We have established Noonan syndrome (NS)-derived induced pluripotent stem cell (iPSC) lines derived from peripheral blood mononuclear cells (PBMCs) of a family cohort carrying the heterozygous PTPN11 ...c.188 A > G (p.Y63C) mutation. The new iPSC lines were validated by confirming the normal karyotype and targeted mutation, the pluripotent gene expression, and the differentiation capacity into three germ layers.
Context:
Adenotonsillar tissue hypertrophy and obstructive sleep apnea have been reported during short-term GH treatment in children with Prader-Willi syndrome (PWS).
Objective:
We conducted an ...observational study to evaluate the effects of long-term GH therapy on sleep-disordered breathing and adenotonsillar hypertrophy in children with PWS.
Design:
This was a longitudinal observational study.
Patients and Methods:
We evaluated 75 children with genetically confirmed PWS, of whom 50 fulfilled the criteria and were admitted to our study. The patients were evaluated before treatment (t0), after 6 weeks (t1), after 6 months (t2), after 12 months (t3), and yearly (t4–t6) thereafter, for up to 4 years of GH therapy. The central apnea index, obstructive apnea hypopnea index (OAHI), respiratory disturbance index, and minimal blood oxygen saturation were evaluated overnight using polysomnography. We evaluated the adenotonsillar size using a flexible fiberoptic endoscope.
Results:
The percentage of patients with an OAHI of >1 increased from 3 to 22, 36, and 38 at t1, t4, and t6, respectively (χ2 = 12.2; P < .05). We observed a decrease in the respiratory disturbance index from 1.4 (t0) to 0.8 (t3) (P < .05) and the central apnea index from 1.2 (t0) to 0.1 (t4) (P < .0001). We had to temporarily suspend treatment for 3 patients at t1, t4, and t5 because of severe obstructive sleep apnea. The percentage of patients with severe adenotonsillar hypertrophy was significantly higher at t4 and t5 than at t0. The OAHI directly correlated with the adenoid size (adjusted for age) (P < .01) but not with the tonsil size and IGF-1 levels.
Conclusion:
Long-term GH treatment in patients with PWS is safe; however, we recommend annual polysomnography and adenotonsillar evaluation.
In the last few years, trio-Whole Exome Sequencing (WES) analysis has revolutionized the diagnostic process for patients with rare genetic syndromes, demonstrating its potential even in non-specific ...clinical pictures and in atypical presentations of known diseases. Multiple disorders in a single patient have been estimated to occur in approximately 2–7.5% of diagnosed cases, with higher frequency in consanguineous families. Here, we report the clinical and molecular characterisation of eight illustrative patients for whom trio-WES allowed for identifing more than one genetic condition. Double homozygosity represented the causal mechanism in only half of them, whereas the other half showed peculiar multilocus combinations. The paper takes into consideration difficulties and learned lessons from our experience and therefore supports the powerful role of wide analyses for ascertaining multiple genetic diseases in complex patients, especially when a clinical suspicion could account for the majority of clinical signs. It finally makes clear how a patient’s “deep phenotyping” might not be sufficient to suggest the presence of multiple genetic diagnoses but remains essential to validate an unexpected multilocus result from genetic tests.
Bardet-Biedl syndrome (BBS) is a rare inherited multisystemic disorder with autosomal recessive or complex digenic triallelic inheritance. There is currently no treatment for BBS, but some ...morbidities can be managed. Accurate molecular diagnosis is often crucial for the definition of appropriate patient management and for the development of a potential personalized therapy.
We developed a next-generation-sequencing (NGS) protocol for the screening of the 18 most frequently mutated genes to define the genotype and clarify the mutation spectrum of a cohort of 20 BBS Italian patients.
We defined the causative variants in 60% of patients; four of those are novel. 33% of patients also harboured variants in additional gene/s, suggesting possible oligogenic inheritance. To explore the function of different genes, we looked for correlations between genotype and phenotype in our cohort. Hypogonadism was more frequently detected in patients with variants in BBSome proteins, while renal abnormalities in patients with variations in BBSome chaperonin genes.
NGS is a powerful tool that can help understanding BBS patients' phenotype through the identification of mutations that could explain differences in phenotype severity and could provide insights for the development of targeted therapy. Furthermore, our results support the existence of additional BBS loci yet to be identified.
Inactivating
mutations causing Sotos syndrome have been previously associated with a specific genome-wide DNA methylation (DNAm) pattern. Sotos syndrome is characterized by phenotypic overlap with ...other overgrowth syndromes, and a definite diagnosis might not be easily reached due to the high prevalence of variants of unknown significance (VoUS) that are identified in patients with a suggestive phenotype.
we performed microarray DNAm profiling in a set of 11 individuals with a clinical suspicion of Sotos syndrome and carrying an
VoUS or previously unreported variants to solve uncertainty in defining pathogenicity of the observed variants. The impact of the training cohort size on sensitivity and prediction confidence of the classifier was assessed.
The Sotos syndrome-specific DNAm signature was validated in six individuals with a clinical diagnosis of Sotos syndrome and carrying
pathogenic
variants. Applying this approach to the remaining 11 individuals with
variants, we succeeded in confirming pathogenicity in eight subjects and excluding the diagnosis of Sotos syndrome in three. The sensitivity and prediction confidence of the classifier based on the different sizes of the training sets did not show substantial differences, though the overall performance was improved by using a data balancing strategy.
