma (HCC) and acetaminophen (APAP)-induced liver failure. Both mice and humans with complete TAL deficiency accumulate sedoheptulose 7-phosphate (S7P). Previous human studies relied on screening patients with S7P accumulation, thus excluding potentially pathogenic haploinsufficiency. Of note, mice with TAL haploinsufficiency are also predisposed to HCC and APAP-induced liver failure which are preventable with oral N-acetylcysteine (NAC) administration. Based on TALDO1 DNA sequencing, we detected functional TAL deficiency due to novel, heterozygous variations in two of 94 healthy adults and four of 27 subjects with APAP-induced liver failure (P = .022). The functional consequences of these variations were individually validated by site-directed mutagenesis of normal cDNA and loss of activity by recombinant enzyme. All four patients with TAL haplo-insufficiency with APAP-induced liver failure were successfully treated with NAC. We also document two novel variations in two of 15 children with previously unexplained liver cirrhosis. Examination of the National Center for Biotechnology Information databases revealed 274 coding region variations have been documented in 1125 TALDO1 sequences relative to 25 variations in 2870 TKT sequences (P < .0001). These findings suggest an unexpected prevalence and variety of genetic changes in human TALDO1 with relevance for liver injury that may be preventable by treatment with NAC.

Assessment of cows milk-related symptom scoring awareness tool in young Turkish children.

BACKGROUND: The diagnosis of cows milk protein allergy (CMPA) is not always easy. Cow's Milk-related Symptom Score (CoMiSS) has been developed to raise the awareness of CMPA among the primary health-care providers. In this study, we aimed to evaluate the validity of CoMiSS as a diagnostic approach of CMPA in infants in our country. METHODS: Infants with a CoMiSS of more than 12 points were included. An elimination diet was implemented in these infants for 4 weeks, and CoMiSS was reapplied. Infants with a reduction of ≥3 points in CoMiSS were considered responsive to the elimination diet, and an open oral challenge test was performed. Infants with symptom recurrence were diagnosed with CMPA. RESULTS: The study included 168 infants. When they were included in the study, the first CoMiSS score was 13.6 ± 1.9. After the elimination diet, the number of responsive infants was 154 (91.7%). Of the infants, 91 (54.2%) were diagnosed with CMPA with positive challenge. The majority of the patients diagnosed with CMPA presented with gastrointestinal and/or dermatological symptoms (80.3%). Positive family history of allergy was more prevalent in CMPA(+) infants (P < 0.001). The mean atopic dermatitis score was higher in CMPA(+) infants (P = 0.001). Eosinophilia and cows milk-specific IgE (CM-sIgE) positivity were more prevalent in infants with CMPA (P = 0.01 and P < 0.001, respectively). CONCLUSIONS: CoMiSS is a valuable tool to evaluate CMPA in primary care. The presence of multiple symptoms, especially skin involvement, helps to recognise infants with CMPA. Family history and eosinophilia also support the diagnosis of CMPA.

Intestinal Failure and Aberrant Lipid Metabolism in Patients With DGAT1 Deficiency.

BACKGROUND & AIMS: Congenital diarrheal disorders are rare inherited intestinal disorders characterized by intractable, sometimes life-threatening, diarrhea and nutrient malabsorption; some have been associated with mutations in diacylglycerol-acyltransferase 1 (DGAT1), which catalyzes formation of triacylglycerol from diacylglycerol and acyl-CoA. We investigated the mechanisms by which DGAT1 deficiency contributes to intestinal failure using patient-derived organoids. METHODS: We collected blood samples from 10 patients, from 6 unrelated pedigrees, who presented with early-onset severe diarrhea and/or vomiting, hypoalbuminemia, and/or (fatal) protein-losing enteropathy with intestinal failure; we performed next-generation sequencing analysis of DNA from 8 patients. Organoids were generated from duodenal biopsies from 3 patients and 3 healthy individuals (controls). Caco-2 cells and patient-derived dermal fibroblasts were transfected or transduced with vectors that express full-length or mutant forms of DGAT1 or full-length DGAT2. We performed CRISPR/Cas9-guided disruption of DGAT1 in control intestinal organoids. Cells and organoids were analyzed by immunoblot, immunofluorescence, flow cytometry, chromatography, quantitative real-time polymerase chain reaction, and for the activity of caspases 3 and 7. RESULTS: In the 10 patients, we identified 5 bi-allelic loss-of-function mutations in DGAT1. In patient-derived fibroblasts and organoids, the mutations reduced expression of DGAT1 protein and altered triacylglycerol metabolism, resulting in decreased lipid droplet formation after oleic acid addition. Expression of full-length DGAT2 in patient-derived fibroblasts restored formation of lipid droplets. Organoids derived from patients with DGAT1 mutations were more susceptible to lipid-induced cell death than control organoids. CONCLUSIONS: We identified a large cohort of patients with congenital diarrheal disorders with mutations in DGAT1 that reduced expression of its product; dermal fibroblasts and intestinal organoids derived from these patients had altered lipid metabolism and were susceptible to lipid-induced cell death. Expression of full-length wildtype DGAT1 or DGAT2 restored normal lipid metabolism in these cells. These findings indicate the importance of DGAT1 in fat metabolism and lipotoxicity in the intestinal epithelium. A fat-free diet might serve as the first line of therapy for patients with reduced DGAT1 expression. It is important to identify genetic variants associated with congenital diarrheal disorders for proper diagnosis and selection of treatment strategies.

