BACKGROUND:Congenital anomalies of the knee are a spectrum of rare disorders with wide clinical and genetic variability, which are mainly due to the complex processes underlying knee development. Despite progresses in understanding pathomechanisms and associated genes, many patients remain undiagnosed. OBJECTIVE:To uncover the genetic bases of a congenital patellar dislocation affecting multiple family members with variable severity. METHODS:We performed ES in the proband and his father, both showing bilateral patellar dislocation, his sister with a milder similar condition, and his unaffected mother. Sanger sequencing was then performed in the proband's brother and paternal aunt, both affected as well. RESULTS:ES and Sanger sequencing identified the presence of the novel heterozygous frameshift mutation c.735delT in the TBX4 gene in all affected family members. TBX4 is associated with autosomal dominant ischio-coxo-podo-patellar syndrome with/without pulmonary arterial hypertension (ICPPS, #147891), reaching a diagnosis in the family. Intrafamilial clinical heterogeneity suggests that other factors might be involved, such as additional variants in TBX4 or in other modifier genes. Interestingly, we identified three additional variants in the TBX4 gene in the proband only, whose phenotype is more severe. Despite being classified as benign, one of these variants is predicted to disrupt a splicing protein binding site, and may therefore affect TBX4 alternative splicing, accounting for the more severe phenotype of the proband. CONCLUSION:We expand and further delineate the genotypic and phenotypic spectrum of ICPPS. Further studies are necessary to shed light on the potential effect of this variant and on the variable phenotypic expressivity of TBX4-related phenotypes.
Acetoacetyl-CoA thiolase deficiency, also known as Beta-ketothiolase deficiency (BKTD), is an autosomal recessive organic aciduria included in the Italian newborn screening (NBS) panel. It is caused by mutations in the ACAT1 gene, which encodes the mitochondrial acetyl-CoA acetyltransferase. Its deficiency impairs the degradation of isoleucine and acetoacetyl-CoA, leading to the accumulation of toxic metabolites. We describe three cases of BKTD. The first newborn showed increase in C5:1, C4DC/C5OH, C3DC/C4OH in the NBS. Urinary organic acids (uOAs) revealed marked excretion of 2-methyl-3-hydroxybutyrate. Tiglylglycine was absent. Genetic testing identified the compound heterozygosity for two pathogenic ACAT1 variants. The second patient showed increased levels of C5:1, C4DC/C5OH, C3DC/C4OH in the NBS. uOAs revealed 2-methyl-3-hydroxybutyrate and tiglylglycine. A homozygous VUS in ACAT1 was identified. The third case showed elevation of C4DC/C5OH, C3DC/C4OH in the NBS, with a slight increase in C5:1. uOAs showed 2-methyl-3-hydroxybutyrate and tiglylglycine. A homozygous missense VUS was identified in the ACAT1 gene. BKTD exhibited variable NBS biochemical phenotypes across the three cases. While C5OH and C5:1, the primary markers, were not consistently elevated in all our cases, C4OH strongly increased in all three. Our findings support the use of C4OH in a combined marker strategy to improve BKTD NBS.