The present approach solved uncertainty in cases with
VoUS, further demonstrating the clinical utility of DNAm profiling.
During COVID-19 pandemic lockdown, reports of evaluations for suspected precocious puberty significantly raised. We aimed to assess the increase of precocious puberty in patients referred to ...Pediatric Endocrinology Units of Brescia (Italy), to determine clinical characteristics of patients undergoing a GnRH stimulation test before and during lockdown and evaluate the role of environmental factors in pubertal development.
Clinical and biochemical data of patients undergoing GnRH stimulation test were collected and stratified in two groups: March 2019 - February 2020 (Period 1) and March 2020 - February 2021 (Period 2).
A total number of 391 evaluations for suspected precocious puberty were identified in the two study periods: 183 (46.8%) first visits during Period 1, and 208 (53.2%) in Period 2. Sixty-one patients underwent a GnRH stimulation test (4.1% of first consultations) before the SARS-CoV2 pandemic, and 93 children (8.7%) after the lockdown. Thirty-four new diagnoses of central precocious puberty were registered during Period 1 (2.3%), vs. 45 new cases (4.2%) in Period 2. During lockdown patients evaluated for suspected precocious puberty underwent a stimulation test at younger age than those evaluated before pandemic (median age of 8.2 years vs. 8.4, p=0.04). In Period 2, children showed a median bone age advancement of 0.61 years vs. 1.06 of Period 1 (p=0.03).
During the COVID-19 pandemic, we observed an increased proportion of consultations for suspected precocious puberty. These children showed lower bone age advancement than observed in pre-lockdown suggesting the influence of pandemic-related lifestyle changes on pubertal development.
Purpose
Selective IgA deficiency (SIgAD) is the most common humoral primary immunodeficiency. Long-term follow-up data in large cohort of pediatric patients are scarce.
Methods
We report on a ...single-center cohort of 184 pediatric patients affected with selective IgA deficiency and describe the characteristics at diagnosis and during follow-up.
Results
Respiratory infections were the most common clinical finding leading to the initial diagnosis (62%). Positive family history for antibody deficiencies (selective IgA deficiency, common variable immunodeficiency) led to SIgAD diagnosis in 16% of cases. During follow-up, while the incidence of respiratory infections was not particularly high, gastrointestinal symptoms were reported in 27% of patients. Allergic manifestations were found in 23% at diagnosis and an additional 16% of patients during follow-up, leading to a prevalence of atopy of 39% among SIgAD patients. Autoimmune manifestations, excluding celiac disease, were found in 9% of affected patients during follow-up. Celiac disease was found in a high prevalence (14%). Increase of serum IgA levels to partial deficiency (9%) and normal serum levels for age (4%) was observed during follow-up. A small percentage of patients (2%) progressed to common variable immunodeficiency (CVID).
Conclusions
In conclusion, this is the first study to describe a large single-center pediatric cohort of patients affected with SIgAD, revealing that overall most patients do well with regard to infections. Many develop CD, at a rate much higher than the general population. A few normalize their IgA levels. A few progress to CVID. Thus, careful follow-up is suggested to diagnose and treat potential complications earlier for avoiding potential morbidities.
ABSTRACT
Kabuki syndrome (KS) is a multiple congenital anomalies syndrome characterized by characteristic facial features and varying degrees of mental retardation, caused by mutations in KMT2D/MLL2 ...and KDM6A/UTX genes. In this study, we performed a mutational screening on 303 Kabuki patients by direct sequencing, MLPA, and quantitative PCR identifying 133 KMT2D, 62 never described before, and four KDM6A mutations, three of them are novel. We found that a number of KMT2D truncating mutations result in mRNA degradation through the nonsense‐mediated mRNA decay, contributing to protein haploinsufficiency. Furthermore, we demonstrated that the reduction of KMT2D protein level in patients’ lymphoblastoid and skin fibroblast cell lines carrying KMT2D‐truncating mutations affects the expression levels of known KMT2D target genes. Finally, we hypothesized that the KS patients may benefit from a readthrough therapy to restore physiological levels of KMT2D and KDM6A proteins. To assess this, we performed a proof‐of‐principle study on 14 KMT2D and two KDM6A nonsense mutations using specific compounds that mediate translational readthrough and thereby stimulate the re‐expression of full‐length functional proteins. Our experimental data showed that both KMT2D and KDM6A nonsense mutations displayed high levels of readthrough in response to gentamicin treatment, paving the way to further studies aimed at eventually treating some Kabuki patients with readthrough inducers.
In this report, we have expanded the spectrum of mutations of KMT2D and KDM6A genes by analysing our cohort of 303 Kabuki patients by direct sequencing, MLPA and quantitative PCR. Based on KMT2D biological role, we designed functional studies that highlighted the haploinsufficiency of KMT2D as one of the mechanisms underlying the pathogenesis of the disease. Moreover, we provided the first preliminary proof‐of‐concept that occurring nonsense mutations in KMT2D and KDM6A can be effectively suppressed and the functional endogenous protein level and biological activity of KMT2D and KDM6A proteins restored.
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