Identification of the molecular etiology in rare congenital hemolytic anemias using next-generation sequencing with exome-based copy number variant analysis.

OBJECTIVES: In congenital hemolytic anemias (CHA), it is not always possible to determine the specific diagnosis by evaluating clinical findings and conventional laboratory tests. The aim of this study is to evaluate the utility of next-generation sequencing (NGS) and clinical-exome-based copy number variant (CNV) analysis in patients with CHA. METHODS: One hundred and forty-three CHA cases from 115 unrelated families referred for molecular analysis were enrolled in the study. Molecular analysis was performed using two different clinical exome panels in 130 patients, and whole-exome sequencing in nine patients. Exome-based CNV calling was incorporated into the traditional single-nucleotide variant and small insertion/deletion analysis pipeline for NGS data in 92 cases. In four patients from the same family, the PK Gypsy variant was investigated using long-range polymerase chain reaction. RESULTS: Molecular diagnosis was established in 86% of the study group. The most frequently mutated genes were SPTB (31.7%) and PKLR (28.5%). CNV analysis of 92 cases revealed that three patients had different sizes of large deletions in the SPTB and six patients had a deletion in the PKLR. CONCLUSIONS: In this study, NGS provided a high molecular diagnostic rate in cases with rare CHA. Analysis of the CNVs contributed to the diagnostic success.

Drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome secondary to antimicrobial therapy in pediatric bone and joint infections.

Background: Bone and joint infections are common in children, particularly those under 10 years of age. While antimicrobial therapy can often successfully treat these infections, surgical drainage may also be necessary. It is important to note that prolonged courses of treatment have been associated with adverse events and drug reactions. Among these, drug reactions with eosinophilia and systemic symptoms (DRESS) syndrome is particularly severe and potentially life-threatening. We aimed to evaluate the cases of DRESS syndrome that develop during the treatment of bone and joint infections. Methods: A retrospective study was conducted at a tertiary-level university hospital between 2015 and 2022 to determine the incidence and outcomes of definite DRESS Syndrome in children under 18 years of age with bone and joint infections. Results: Of 73 patients with bone and joint infections, 16 (21.9 %) children developed antimicrobial therapy-induced DRESS syndrome. Eight (50 %) of these children were boys; the mean age of the patients was 9.76 ± 5.5 years. DRESS syndrome occurred in 16 children, including 13 children with osteomyelitis, 1 child with osteomyelitis and septic arthritis, and 2 children with septic arthritis and sacroiliitis. The mean duration of intravenous antibiotic therapy was 40.6 ± 16.6 days; the mean hospital stay was 48.7 ± 23.7 days; the mean time for the development of DRESS syndrome after starting antibiotics was 19.6 ± 7.68 days. New onset fever (68.8 %) and rash (43.8 %) were the most common symptoms of DRESS Syndrome. Cefotaxime and vancomycin were drugs responsible for DRESS syndrome in 8 (50 %) of 16. The causative antibiotics were switched to another class of antibiotic, most commonly preferred was ciprofloxacin (n:5; 31.3 %). For children with persistent symptoms, steroids were used in 5 (31.25) patients. Conclusions: Clinicians should be aware of DRESS syndrome in children who develop fever and rash under long-term antibiotics and should check hematological and biochemical parameters to predict the severity of DRESS syndrome. In patients with persistent symptoms, steroids may be used to control the symptoms.

Dual Diagnosis of Trichohepatoenteric Syndrome and Lipoid Proteinosis in a Turkish Child.

Introduction: Trichohepatoenteric syndrome (THES) is caused by pathogenic mutations in TTC37 and SKIV2L genes and characterized by intractable diarrhea, facial dysmorphism, hair abnormality, immunodeficiency, and skin abnormalities. Lipoid proteinosis is caused by pathogenic mutations in ECM1 gene and characterized by deposition of hyaline-like material in various tissues resulting in heterogenous clinical findings. Case Presentation: Four years after the diagnosis and management of THES, due to new clinical findings, another reason for underlying features of the patient was considered. WES was performed and a homozygous c.507delT (p.Arg171GlyfsTer7) mutation in the ECM1 gene was detected. Conclusion: This case provides an example of co-existence of multiple genetic defects in a single patient born to consanguineous parents.

