Publications by authors named "Jan Lebl"

The purpose of this study is to elucidate the genetic causes and phenotypic presentation of nonfamilial tall stature (nFTS) and to compare these findings with those of familial tall stature (FTS) from the same population that was previously studied. Children with nFTS (defined as a height >  + 2 SDs with both parents' heights <  + 2 SDs) underwent endocrine and anthropometric examinations and genetic testing (karyotyping, SHOX gene dosage analysis and next-generation sequencing of 786 growth-associated genes). Exome sequencing was performed in patients with negative genetic results and a height >  + 3 SDs.

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Introduction: Prader-Willi syndrome (PWS) is primarily caused by a paternal microdeletion of the 15q11-q13 region, maternal uniparental disomy (mUPD) or unbalanced translocations. The gene, located within 15q11-q13, is a master regulator of pubertal initiation. We aimed to compare variant pubertal onset and progression with recent normative data and to correlate it with abnormal gene status.

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Objectives: Subsequent to early life feeding issues, children with Prader-Willi syndrome (PWS) develop hyperphagia and severe obesity. Growth hormone (GH) therapy has been approved in PWS to improve growth, body composition, and BMI. We aimed to clarify the role of age at GH therapy onset on growth and BMI trajectories in children with PWS.

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Predicting and quantifying phenotypic consequences of genetic variants in rare disorders is a major challenge, particularly pertinent for 'actionable' genes such as thyroid hormone transporter MCT8 (encoded by the X-linked SLC16A2 gene), where loss-of-function (LoF) variants cause a rare neurodevelopmental and (treatable) metabolic disorder in males. The combination of deep phenotyping data with functional and computational tests and with outcomes in population cohorts, enabled us to: (i) identify the genetic aetiology of divergent clinical phenotypes of MCT8 deficiency with genotype-phenotype relationships present across survival and 24 out of 32 disease features; (ii) demonstrate a mild phenocopy in ~400,000 individuals with common genetic variants in MCT8; (iii) assess therapeutic effectiveness, which did not differ among LoF-categories; (iv) advance structural insights in normal and mutated MCT8 by delineating seven critical functional domains; (v) create a pathogenicity-severity MCT8 variant classifier that accurately predicted pathogenicity (AUC:0.91) and severity (AUC:0.

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Genetic factors play a crucial role in determining human height. Short stature commonly affects multiple family members and therefore, familial short stature (FSS) represents a significant proportion of growth disorders. Traditionally, FSS was considered a benign polygenic condition representing a subcategory of idiopathic short stature (ISS).

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Article Synopsis
  • Previous recommendations on diagnosing familial renal glucosuria lacked a comprehensive understanding of glucosuria's differential diagnosis.
  • This review aims to summarize the various causes of glucosuria and propose an evidence-based diagnostic approach for children affected by it.
  • The findings indicate that several factors, including genetic and acquired conditions, can impact glucose reabsorption in the kidneys, necessitating the exclusion of diabetes mellitus and other hyperglycemia-related conditions before making a diagnosis.
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  • This study investigates the genetic causes of short stature (SS) in a unique group of children from consanguineous families in Sulaimani, Iraq, aiming to enhance understanding of SS genetics and inspire future genetic testing methods for similar populations.
  • Out of 64 eligible children with SS, genetic testing revealed a cause in 31 participants (61%), pinpointing pathogenic variants in various genes linked to growth regulation and other biological processes.
  • The findings suggest that a customized genetic testing approach is necessary to improve diagnosis rates in SS cases within consanguineous groups, as existing gene panels only identify causes in a limited percentage of cases.
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Multisystem inflammatory syndrome in children (MIS-C) is a rare condition following SARS-CoV-2 infection associated with intestinal manifestations. Genetic predisposition, including inborn errors of the OAS-RNAseL pathway, has been reported. We sequenced 154 MIS-C patients and utilized a novel statistical framework of gene burden analysis, "burdenMC," which identified an enrichment for rare predicted-deleterious variants in BTNL8 (OR = 4.

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• For children with growth deficiency, once-weekly injections were less of a burden than once-daily injections. • The safety of weekly was similar to that of daily . • Compared with daily injections, children with growth deficiency may be less likely to miss weekly injections.

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Because the causes of combined pituitary hormone deficiency (CPHD) are complex, the etiology of congenital CPHD remains unknown in most cases. The aim of the study was to identify the genetic etiology of CPHD in a well-defined single-center cohort. In total, 34 children (12 girls) with congenital CPHD (growth hormone (GH) deficiency and impaired secretion of at least one other pituitary hormone) treated with GH in our center were enrolled in the study.