Over the past 60 years, preventative public health screening programs have evolved since their inception and now include newborn screening (NBS) aimed at identifying infants after birth for a number of rare, congenital, inherited diseases. Most of the conditions detected through NBS are autosomal recessive disorders or exhibit X-linked inheritance, meaning that family members of individuals with these conditions have a higher risk for being either affected or obligate heterozygotes. For example, the X-linked adrenoleukodystrophy (X-ALD) in the screening panel identifies affected newborns and asymptomatic relatives through subsequent testing. Thus, NBS becomes a gateway to family-wide prevention, through the application of reverse cascade testing (RCS). In this paper we examined the scenarios where RCS may be appropriate. Accordingly, we have identified a list of criteria assessing whether a NBS disease would benefit from RCS: (1) autosomal recessive or X-linked inheritance; (2) high carrier rates, (3) variable expressivity, (4) mild or late-onset forms; and (5) association with diagnostic delays and recent addition to the screening panel. More than one criterion usually needs to be met for a disease to benefit from RCS. We have identified a list of diseases and highlighted the potential benefits of RCS: X-ALD, Cystic Fibrosis, Sickle Cell Disease, Spinal Muscular Atrophy and Pompe disease. There are additional scenarios within NBS where disease maternal conditions (3-methylcrotonyl-CoA carboxylase deficiency and carnitine uptake deficiency) or nutritional maternal conditions (vitamin B12 deficiency) may cause a screen-positive NBS result. Whenever a maternal nutritional deficiency is a potential reason for a positive NBS, this is indicative of a non-inherited condition that may require treatment in the newborn owing to possible neurological damage and delay in normal growth in newborns with certain secondary deficiencies. For these cases RCS is recommended, as the mother's status may put her at risk for future adverse events (i.e. cardiovascular and musculoskeletal disorders, hepatic involvement, and neurodegeneration). The RCS-NBS strategy discussed in this paper offers a set of criteria against which diseases can be assessed for the potential need for RCS. Implementation of this strategy requires several considerations including educational needs, ethical issues, uptake of testing, logistics and costs for this expanded screening and counseling, and availability of appropriate specialists for ongoing management.
BACKGROUND:Newborn screening (NBS) is a preventive healthcare program aiming at identifying the inborn errors of metabolism (IEMs) in asymptomatic infants to reduce the risk of severe complications. The aim of this study was to report the first years (2016-2020) of the expanded NBS program in the Lombardy region, Italy. METHODS:Dried blood spots were collected from newborns' heels at 48-72 h after birth. FIA-MS/MS was performed to evaluate specific biochemical markers. Genetic confirmation was achieved via Sanger or NGS on newborns and reported to a clinical reference center (CRC). RESULTS:A total of 343,507 newborns were tested; 1414/343,507 resulted as positive to NBS and were reported to the CRC. A total of 209 newborns were diagnosed with IEMs: 206 infants received a diagnosis of IEM through NBS, confirmed by genetic analysis; three neonates were not positive to NBS but were subsequentially diagnosed with IEMs. A total of 1208/343,507 were false positive cases. Twenty-seven types of IEMs were diagnosed in 209 patients: 111 newborns were affected by aminoacidemias, 11 by urea cycle disorders, 27 by organic acidemias, 34 by fatty acid oxidation disorders, and 26 by secondary conditions. CONCLUSIONS:We report here for the first time the IEM incidence and distribution in the Lombardy region in the first five years of NBS.
Biomedical research during spaceflight and simulation studies reveals significant changes in biochemical and cellular pathways relevant to understanding diseases on Earth. While adult health has been the historical focus of aerospace medicine, applications for children’s health remain unexplored and are becoming more paramount as civilian access to space increases. We discuss biological and physiological changes in spaceflight that may be relevant to pediatric diseases. We also explore nutritional approaches for pediatric conditions, which may also benefit astronaut health.