SARS-CoV-2 reinfections in the pediatric cohort-a single-center experience.

BACKGROUND: This study focused on timelines of infection episodes and dominant variants and aims to determine disease severity and outcome of pediatric patients with reinfection. MATERIALS AND METHODS: This study retrospectively evaluated the medical records of the hospitalized patients and/or outpatients aged 0-18 with a positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) polymerase chain reaction between March 2020 and September 2022 at Ege University Children's Hospital. RESULTS: Ninety-one pediatric patients reinfected with SARS-CoV-2 were included in the study. There was an underlying disease in 26.4% of the patients. The median time between the two infection episodes was 184 (90-662) days. There were 24 patients (26.3%) with the first infection in pre-Delta period; 17 (18.6%) of them were reinfected in Omicron BA.1 period, while 7 (7.6%) in Omicron BA.4/BA.5 period. Forty-five patients (49.4%) were infected initially in the Delta period; 35 patients (38.4%) were reinfected in the Omicron BA.1 period, while 10 patients (10.9%) were reinfected in the Omicron BA.4/BA.5 period. Twenty-two patients (24.1%) had the first infection in the Omicron BA.1 period and then reinfected in the Omicron BA.4/BA.5 period. Patients with reinfection more frequently displayed a symptom (84.6% vs. 94.5%, p = 0.03). The hospitalization rate significantly declined in reinfection (15.3% vs. 7.6%, p = 0.03). Severe disease, treatment needs and steroid use were decreased in reinfections without a significant difference (p > 0.05). Intensive care unit admission was not altered. CONCLUSION: This study revealed that reinfections frequently develop in previously healthy children but do not cause more severe outcomes. The risk of symptomatic reinfections is still high due to the effect of the Omicron variant.

Molecular diagnosis in patients with monogenic diabetes mellitus, and detection of a novel candidate gene.

AIM: We aimed to investigate molecular genetic basis of monogenic diabetes (DM) and novel responsible candidate genes with targeted Next Generation Sequencing (NGS) and Whole Exome Sequencing (WES). METHODS: A hundred cases presenting with clinical findings and a family history of monogenic DM were included in the study. Molecular analysis was performed using an NGS panel including 14 genes. Following targeted NGS, WES was planned in cases in whom no variant was detected. RESULTS: Thirty different disease-causing variants in seven different genes were detected in thirty-five (35 %) cases with targeted NGS approach. Most common pathogenic variant was found in GCK gene in 25 (25 %) cases. Four different variants were detected in 4 (4 %) patients in ABCC8 gene. In 45 of 65 cases; WES analyses were done. A heterozygous c.2635C > T(p.Gln879Ter) variant was detected in IFIH1 gene in a patient with incidental hyperglycemia. In the segregation analysis affected mother was shown to be heterozygous for the same variant. CONCLUSION: Molecular etiology was determined in 35 % cases with the NGS targeted panel. Seventeen novel variants in monogenic DM genes have been identified. A candidate gene determined by WES analysis in a case that could not be diagnosed with NGS panel in this study.

The clinical phenotype of Koolen-de Vries syndrome in Turkish patients and literature review.

Koolen-de Vries syndrome (KdVS) is a rare multisystemic disorder caused by a microdeletion on chromosome 17q21.31 including KANSL1 gene or intragenic pathogenic variants in KANSL1 gene. Here, we describe the clinical and genetic spectrum of eight Turkish children with KdVS due to a de novo 17q21.31 deletion, and report on several rare/new conditions. Eight patients from unrelated families aged between 17 months and 19 years enrolled in this study. All patients evaluated by a clinical geneticist, and the clinical diagnosis were confirmed by molecular karyotyping. KdVS patients had some common distinctive facial features. All patients had neuromotor retardation, and speech and language delay. Epilepsy, structural brain anomalies, ocular, ectodermal, and musculoskeletal findings, and friendly personality were remarkable in more than half of the patients. Hypertension, hypothyroidism, celiac disease, and postaxial polydactyly were among the rare/new conditions. Our study contributes to the clinical spectrum of patients with KdVS, while also provide a review by comparing them with previous cohort studies.

