Absent or hypoplastic nasal bone: What to tell the prospective parents?

BACKGROUND: Absent or hypoplastic nasal bone (AHNB) on first or second-trimester ultrasonography (USG) is an important soft marker of Down syndrome. However, due to its varied incidence in euploid and aneuploid fetuses, there is always a dilemma of whether to go for invasive fetal testing for isolated AHNB. This study aims to assess outcomes specifically within the context of Indian ethnicity women. MATERIALS AND METHODS: This was a prospective observational study. All patients who reported with AHNB in the first- or second-trimester USG were included. Genetic counseling was done, and noninvasive and invasive testing was offered. Chromosomal anomalies were meticulously recorded, and pregnancy was monitored. RESULTS: The incidence of AHNB in our study was 1.16% (47/4051). Out of 47 women with AHNB, the isolated condition was seen in 32 (0.78%) cases, while AHNB with structural anomalies was seen in nine cases (0.22%). Thirty-nine women opted for invasive testing. Six out of 47 had aneuploidy (12.7%), while two euploid cases (4.25%) developed nonimmune hydrops. The prevalence of Down syndrome in fetuses with AHNB was 8.5% (4/47) and 0.42% (17/4004) in fetuses with nasal bone present. This difference was statistically significant (p = .001). CONCLUSION: The results indicate that isolated AHNB cases should be followed by a comprehensive anomaly scan rather than immediately recommending invasive testing. However, invasive testing is required when AHNB is associated with other soft markers or abnormalities. As chromosomal microarray is more sensitive than standard karyotype in detecting chromosomal aberrations, it should be chosen over karyotype.

Cardiac Complications in Trisomy 21 Patients in a Secondary Hospital: A Descriptive Study.

This retrospective study addresses the intersection of Down syndrome (DS) and congenital heart defects (CHD), including the prevalence and characteristics of CHD in trisomy 21 patients at a secondary hospital in the Eastern Province of Saudi Arabia. The study investigated the electronic medical records retrieved from the Qatif Central Hospital database, specifically targeting individuals diagnosed with DS (identified by the International Classification of Diseases, Tenth Revision (ICD-10) code Q90.9) between March 2012 and March 2022. The primary aim was to detect cardiac anomalies diagnosed via echocardiography performed at the hospital, along with subsequent follow-up assessments and documented patient outcomes. Among the 161 patients reviewed, the study revealed a significant prevalence of diagnosed heart defects through echocardiograms, constituting approximately 72.7%. Notably, patent ductus arteriosus was the most common condition, found in 29.81% of cases, followed by atrial septal defect (27.95%) and atrioventricular septal defect (17.39%). Among the study participants, 22.98% required surgical intervention. Unfortunately, mortality impacted 32.3% of individuals, while the majority (60.87%) remained alive. In addition, a small percentage (6.83%) discontinued follow-up within our center. This study contributes significant data on cardiac anomalies in DS patients in Saudi Arabia, highlighting a high prevalence of CHD with specific patterns of anomalies. The need for early diagnosis, timely surgical intervention, and ongoing management is evident. These findings provide a foundation for improving clinical practices and shaping public health policies tailored to the needs of this population in Saudi Arabia and similar regions.

The Role of Tau Pathology in Alzheimer's Disease and Down Syndrome.

Background: Individuals with Down syndrome (DS) exhibit an almost complete penetrance of Alzheimer's disease (AD) pathology but are underrepresented in clinical trials for AD. The Tau protein is associated with microtubule function in the neuron and is crucial for normal axonal transport. In several different neurodegenerative disorders, Tau misfolding leads to hyper-phosphorylation of Tau (p-Tau), which may seed pathology to bystander cells and spread. This review is focused on current findings regarding p-Tau and its potential to seed pathology as a "prion-like" spreader. It also considers the consequences of p-Tau pathology leading to AD, particularly in individuals with Down syndrome. Methods: Scopus (SC) and PubMed (PM) were searched in English using keywords "tau AND seeding AND brain AND down syndrome". A total of 558 SC or 529 PM potentially relevant articles were identified, of which only six SC or three PM articles mentioned Down syndrome. This review was built upon the literature and the recent findings of our group and others. Results: Misfolded p-Tau isoforms are seeding competent and may be responsible for spreading AD pathology. Conclusions: This review demonstrates recent work focused on understanding the role of neurofibrillary tangles and monomeric/oligomeric Tau in the prion-like spreading of Tau pathology in the human brain.