The Frequency of Lysosomal Acid Lipase Deficiency in Children With Unexplained Liver Disease.

OBJECTIVES: Evidence suggests that lysosomal acid lipase deficiency (LAL-D) is often underdiagnosed because symptoms may be nonspecific. We aimed to investigate the prevalence of LAL-D in children with unexplained liver disease and to identify demographic and clinical features with a prospective, multicenter, cross-sectional study. METHODS: Patients (aged 3 months-18 years) who had unexplained transaminase elevation, unexplained hepatomegaly or hepatosplenomegaly, obesity-unrelated liver steatosis, biopsy-proven cryptogenic fibrosis and cirrhosis, or liver transplantation for cryptogenic cirrhosis were enrolled. A Web-based electronic data collection system was used. LAL activity (nmol/punch/h) was measured using the dried blood spot method and classified as LAL-D (<0.02), intermediate (0.02-0.37) or normal (> 0.37). A second dried blood spot sample was obtained from patients with intermediate LAL activity for confirmation of the result. RESULTS: A total of 810 children (median age 5.6 years) from 795 families were enrolled. The reasons for enrollment were unexplained transaminase elevation (62%), unexplained organomegaly (45%), obesity-unrelated liver steatosis (26%), cryptogenic fibrosis and cirrhosis (6%), and liver transplantation for cryptogenic cirrhosis (<1%). LAL activity was normal in 634 (78%) and intermediate in 174 (21%) patients. LAL-D was identified in 2 siblings aged 15 and 6 years born to unrelated parents. Dyslipidemia, liver steatosis, and mild increase in aminotransferases were common features in these patients. Moreover, the 15-year-old patient showed growth failure and microvesicular steatosis, portal inflammation, and bridging fibrosis in the liver biopsy. Based on 795 families, 2 siblings in the same family were identified as LAL-D cases, making the prevalence of LAL-D in this study population, 0.1% (0.125%-0.606%). In the repeated measurement (76/174), LAL activity remained at the intermediate level in 38 patients. CONCLUSIONS: Overall, the frequency of LAL-D patients in this study (0.1%) suggests that LAL-D seems to be rare even in the selected high-risk population.

Allogeneic hematopoietic stem cell and liver transplantation in a young girl with dedicator of cytokinesis 8 protein deficiency.

DOCK8 deficiency is a rare inherited combined immunodeficiency, caused by mutations in the DOCK8 gene. We describe a case with DOCK8 deficiency associated with severe CLD in whom orthotopic LT was performed successfully after allogeneic HSCT. A 5 year-old girl with DOCK8 deficiency presented with mild direct hyperbilirubinemia and abnormal GGT level and without a previous history of jaundice. She had severe growth retardation, hepatosplenomegaly and generalized eczema. Progressive worsening of CLD was observed within 4 months. Investigations for etiology of liver disease were negative. Liver biopsy showed bridging necrosis, cholestasis and, cirrhosis. Recurrent immune hemolytic crisis and several viral infections developed in follow-up. She underwent whole cadaveric LT for end-stage liver disease (ESLD) 1 year after allogenic HSCT from a full matched related donor. The postoperative course was uneventful. The patient is alive with normal liver function and moderate skin graft versus host disease for 36 months after LT. In conclusion DOCK8 deficiency can be associated with severe CLD. Successful LT following HSCT is possible in patients with ESLD in DOCK8 deficiency. The timing of LT is challenging in patients requiring both HSCT and LT since conditioning regimens for HSCT can be highly hepatotoxic and the patients with suboptimal liver function can become decompensated during HSCT.

SCYL1 variants cause a syndrome with low γ-glutamyl-transferase cholestasis, acute liver failure, and neurodegeneration (CALFAN).