Misdiagnosis of multisystem inflammatory syndrome in children: A diagnostic challenge.

AIMS: As the COVID-19 pandemic continues, multisystem inflammatory syndrome in children (MIS-C) maintains its importance in the differential diagnosis of common febrile diseases. MIS-C should be promptly diagnosed because corticosteroid and/or intravenous immunoglobulin treatment can prevent severe clinical outcomes. In this study, we aimed to evaluate clinical presentation, diagnostic parameters and management of MIS-C and compare its clinical features to those of common febrile disease. METHODS: This study was conducted at a tertiary-level university hospital between December 2020 and October 2022. One hundred and six children who were initially considered to have MIS-C disease were included in the study. During the follow-up period in the hospital, when the clinical and laboratory findings were re-evaluated, 38 out of 106 children were diagnosed differently. The clinical and laboratory findings of 68 children followed up with the diagnosis of MIS-C and 38 children who were initially misdiagnosed as MIS-C but with different final diagnoses were retrospectively compared. RESULTS: We identified 68 patients with MIS-C and 38 patients misdiagnosed as MIS-C during the study period. Infectious causes (71%), predominantly bacterial origin, were the most frequently confused conditions with MIS-C. Patients with MIS-C were older and had a more severe clinical course with high rates of respiratory distress, shock, and paediatric intensive care unit admission. While rash and conjunctivitis were more common among patients with MIS-C, cough, abdominal pain and diarrhoea were observed more frequently in patients misdiagnosed as MIS-C. Lower absolute lymphocyte counts, platelet counts and higher C-reactive protein and fibrinogen levels, pathological findings on echocardiography were the distinctive laboratory parameters for MIS-C. Multivariate analysis showed that older age, presence of conjunctivitis, high level of serum CRP and lower platelets were the most discriminative predictors for the diagnosis of MIS-C. CONCLUSION: There are still no specific findings to diagnose MIS-C, which therefore can be confused with different clinical conditions. Further data are needed to assist the clinician in the differential diagnosis of MIS-C and the diagnostic criteria should be updated over time.

Electrocardiographic changes in hospitalised children with COVID-19.

OBJECTIVES: Cardiac manifestations of the coronavirus disease 2019 (COVID-19) have mainly been reported in adults. Therefore, we aimed to determine the electrocardiographic abnormalities in hospitalised paediatric patients with COVID-19 and multisystemic inflammatory syndrome in children. METHODS: We retrospectively evaluated hospitalised paediatric patients <18 years of age with a diagnosis of COVID-19 (n = 168) and multisystem inflammatory syndrome in children (n = 48) between March 2021 and December 2021. A daily electrocardiography was performed for the patients who had electrocardiographic abnormalities on admission or developed electrocardiographic abnormality on the follow-up. The characteristics of these patients, underlying predisposing conditions, and clinical course were also examined. RESULTS: Two-hundred sixteen paediatric patients (55% were male) with a mean age of 10.7 ± 4.69 years were evaluated. There was an underlying disease in 84 (38.8%) patients and 51 (23.6%) required paediatric ICU admission. Electrocardiography abnormality was detected in 12 (5.5%) which were as follows: 7 (3.2%) had sinus bradycardia, 3 (1.4%) patients had transient ST elevation and concomitant T negativity, and 2 (0.9%) developed first-degree Atrioventricular (AV) block. The median time from the onset of disease symptoms to detecting electrocardiographic abnormality was 9 days. Electrocardiographic abnormalities returned to normal uneventfully 3 days later. CONCLUSIONS: The prevalence of arrhythmia in paediatric patients with COVID-19 was detected in 5.5% of the patients. While two-thirds of the electrocardiography abnormalities were sinus bradycardia, ST elevation was remarkable (1.4%). Clinicians should be aware of electrocardiographic abnormalities and consider electrocardiographic monitoring in paediatric patients with COVID-19 and multisystemic inflammatory syndrome in children.