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Article Synopsis
  • * 34 children with FTS were analyzed, revealing that about one-third had identifiable genetic causes, including specific karyotypes and gene variations.
  • * The findings suggest that genetic testing is essential for all children with FTS to uncover potential monogenic or cytogenetic issues, even if they don't show obvious physical signs.
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Aims/hypothesis: Monogenic diabetes is estimated to account for 1-6% of paediatric diabetes cases in primarily non-consanguineous populations, while the incidence and genetic spectrum in consanguineous regions are insufficiently defined. In this single-centre study we aimed to evaluate diabetes subtypes, obtain the consanguinity rate and study the genetic background of individuals with syndromic and neonatal diabetes in a population with a high rate of consanguinity.

Methods: Data collection was carried out cross-sectionally in November 2021 at the paediatric diabetic clinic, Dr Jamal Ahmad Rashed Hospital, in Sulaimani, Kurdistan, Iraq.

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Article Synopsis
  • - The SALL4 gene is crucial for early embryonic development and its mutations can lead to several syndromes, including Duane-radial ray syndrome and Holt-Oram syndrome, as seen in a family with a pathogenic variant causing radial hypoplasia and kidney dystopia across generations.
  • - The male proband, born small for gestational age, exhibited significant physical anomalies such as bilateral radial ray malformation and pelvic kidney dystopia, while lacking other major defects associated with SALL4 mutations.
  • - At age 3.9, the proband was evaluated for short stature, revealing low growth hormone levels and ultimately starting growth hormone therapy at age 6.5, which resulted in anticipated catch-up growth. *
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Familial short stature (FSS) describes vertically transmitted growth disorders. Traditionally, polygenic inheritance is presumed, but monogenic inheritance seems to occur more frequently than expected. Clinical predictors of monogenic FSS have not been elucidated.

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Background: The thalidomide disaster resulted in tremendous congenital malformations in more than 10,000 children in the late 1950s and early 1960s.

Summary: Although numerous putative mechanisms were proposed to explain thalidomide teratogenicity, it was confirmed only recently that thalidomide, rather its derivative 5-hydroxythalidomide (5HT) in a complex with the cereblon protein, interferes with early embryonic transcriptional regulation. 5HT induces selective degradation of SALL4, a principal transcriptional factor of early embryogenesis.

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Introduction: Among children born small for gestational age, 10-15% fail to catch up and remain short (SGA-SS). The underlying mechanisms are mostly unknown. We aimed to decipher genetic aetiologies of SGA-SS within a large single-centre cohort.

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Introduction: The growth hormone deficiency (GHD) diagnosis is controversial especially due to low specificity of growth hormone (GH) stimulation tests. It is therefore believed that children diagnosed with GHD form a heterogeneous group with growth disorder frequently independent on GH function. No study evaluating the complex etiology of growth failure in children with diagnosed GHD has been performed thus far.

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Article Synopsis
  • Somatrogon is a long-acting growth hormone treatment designed for children with growth hormone deficiency, administered once a week compared to a daily option (Somatropin).
  • The study compared the treatment burden felt by patients and caregivers during 12-week periods of each injection regimen, using standardized questionnaires to measure overall life interference.
  • Results showed that once-weekly somatrogon significantly reduced treatment burden (lower life interference scores) and was associated with greater convenience and satisfaction than the daily somatropin injections.
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The worldwide outbreak of the novel 2019 coronavirus disease (COVID-19) has led to recognition of a new immunopathological condition: paediatric inflammatory multisystem syndrome (PIMS-TS). The Czech Republic (CZ) suffered from one of the highest incidences of individuals who tested positive during pandemic waves. The aim of this study was to analyse epidemiological, clinical, and laboratory characteristics of all cases of paediatric inflammatory multisystem syndrome (PIMS-TS) in the Czech Republic (CZ) and their predictors of severe course.

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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.

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Aims: Correct genetic diagnosis of maturity-onset diabetes of the young (MODY) is beneficial for person's diabetes management compared to no genetic testing. Aim of the present study was a search for optimal time- and cost-saving strategies by comparing two approaches of genetic testing of participants with clinical suspicion of MODY.

Methods: A total of 121 consecutive probands referred for suspicion of MODY (Group A) were screened using targeted NGS (tNGS), while the other 112 consecutive probands (Group B) underwent a single gene test based on phenotype, and in cases of negative findings, tNGS was conducted.

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Aim: To date, there is a lack of international guidelines regarding the management of the endocrine features of individuals with Noonan syndrome (NS). The aim was to develop a clinical practice survey to gather information on current treatment and management of these patients across Europe.

Materials And Methods: A group of 10 experts from three clinical specialities involved in the management of NS patients (clinical geneticists, paediatric endocrinologists, and paediatric cardiologists) developed a 60-question clinical practice survey.

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