Background: Since the initial description of glucose transporter -1 deficiency syndrome (Glut1-DS) the phenotype of the condition has expanded, even leading to the recognition of atypical manifestations. We report on eight patients with Glut1-DS who experienced at least one episode of acute focal neurological deficits. Methods: We conducted a retrospective analysis, collecting clinical, electrophysiological, neuroradiological, and genetic information. We focused in particular on three well-documented cases. Results: Among 42 patients with Glut1-DS, eight individuals aged between six and 38 years presented with an acute onset of neurological disturbances: dysarthria/aphasia, oral dyskinesia, swallowing difficulties, paresthesia, facial palsy, hemi/monoplegia, vomiting, headache, and behavioral disturbances. When performed, magnetic resonance imaging (MRI) revealed signs of venous congestion and hypoperfusion and electroencephalography showed focal contralateral slowing. Deficits were transient in all patients but one. Four patients (50%) were on a ketogenic diet (KD), and two of these patients had lower than usual ketonemia levels during the episode. In two patients, MRI demonstrated the presence of an ischemic brain lesion. Conclusions: In Glut1-DS, stroke-like episodes are a recurrent manifestation, particularly during early adulthood, and they were reported in 19% of the patients in our cohort. Stroke mimics should be considered a key feature of Glut1-DS, as other paroxysmal disorders. It remains to be established whether a KD can prevent the recurrence of episodes and, if so, at what level of ketosis. Further observations are needed to confirm the correlation between Glut1-DS and ischemic stroke. (c) 2024 The Author(s). Published by Elsevier Inc. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
Leukodystrophies are a class of rare heterogeneous disorders which affect the white matter of the brain, ultimately leading to a disruption in brain development and a damaging effect on cognitive, motor and social-communicative development. These disorders present a great clinical heterogeneity, along with a phenotypic overlap and this could be partially due to contributions from environmental stimuli. It is in this context that there is a great need to investigate what other factors may contribute to both disease insurgence and phenotypical heterogeneity, and novel evidence are raising the attention toward the study of epigenetics and transcription mechanisms that can influence the disease phenotype beyond genetics. Modulation in the epigenetics machinery including histone modifications, DNA methylation and non-coding RNAs dysregulation, could be crucial players in the development of these disorders, and moreover an aberrant RNA maturation process has been linked to leukodystrophies. Here, we provide an overview of these mechanisms hoping to supply a closer step toward the analysis of leukodystrophies not only as genetically determined but also with an added level of complexity where epigenetic dysregulation is of key relevance. This article is categorized under: Regulatory RNAs/RNAi/Riboswitches > Regulatory RNA RNA in Disease and Development > RNA in Disease RNA in Disease and Development > RNA in Development.
Moebius syndrome (MBS) is a rare congenital disorder characterized by non-progressive facial palsy and ocular abduction paralysis. Most cases are sporadic, but also rare familial cases with autosomal dominant transmission and incomplete penetrance/variable expressivity have been described. The genetic etiology of MBS is still unclear: de novo pathogenic variants in REV3L and PLXND1 are reported in only a minority of cases, suggesting the involvement of additional causative genes. With the aim to uncover the molecular causative defect and identify a potential genetic basis of this condition, we performed trio-WES on a cohort of 37 MBS and MBS-like patients. No de novo variants emerged in REV3L and PLXND1. We then proceeded with a cohort analysis to identify possible common causative genes among all patients and a trio-based analysis using an in silico panel of candidate genes. However, identified variants emerging from both approaches were considered unlikely to be causative of MBS, mainly due to the lack of clinical overlap. In conclusion, despite this large cohort, WES failed to identify mutations possibly associated with MBS, further supporting the heterogeneity of this syndrome, and suggesting the need for integrated omics approaches to identify the molecular causes underlying MBS development.
Each year thousands of babies are born with rare genetic disorders not identified by current NBS panels, due to programs which are not yet optimal. Next-generation sequencing technologies have the potential to overcome many NBS drawbacks and provide large amounts of molecular data, broadening the number of diseases investigated. Here, we design and set up an NGS-based approach to evaluate the feasibility of NGS from dried blood spot starting from 34 DBSs. After assessing gDNA yield and integrity, libraries were performed using three target enrichment approaches, sequenced on NS500 platform, and analyzed on commercial platform. Specifically, we focus on virtual gene panels related to highly actionable neonatal/pediatric disorders. WES show that amount and quality of DBS-extracted gDNA are suitable for high-throughput sequencing. We obtain 500–1500 ng for each specimen, 1.7–1.8 260/280 wavelength, and DIN of 7 resulting DNA integrity, on par with traditional venous blood collection. A high read depth with 94.3% coverage uniformity is achieved for all samples. Data results on mean coverage are comparable among the different workflows tested and demonstrate that DBS from newborn collected at birth is a suitable material for the developing of gNBS programs.
The adipose tissue is a crucial energy reservoir that can undergo significant changes during aging,impacting the pathogenesis of metabolic disorders,including obesity.1 Obesity affects individuals of all ages,with different impli-cations for each stage of life.It is thought to be a state of accelerated aging,prompting the introduction of the term"adipaging",for which obesity and aging share key biological hallmarks strictly related to a dysfunctional adipose tissue.