Cardiac Assessment in Children with MIS-C: Late Magnetic Resonance Imaging Features.

Multisystem Inflammatory Syndrome (MIS-C) is a new entity that emerges 2-4 weeks after the SARS-CoV-2 infection in children. MIS-C can affect all systems, the most severe of which is cardiac involvement. The duration of the cardiac symptoms is still uncertain and may be persistent or prolonged. The American College of Rheumatology Clinical Guidelines recommends cardiac magnetic resonance imaging (MRI) 2-6 months after the diagnosis of MIS-C in patients presenting with significant transient left ventricular (LV) dysfunction in the acute phase of illness (LV ejection fraction 50%) or persistent LV dysfunction. There are a few studies investigating cardiac MRI findings in MIS-C patients. In this study, we aimed to evaluate cardiac MRI findings, at the earliest 3 months after diagnosis, and compare these findings with the echocardiograms in children with MIS-C. A retrospective study including 34 MIS-C patients was conducted at a tertiary-level University Hospital between June 2020 and July 2021. Centers for Disease Control and Prevention criteria were used in the diagnosis of MIS-C. Cardiac MRI was performed at least 3 months after MIS-C diagnosis. The study included 17 (50%) boys and 17 (50%) girls with a mean age of 9.31 ± 4.72 years. Initial echocardiographic evaluation revealed cardiac abnormality in 13 (38.2) patients; 4 (11.8%) pericardial effusion, 4 (11.8%) left ventricular ejection fraction (LVEF) < 55%, and 5 (14.7%) coronary artery dilatation. Echocardiography showed normal LV systolic function in all patients during follow-up; coronary dilatation persisted in 2 of 5 (40%) patients at the 6th-month visit. Cardiac MRI was performed in 31 (91.2%) patients, and myocardial hyperemia was not detected in any patients (T1 relaxation time was < 1044 ms in all children). However, 9 (29%) patients' MRI showed isolated elevated T2 levels, and 19 (61.3%) revealed at least one of the following findings: pericardial effusion, right ventricular dysfunction, or LVEF abnormality. In patients with MIS-C, a high rate of cardiac involvement, particularly pericardial effusion was determined by cardiac MRI performed at the earliest 2-6 months after diagnosis. Even if echocardiography does not reveal any abnormality in the initial phase, cardiac MRI should be suggested in MIS-C patients in the late period. This is the first study reporting cardiac MRI findings in the late period of MIS-C patients.

Quantitative Antibody Levels Against SARS-CoV-2 Spike Protein in COVID-19 and Multisystem Inflammatory Syndrome in Children.

The majority of children with coronavirus diseases 2019 (COVID-19) are asymptomatic or develop mild symptoms, and a small number of patients require hospitalization. Multisystem inflammatory syndrome in children (MIS-C) is one of the most severe clinical courses of COVID-19 and is suggested to be a hyperinflammatory condition. This study aimed to compare quantitative antibody levels against SARS-CoV-2 spike protein in children with COVID-19 and MIS-C. Blood samples from 75 patients [n = 36 (48%) with mild/asymptomatic (group 1), n = 22 (29.3%) with moderate-to-severe SARS-CoV-2 infection (group 2) and n = 17 (22.6%) patients with MIS-C (group 3)] were analyzed 3 months after COVID-19. The majority of the children with asymptomatic/mild COVID-19 symptoms (80.6%), moderate/severe disease (90.9%), and MIS-C (82.4%) had detectable IgG antibodies to SARS-CoV-2 spike protein (p = 0.567). The mean antibody value against SARS-CoV-2 spike protein was 321.9 ± 411.6 in group 1, 274 ± 261 in group 2, and 220 ± 299 in group 3, respectively (p > 0.05). Patients diagnosed with COVID-19 (asymptomatic/mild+moderate/severe) and those with MIS-C were also compared; the antibody positivity rates [COVID-19 group: 85.5%, MIS-C group: 82.4%, (p = 0.833)] and mean antibody values [COVID-19 group: 303.9 ± 360.3, MIS-C group: 220 ± 299, (p > 0.05)] were similar in both groups. In conclusion, the majority of children with COVID-19 and MIS-C developed a detectable antibody level against SARS-CoV-2 spike protein 3 months after COVID-19. Quantitative antibody levels were similar in both asymptomatic/mild disease, moderate/severe disease, and MIS-C group. Long-term studies evaluating antibody responses in children with COVID-19 and MIS-C are needed for more accurate vaccine schedules.

