Circulating Serum Cystatin C as an Independent Risk Biomarker for Vascular Endothelial Dysfunction in Patients with COVID-19-Associated Multisystem Inflammatory Syndrome in Children (MIS-C): A Prospective Observational Study.

INTRODUCTION: Multisystem inflammatory syndrome in children (MIS-C) is a new clinical entity that has emerged in the context of the COVID-19 pandemic. Despite the less severe course of the disease, varying degrees of cardiovascular events may occur in MIS-C; however, data on vascular changes occurring in MIS-C are still lacking. Endothelial dysfunction (ED) is thought to be one of the key risk factors contributing to MIS-C. BACKGROUND: We conducted a prospective observational study. We investigated possible manifestations of cardiac and endothelial involvement in MIS-C after the treatment of the acute stage and potential predictive biomarkers in patients with MIS-C. METHODS: Twenty-seven consecutive pediatric subjects (≥9 years), at least three months post-treated MIS-C of varying severity, in a stable condition, and twenty-three age- and sex-matched healthy individuals (HI), were enrolled. A combined non-invasive diagnostic approach was used to assess endothelial function as well as markers of organ damage using cardiac examination and measurement of the reactive hyperemia index (RHI), by recording the post- to pre-occlusion pulsatile volume changes and biomarkers related to ED and cardiac disease. RESULTS: MIS-C patients exhibited a significantly lower RHI (indicative of more severe ED) than those in HI (1.32 vs. 1.80; p = 0.001). The cutoff of RHI ≤ 1.4 was independently associated with a higher cardiovascular risk. Age and biomarkers significantly correlated with RHI, while serum cystatin C (Cys C) levels were independently associated with a diminished RHI, suggesting Cys C as a surrogate marker of ED in MIS-C. CONCLUSIONS: Patients after MIS-C display evidence of ED, as shown by a diminished RHI and altered endothelial biomarkers. Cys C was identified as an independent indicator for the development of cardiovascular disease. The combination of these factors has the potential to better predict the cardiovascular consequences of MIS-C. Our study suggests that ED may be implicated in the pathophysiology of this disease.

Karyotyping of Lymphocytes and Epithelial Cells of Distinct Embryonic Origin Does Not Help to Predict the Turner Syndrome Features.

BACKGROUND: In Turner syndrome (TS), fluorescent in situ hybridization (FISH) karyotyping offers an alternative to classical karyotyping. OBJECTIVE: We tested the added value of FISH karyotyping from lymphocytes (mesodermal origin), buccal cells (ectodermal origin), and a rear-tongue smear (endodermal origin) to determine the 45,X cell line fraction and its impact on patient phenotype. DESIGN AND PATIENTS: Classical karyotyping and three FISH assays were done in 153 girls and women previously diagnosed with TS in four university hospitals. The 45,X cell line fraction was determined for each method and correlated with the major phenotypic signs. RESULTS: Classical karyotyping identified 45,X/46,XX mosaicism in 77/153 subjects (50%), 45,X monosomy in 52/153 (34%), and other karyotypes in 24/153 (16%). FISH from lymphocytes verified 45,X in 47/52 original cases, whereas 4/52 had 45,X/46,XX and 1/52 45,X/47,XYY mosaicism. The 45,X cell line fraction was higher in FISH from lymphocytes compared to classical karyotyping (median 86.4% vs. 70.0%; p < 0.001), while there was no difference for FISH from buccal or rear-tongue smear cells. The mean 45,X cell line fraction was more abundant in patients with several of the characteristic phenotypic signs compared to patients without them (p < 0.01), but the predictive power was insufficient. CONCLUSION: FISH analysis confirmed the findings of classical karyotyping; only a few 45,X monosomy cases were reclassified as mosaics. The 45,X cell line fraction did not show clinically meaningful prediction of the phenotype. FISH analysis of buccal or rear-tongue epithelial cells may be a non-inferior, less invasive alternative to classical karyotyping.

Haplotype analysis of the X chromosome in patients with Turner syndrome in order to verify the possible effect of imprinting on selected symptoms.

AIMS: Turner syndrome is the only chromosome monosomy that is postnatally compatible with life. The reported incidence of TS is 1 in 2500 liveborn girls. The phenotype of these girls is highly variable, with cardiac abnormalities being life-threatening defects. The aim of the study was to reveal the possible influence of the parental origin of the X chromosome in these patients on a selected phenotype that is associated with Turner syndrome. Selected symptoms and parameters were: a bicuspid aortic valve, aortic coarctation, lymphoedema, pterygium colli, coeliac disease, thyroiditis, otitis media, diabetes mellitus 2, renal abnormalities, spontaneous puberty, and IVF. METHODS: The X chromosome haplotype was determined for a group of 45,X patients verified by native FISH. A molecular diagnostic method based on the detection of different lengths of X chromosome-linked STR markers using the Argus X-12 QS kit was used to determine the X haplotype. RESULTS: Our results, analysed by Fisher's exact (factorial) test, suggest independence between the maternal/paternal origin of the inherited X chromosome and the presence of the anomalies that were studied (P=1 to P=0.34). CONCLUSION: In the group of 45,X patients, who were precisely selected by means of the native FISH method, no correlation was demonstrated with the parental origin of the X chromosome and the observed symptom.

Major heart defects: the diagnostic evaluations of first-year-olds.