PURPOSE: Biallelic mutations in SCYL1 were recently identified as causing a syndromal disorder characterized by peripheral neuropathy, cerebellar atrophy, ataxia, and recurrent episodes of liver failure. The occurrence of SCYL1 deficiency among patients with previously undetermined infantile cholestasis or acute liver failure has not been studied; furthermore, little is known regarding the hepatic phenotype. METHODS: We aimed to identify patients with SCYL1 variants within an exome-sequencing study of individuals with infantile cholestasis or acute liver failure of unknown etiology. Deep clinical and biochemical phenotyping plus analysis of liver biopsies and functional studies on fibroblasts were performed. RESULTS: Seven patients from five families with biallelic SCYL1 variants were identified. The main clinical phenotype was recurrent low γ-glutamyl-transferase (GGT) cholestasis or acute liver failure with onset in infancy and a variable neurological phenotype of later onset (CALFAN syndrome). Liver crises were triggered by febrile infections and were transient, but fibrosis developed. Functional studies emphasize that SCYL1 deficiency is linked to impaired intracellular trafficking. CONCLUSION: SCYL1 deficiency can cause recurrent low-GGT cholestatic liver dysfunction in conjunction with a variable neurological phenotype. Like NBAS deficiency, it is a member of the emerging group of congenital disorders of intracellular trafficking causing hepatopathy.

Multiple Presentations of LRBA Deficiency: a Single-Center Experience.

INTRODUCTION: LPS-responsive beige-like anchor protein (LRBA) deficiency is a primary immunodeficiency categorized as common variable immunodeficiency associated with autoimmune manifestations and inflammatory bowel diseases; however, the clinical spectrum has been extended. Here, we present our cohort of Turkish LRBA-deficient patients from a single center, demonstrating a diversity of clinical manifestations. METHOD: Seven affected individuals from five families were assessed retrospectively in this study. RESULTS: Of the seven patients with LRBA deficiency, four had homozygous, and two had compound heterozygous mutations. One patient remained disease free until the last follow-up (age 17 years). The most common clinical manifestations of the six symptomatic patients were organomegaly (6/6), autoimmunity (6/6), and chronic diarrhea (5/6). Recurrent infectious episodes were observed in three patients. None of the patients had hypogammaglobulinemia at presentation. B cell subpopulation analysis revealed low numbers of switched-memory B cell numbers in two of the four tested patients. During the disease course, three of the patients died, two of them underwent successful hematopoietic stem cell transplantation (HSCT) from matched sibling donors, and one is under abatacept therapy. CONCLUSION: LRBA defects should always be kept in mind as a differential diagnosis for patients with autoimmune disease affecting multiple organs, chronic diarrhea, and organomegalies. In our experience, early HSCT is a life-saving therapeutic strategy.

Mesalamine Intolerance in Three Children with Crohn's Disease.

OBJECTIVE: To present the mesalamine-induced acute exacerbation of symptoms and inflammatory markers in children with Crohn's disease (CD). CLINICAL PRESENTATION AND INTERVENTION: Three children who presented with CD had acute exacerbation of colitis symptoms or elevated inflammatory markers when mesalamine was added to treatment while tapering/ceasing steroid treatment. While on steroid treatment, the patients maintained clinical and laboratory remission, but with the initiation of mesalamine treatment, they had abdominal pain and bloody mucoid diarrhoea and/or elevation of white blood cell count, C-reactive protein level and erythrocyte sedimentation rate. Bacterial pathogens were excluded from the urine, throat and blood cultures, parasites with stool examination, viral pathogens with serology. Within 3-7 days after the mesalamine treatment had been stopped, the patients showed improvement of colitis symptoms and normalisation of white blood cell count, C-reactive protein level and erythrocyte sedimentation rate. CONCLUSION: In this study mesalamine mimicked CD relapse in children with CD while tapering or after stopping steroid treatment. Awareness of this side effect of mesalamine could prevent a misdiagnosis of steroid dependency.

Yield of coeliac screening in abdominal pain-associated functional gastrointestinal system disorders.

AIM: Chronic abdominal pain (CAP) in childhood is common and in the majority functional. While CAP is one of the complaints of coeliac disease (CD), whether CAP as a sole complaint is indicative of CD is unclear. Our aim was to evaluate the relationship between CAP and CD. METHODS: The study was conducted on 1047 children (61.1% female, mean age 9.6 ± 4.1 years) with CAP. Patients were evaluated according to the Rome III criteria. Patients with alarm symptoms and conditions known to be associated with CD were excluded. Patients were screened for CD using a rapid tissue transglutaminase (tTG) test; positive cases were tested by tTG ELISA, and duodenal biopsies were obtained if tTG was above the normal limit. RESULTS: Functional dyspepsia (FD), irritable bowel syndrome (IBS) and functional abdominal pain (FAP) were diagnosed in 384 (36.7%), 274 (26.2%) and 389 (37.2%) patients, respectively. In 13 patients, the tTG rapid test was positive; 10 were also positive for tTG by ELISA and histopathological evaluations diagnosed CD in all 10 patients. The overall prevalence of CD was 0.95% (2.2%, 0.5% and 0.5% in patients with IBS, FD and FAP, respectively). The prevalence of CD in patients with IBS was higher than expected but with borderline statistical significance (P = 0.053). CONCLUSIONS: CD is found as common in children with FD and FAP as in the general population. CD was more commonly diagnosed in IBS patients with borderline statistical significance. We suggest that particular attention be paid to children with IBS.