Rapidly Progressive Contralateral Internal Carotid Artery Stenosis After COVID-19 Infection in a Down Syndrome Patient With Unilateral Moyamoya Arteriopathy.

Moyamoya arteriopathy is a condition where chronic, progressive stenosis of large intracranial arteries, primarily of the anterior circulation, results in ischemia and the growth of small, abnormal collateral vessels. There is increasing evidence that infectious pathologies, such as COVID-19, may serve as a sort of trigger, or "second hit," for the development of moyamoya arteriopathy. In this article, we present the case of a 13-year-old female with Down syndrome and unilateral moyamoya arteriopathy who developed contralateral internal carotid artery (ICA) dissection and thrombus in the setting of a positive COVID-19 test and subsequently developed rapidly progressive contralateral ICA and bilateral anterior cerebral artery (ACA) moyamoya-like stenosis. The rapidly progressive contralateral ICA and bilateral ACA moyamoya-like stenosis are likely multifactorial in nature. The contralateral ICA may have had a predisposition for injury and stenosis due to the preexisting moyamoya arteriopathy, making stenosis more likely after COVID-19-induced vascular inflammation and injury as well as after a possible thrombectomy-associated injury. Based on this presentation, patients with moyamoya arteriopathy may be at risk for rapid progression of their moyamoya pathology when exposed to catalysts, including infection, such as COVID-19, and vascular injury, such as thrombectomy-induced injury. In these circumstances, high suspicion and close monitoring are essential for addressing ischemia related to the stenosis before permanent injury.

Competing Endogenous RNAs Crosstalk in Hippocampus: A Potential Mechanism for Neuronal Developing Defects in Down Syndrome.

Down syndrome (DS) is the most example of aneuploidy, resulting from an additional copy of all or part of chromosome 21. Competing endogenous RNAs (ceRNAs) play important roles in neuronal development and neurological defects. This study aimed to identify hub genes and synergistic crosstalk among ceRNAs in the DS fetal hippocampus as potential targets for the treatment of DS-related neurodegenerative diseases. We profiled differentially expressed long non-coding RNAs (DElncRNAs), differentially expressed circular RNAs (DEcircRNAs), differentially expressed microRNAs (DEmiRNAs), and differentially expressed messenger RNAs (DEmRNAs) in hippocampal samples from patients with or without DS. Functional enrichment analysis and gene set enrichment analysis were performed, and chromosome 21-related ceRNA and protein-protein interaction networks were constructed. Additionally, the correlations between lncRNA-mRNA and miRNA-mRNA expression in the samples and HEK293T cells were validated. Our finding of changes in the expression of some key genes and ncRNAs on chromosome 21 in DS might not fully conform to the gene dosage hypothesis. Moreover, we found that four lncRNAs (MIR99AHG, PLCB4, SNHG14, GIGYF2) and one circRNA (hsa_circ_0061697) may competitively bind with three miRNAs (hsa-miR-548b-5p, miR-730-5p, and hsa-miR-548i) and subsequently regulate five mRNAs (beta-1,3-galactosyltransferase 5 [B3GALT5], helicase lymphoid-specific [HELLS], thrombospondin-2 [THBS2], glycinamide ribonucleotide transformylase [GART], clathrin heavy chain like 1 [CLTCL1]). These RNAs, whether located on chromosome 21 or not, interact with each other and might activate the PI3K/Akt/mTOR and Wnt signaling pathways, which are involved in autophagosome formation and tau hyperphosphorylation, possibly leading to adverse consequences of trisomy 21. These findings provide researchers with a better understanding of the fundamental molecular mechanisms underlying DS-related progressive defects in neuronal development.

Pragmatic competence in people with dual diagnosis: down syndrome and autism spectrum disorder.

BACKGROUND: Pragmatics is an area that can be affected in a wide variety of disorders. In this sense, Syndromic Autism is defined as a disorder in which a causal link is established between an associated syndrome and Autism Spectrum Disorder (ASD). Likewise, Down Syndrome (DS) is one of the main genetically based syndromes in which ASD is described as one of its possible manifestations. In this direction, people with DS are described as social beings whereas in ASD there seems to be a specific alteration of this domain. METHODS: In this study, pragmatic performance was analysed in a sample of 72 participants, where comparisons were made between the scores obtained by children with ASD (n = 24), with DS (n = 24) and with DS + ASD (n = 24). RESULTS: The Social Communication Questionnaire (SCQ), the Block Objective and Criterial Language Battery (BLOC-SR) and the Neuropsychology subtest (NEPSY-II) aimed at Theory of Mind (ToM) identified significant differences between the groups. However, two-to-two comparisons reported no significant differences between DS and DS + ASD. CONCLUSIONS: Although several studies report differences between the three proposed groups, our data seem to suggest that ASD symptomatology in DS is associated with Intellectual Developmental Disorder (IDD). However, the lack of solid scientific evidence regarding comorbid diagnosis makes further research along these lines indispensable. TRIAL REGISTRATION: This study was approved by the Ethics Committee for Social Research at UCLM with reference CEIS-704,511-L8M4.