LSM1 is the new candidate gene for neurodevelopmental disorder.

Neurodevelopmental disorders are a heterogeneous group of diseases. Clinical presentation often overlaps with neurodevelopmental disorders, and explaining the molecular origin often requires reverse phenotyping. Next-Generation Sequencing (NGS) allows fast and cost-effective high-throughput sequencing. Given this fact, NGS is a useful tool for reverse phenotyping, especially for rare diseases. We hereby present two similarly affected siblings with neurodevelopmental delay. Duo-whole exome sequencing was performed. The homozygous LSM1 variant was found as the most likely cause for the condition. Our report contributes to the literature on the phenotype the biallelic LSM1 mutations. Moreover, we highlight the importance of reverse phenotyping and reanalysis of the genetic data.

Biallelic variants in ADAMTS15 cause a novel form of distal arthrogryposis.

PURPOSE: We aimed to identify the underlying genetic cause for a novel form of distal arthrogryposis. METHODS: Rare variant family-based genomics, exome sequencing, and disease-specific panel sequencing were used to detect ADAMTS15 variants in affected individuals. Adamts15 expression was analyzed at the single-cell level during murine embryogenesis. Expression patterns were characterized using in situ hybridization and RNAscope. RESULTS: We identified homozygous rare variant alleles of ADAMTS15 in 5 affected individuals from 4 unrelated consanguineous families presenting with congenital flexion contractures of the interphalangeal joints and hypoplastic or absent palmar creases. Radiographic investigations showed physiological interphalangeal joint morphology. Additional features included knee, Achilles tendon, and toe contractures, spinal stiffness, scoliosis, and orthodontic abnormalities. Analysis of mouse whole-embryo single-cell sequencing data revealed a tightly regulated Adamts15 expression in the limb mesenchyme between embryonic stages E11.5 and E15.0. A perimuscular and peritendinous expression was evident in in situ hybridization in the developing mouse limb. In accordance, RNAscope analysis detected a significant coexpression with Osr1, but not with markers for skeletal muscle or joint formation. CONCLUSION: In aggregate, our findings provide evidence that rare biallelic recessive trait variants in ADAMTS15 cause a novel autosomal recessive connective tissue disorder, resulting in a distal arthrogryposis syndrome.

Clinical and Laboratory Findings of SARS-CoV-2 Infection in Children Younger than 6 Months Old: Neutropenia is More Common Not Lymphopenia.