Early-onset inflammatory bowel disease and common variable immunodeficiency-like disease caused by IL-21 deficiency.

BACKGROUND: Alterations of immune homeostasis in the gut can result in development of inflammatory bowel disease (IBD). Recently, Mendelian forms of IBD have been discovered, as exemplified by deficiency of IL-10 or its receptor subunits. In addition, other types of primary immunodeficiency disorders might be associated with intestinal inflammation as one of their leading clinical presentations. OBJECTIVE: We investigated a large consanguineous family with 3 children who presented with early-onset IBD within the first year of life, leading to death in infancy in 2 of them. METHODS: Homozygosity mapping combined with exome sequencing was performed to identify the molecular cause of the disorder. Functional experiments were performed to assess the effect of IL-21 on the immune system. RESULTS: A homozygous mutation in IL21 was discovered that showed perfect segregation with the disease. Deficiency of IL-21 resulted in reduced numbers of circulating CD19(+) B cells, including IgM(+) naive and class-switched IgG memory B cells, with a concomitant increase in transitional B-cell numbers. In vitro assays demonstrated that mutant IL-21(Leu49Pro) did not induce signal transducer and activator of transcription 3 phosphorylation and immunoglobulin class-switch recombination. CONCLUSION: Our study uncovers IL-21 deficiency as a novel cause of early-onset IBD in human subjects accompanied by defects in B-cell development similar to those found in patients with common variable immunodeficiency. IBD might mask an underlying primary immunodeficiency, as illustrated here with IL-21 deficiency.

Gastric carcinoid tumor in a 14-year old girl.

Gastric carcinoid tumors (GCT) are rare lesions that constitute 2.6-8.7% of all gastrointestinal carcinoids, mostly affect middle-aged females but the incidence in children is unknown. We present a 14-year-old girl, with GCT. She was treated with recombinant human growth hormone (GH) for complete GH deficiency, and endoscopy was performed to identify iron-deficiency anemia. Upper gastrointestinal endoscopy revealed a gastric polyp, and biopsies were compatible with GCT.

Cyclosporine-associated thrombotic microangiopathy and thrombocytopenia-associated multiple organ failure: a case successfully treated with therapeutic plasma exchange.

INTRODUCTION: Thrombotic microangiopathy (TMA) is characterized by microvascular thrombosis, thrombocytopenia, and microangiopathic hemolytic anemia. Previous studies have shown that cyclosporine (CsA) is associated with TMA but the number of reported cases is very limited. We describe a 13-year-old girl with CsA-associated TMA and thrombocytopenia-associated multiple organ failure (TAMOF). CASE REPORT: The patient was diagnosed with polyglandular deficiency syndrome and had a history of celiac disease, autoimmune thyroiditis, and diabetes mellitus type I. CsA was started 7 months before her admission to our pediatric intensive care unit for persistent diarrhea associated with celiac disease. At the time of her admission to our pediatric intensive care unit, she was thrombocytopenic and anemic with multiple organ failure. Laboratory and clinical findings were consistent with TMA and TAMOF. CsA was discontinued and therapeutic plasma exchange was performed daily for 5 days. The patient improved clinically, laboratory findings normalized, and TMA and multiple organ failure dissolved. CONCLUSION: This case report indicates that therapeutic plasma exchange may be effective in the treatment of CsA-associated TMA and TAMOF, especially in the presence of systemic findings.

Valproic acid-induced acute pancreatitis and multiorgan failure in a child.

Valproic acid (VPA) is still an important antiepileptic drug, with the broadest spectrum used in all types of seizures and syndromes. It has serious adverse effects such as hepatotoxicity, hyperammonemic encephalopathy, coagulation disorders, and pancreatitis. The incidence of VPA-associated pancreatitis has been estimated to be 1:40,000. We present a 6-year-old boy who developed acute pancreatitis (AP) and multiple-organ failure after 3 months of VPA therapy. The patient's laboratory values showed that his kidney and hepatic function had impaired and thrombocytopenia, and coagulopathy had developed. The patient's abdominal tomography showed a suspected appearance, which was consistent with pancreatitis. Because amylase and lipase levels were found to be high, AP was considered. The patient improved after cessation of VPA treatment. Ten days later, the patient recovered both clinically and laboratorial. Consequently, the patient was discharged with cure. In conclusion, AP is a rare, severe adverse reaction to VPA treatment. If a child, who is receiving VPA, develops abdominal pain and vomits, VPA-associated pancreatitis must be considered.