BACKGROUND: Severe or critical congenital heart defects (CHDs) constitute one third of the heart defect cases detected only after birth. These prenatally unrecognised defects usually manifest as cyanotic or acyanotic lesions and are diagnosed postnatally at various times. The aim of the study was to identify their clinical symptoms and determine individual risk periods for CHD manifestation. METHODS: Data were assessed retrospectively based on a cohort of patients born between 2009 and 2018 in a population of 175,153 live births. Occurrence of the first symptoms of CHD was classified into: early neonatal (0-7 days), late neonatal (8-28 days), early infancy (1-6 months), or late infancy (6-12 months). The first symptom for which the child was referred to a paediatric cardiologist was defined as a symptom of CHD. RESULTS: There were 598 major CHDs diagnosed in the studied region, 91% of which were isolated anomalies. A concomitant genetic disorder was diagnosed in 6% of the cases, while 3% presented extracardiac pathology with a normal karyotype. In total, 47% (282/598) of all CHDs were not identified prenatally. Of these, 74% (210/282) were diagnosed as early neonates, 16% (44/282) as late neonates, and 10% (28/282) as infants. The most common symptoms leading to the diagnosis of CHD were heart murmur (51%, 145/282) and cyanosis (26%, 73/282). Diagnosis after discharge from the hospital occurred in 12% (72/598) of all major CHDs. Ventricular septal defect and coarctation of the aorta constituted the majority of delayed diagnoses. CONCLUSIONS: In conclusion, murmur and cyanosis are the most common manifestations of prenatally undetected CHDs. Although most children with major CHDs are diagnosed as neonates, some patients are still discharged from the maternity hospital with an unidentified defect.

Fetal heart rhabdomyomatosis: a single-center experience.

Objectives: The primary aim of the study was to evaluate the prevalence of fetal heart tumors in a single tertiary referral center over a period of 15 years. The secondary aim was to confirm the presence of tuberous sclerosis complex (TSC) through the evaluation of germline mutation in TSC1/TSC2 and assess the outcomes in affected fetuses and newborns.Methods: A retrospective study was conducted between 2003 and 2017. Fetal echocardiography was performed in the second trimester of pregnancy in the study population. The identification of heart tumors and further follow-up were performed by a pediatric cardiologist. Molecular genetic analysis was conducted on fetuses and children in cases where TSC was suspected.Results: In total, 39,018 fetuses were examined between 2003 and 2017. Heart tumors were detected in nine fetuses and were diagnosed as rhabdomyoma in all cases. We identified mutations in one of the TSC1 or TSC2 genes in all cases with multiple rhabdomyomas (8/9). In all born children (5/9), the genetically confirmed diagnosis of TSC was established, and clinically pathological deposits in the brain were found.Conclusion: Fetal heart tumors are usually represented by rhabdomyomas having a good cardiac prognosis. However, rhabdomyoma is usually the first symptom of TSC with a subsequent brain disorder and impaired neurological development.

Associations between congenital heart defects and genetic and morphological anomalies. The importance of prenatal screening.

AIM: To study congenital heart defects (CHDs), evaluate their relation to extra-cardiac pathologies, and assess the significance of prenatal diagnostics for heart diseases. METHODS: Data from 1999-2017 were analyzed for the incidence of significant CHDs in fetuses (prenatal ultrasound/echocardiography) and children, including, where applicable, autopsy data and genetic evaluation. RESULTS: Among 220,400 fetuses, 819 (3.7 cases per 1000) significant CHDs were observed. Of the total, 53% (435/819) of CHDs were diagnosed prenatally. The heart defect was an isolated impairment in 78% (640/819), associated with a genetic impairment in 16% (128/819), and with extra-cardiac malformations without genetic pathology in 6% (51/819). Chromosomal aberrations were diagnosed prenatally in 70% (90/128) of those affected and extra-cardiac conditions in 86% (44/51). The CHD and genetic pathology association was more frequent prenatally [21% (90/435) vs. postnatally: 10% (38/384; P<0.0001)], as was the association between CHD with other extra-cardiac pathology and a normal karyotype [prenatally: 10% (44/435) vs. postnatally: 2% (7/384; P<0.0001)]. CONCLUSION: Heart defects are most frequently isolated, with genetic and other extra-cardiac anomalies in about one third of cases, significantly linked to prenatal diagnostics.

Increased prevalence of bicuspid aortic valve in Turner syndrome links with karyotype: the crucial importance of detailed cardiovascular screening.

BACKGROUND: Bicuspid aortic valve (BAV) represents one of the strongest risk factors for aortic dissection in Turner syndrome (TS). An exact relation between the occurrence of BAV and a particular karyotype has not been established yet. The aim of this study was to determine the association between karyotype and prevalence of BAV. METHODS: Sixty-seven TS patients aged between 6.6 and 32.5 years underwent cardiac magnetic resonance imaging (MRI) study. They were divided into four cytogenetic subgroups-45,X karyotype (n=27); 45,X/46,XX mosaicism (n=17); structural abnormalities of the X chromosome (n=10); and 45,X/structural abnormality of the X chromosome mosaicism (n=13). Prevalence of BAV and odds ratio (OR) compared with the general population in the whole study group, and statistical comparison of prevalences of BAV among the individual subgroups were determined. RESULTS: Prevalence of BAV in the whole study group was established as 28.4% [OR 208.3 (95% CI - 103.8-418.0); p-value<0.0001]. Individuals with 45,X karyotype had the highest prevalence of BAV - 40.7%, p-value<0.0001. Presence of any 45,X cell line in karyotype significantly predisposed to BAV (p-value=0.05). CONCLUSIONS: The 45,X karyotype is associated with the highest prevalence of BAV. Also, the presence of the 45,X cell line in any mosaic karyotype increases the probability of BAV.