BACKGROUND: Studies on age-related differences in clinical and laboratory features of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection are limited. We aimed to evaluate the demographic, clinical, laboratory findings of SARS-CoV-2 infection in children younger than 6 months old and compare them with older children. METHODS: A single-center retrospective study, including 209 confirmed SARS-CoV-2 infection cases, was conducted between 11 March 2020 and 1 September 2021. The case group consisted of 47 patients younger than 6 months old, whereas the control group consisted of 162 patients older than 6 months old. RESULTS: The mean age of the case group was 2.77 ± 1.52 months, and the control group was 101.89 ± 65.77 months. Cough was statistically higher in the control group, and poor feeding was higher in the case group (p = 0.043, 0.010). The underlying disease rate was statistically higher in the control group; however, the hospitalization rate was higher in the case group (p = 0.036, 0.001). The case group had significantly lower median values of the absolute neutrophil count, hemoglobin and higher median values of white blood cell, absolute lymphocyte count and platelet than the control group (p < 0.05). C-reactive protein, fibrinogen values were significantly lower, and procalcitonin, D-dimer, troponin T, N-terminal pro-B-type natriuretic peptide significantly higher in the case group (p < 0.05). Lymphopenia was more common in the control group, whereas neutropenia was more common in the case group (p = 0.001, 0.011). CONCLUSIONS: We showed that most children younger than 6 months old had mild and asymptomatic SARS-CoV-2 infection; however, the hospitalization rate was higher, and neutropenia was more common in older children. Lay summaryStudies on age-related differences in clinical and laboratory features on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in pediatric patients are limited. We aimed to evaluate the demographic, clinical and laboratory findings of SARS-CoV-2 infection in children younger than 6 months old and compare them with older children. A single-center retrospective study was conducted, including 209 SARS-CoV-2 infection cases. The case group consisted of 47 patients younger than 6 months old, and the control group consisted of 162 patients older than 6 months old. Most children younger than 6 months old had mild and asymptomatic SARS-CoV-2 infection; however, the hospitalization rate was higher than older children. Neutropenia was more common in patients younger than 6 months than older children with SARS-CoV-2 infection, even if underlying diseases were excluded.

Autosomal Recessive Primary Microcephaly (MCPH) and Novel Pathogenic Variants in ASPM and WDR62 Genes.

Introduction: Autosomal recessive primary microcephaly (MCPH) is a disorder characterized by congenital microcephaly and intellectual disability without extra-central nervous system malformation. MCPH is a disease with heterogeneity in genotype and phenotype. For this reason, it is important to determine the genetic causes and genotype-phenotype relationship in MCPH, which causes lifelong impairment. In this study, we aimed to evaluate the clinical, genetic, and brain imaging findings of cases diagnosed with MCPH. Methods: Electroencephalogram and brain magnetic resonance imaging were performed for all cases. We evaluated genetic results of the 39 families including cases with suspected MCPH diagnosis. Results: Genetic diagnosis related to MCPH was provided in 11/39 (28.2%) of these families including 13/41 cases (31.7%). Variants of the WDR62 gene were the most common (61.5%) cause, and variants of the ASPM gene were the second most common cause (38.5%). We have found 6 novel variants and 4 previously reported variants in ASPM and WDR62 genes. Main brain imaging findings in our cases were lissencephaly, polymicrogyria, schizencephaly, pachygyria, and cortical dysplasia. Genetic counseling in 2 families whose genetic diagnosis was determined prevented them from having another child with MCPH. Discussion/Conclusion: Detection and reporting of novel variants is an important step in eliminating this disorder by providing families with appropriate genetic counseling.

The longitudinal evaluation of COVID-19 in pediatric patients and the impact of delta variant.

BACKGROUND: Pediatric patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) displayed milder symptoms than adults. However, they play an important role in case numbers and virus transmission. Therefore, we aimed to determine the epidemiological features of all pediatric patients infected with SARS-CoV-2 and put forth case numbers longitudinally throughout the delta variant dominant period. METHODS: A retrospective study was conducted at a university hospital and included patients between 0 and18 years old with a SARS-CoV-2 polymerase chain reaction (PCR) positive result, including inpatients and outpatients. Epidemiological and clinical features were recorded from electronic files, and telephone visits were performed between March 2020 and December 2021. RESULTS: During the study period, 3175 coronavirus disease 2019 (COVID-19) pediatric patients were admitted to our hospital with a mean age of 10.61 ± 4.6 years. Of the 1815 patients who could be interviewed, 85.7% reported at least one symptom. Before the delta variant period, 0-4 years aged children were more commonly infected, while school-aged children and adolescents were more common, and the rate of pediatric cases to all COVID-19 cases increased to 35.8% after the delta variant became dominant. Symptomatic cases were significantly higher before the delta variant (87.8% vs. 84.06%, p = 0.016). The hospitalization rate was higher before the delta variant (p < 0.001), whereas PICU admission showed no statistical difference. CONCLUSIONS: The frequency of school-aged children and adolescents raised with the impact of both school openings and the delta variant, and the rate of pediatric cases increased in total COVID-19 patient numbers.