First clinical evidence that trimethylsulfonium can serve as a biomarker for the production of the signaling molecule hydrogen sulfide.

BACKGROUND: Hydrogen sulfide (H2S) is established as the third gaseous signaling molecule and is known to be overproduced in down syndrome (DS) due to the extra copy of the CBS gene on chromosome 21, which has been suggested to contribute to the clinical manifestation of this condition. We recently discovered trimethylsulfonium (TMS) in human urine and highlighted its potential as a selective methylation metabolite of endogenously produced H2S, but the clinical utility of this novel metabolite has not been previously investigated. We hypothesize that the elevation of H2S production in DS would be reflected by an elevation in the methylation product TMS. METHODS: To test this hypothesis, a case-control study was performed and the urinary levels of TMS were found to be higher in the DS group (geo. mean 4.5 nM, 95 % CI 2.4-3.9) than in the control (N) group (3.1 nM, 3.5-6.0), p-value 0.01, whereas the commonly used biomarker of hydrogen sulfide, thiosulfate, failed to reflect this alteration in H2S production (15 µM (N) vs. 13 µM (DS), p-value 0.24. RESULTS: The observed association is in line with the proposed hypothesis and provides first clinical evidence of the utility of TMS as a novel and more sensitive biomarker for the endogenous production of the third gaseous signaling molecule than the conventionally used biomarker thiosulfate, which is heavily dependent on bacterial hydrogen sulfide production. CONCLUSION: This work shows that TMS must be explored in clinical conditions where altered metabolism of hydrogen sulfide is implicated.

Takotsubo cardiomyopathy secondary to electroconvulsive therapy in a young adult with Down syndrome regression disorder.

We report the case of an 18-year-old woman with Down syndrome (DS) who developed Takotsubo cardiomyopathy (TSC) immediately after the administration of electroconvulsive therapy (ECT), a treatment prescribed for Down syndrome regression disorder resistant to oral psychotropic drugs. TSC is a nonischemic cardiomyopathy related to psychological or physical stress, which has been described as a rare complication of ECT (Kinoshita et al., 2023, Journal of Electroconvulsive Therapy, 39, 185-192). The clinical description of the case is accompanied by a discussion of the peculiarities of the autonomic nervous system in DS.

Pathways linking pulse pressure to dementia in adults with Down syndrome.

Individuals with Down syndrome (DS) are less likely to have hypertension than neurotypical adults. However, whether blood pressure measures are associated with brain health and clinical outcomes in this population has not been studied in detail. Here, we assessed whether pulse pressure is associated with markers of cerebrovascular disease, entorhinal cortical atrophy, and diagnosis of dementia in adults with DS. Participants with DS from the Biomarkers of Alzheimer's Disease in Adults with Down Syndrome study (ADDS; n=195, age=50.6±7.2 years, 44% women, 18% diagnosed with dementia) were included. Higher pulse pressure was associated with greater global, parietal, and occipital WMH volume. Pulse pressure was not related to enlarged PVS, microbleeds, infarcts, entorhinal cortical thickness, or dementia diagnosis. However, in a serial mediation model, we found that pulse pressure was indirectly related to dementia diagnosis through parieto-occipital WMH and, subsequently through entorhinal cortical thickness. Higher pulse pressure may be a risk factor for dementia in people with DS by promoting cerebrovascular disease, which in turn affects neurodegeneration. Pulse pressure is an important determinant of brain health and clinical outcomes in individuals with Down syndrome despite the low likelihood of frank hypertension.

Sex Differences in Brain Disorders.

A remarkable feature of the brain is its sexual dimorphism. Sexual dimorphism in brain structure and function is associated with clinical implications documented previously in healthy individuals but also in those who suffer from various brain disorders. Sex-based differences concerning some features such as the risk, prevalence, age of onset, and symptomatology have been confirmed in a range of neurological and neuropsychiatric diseases. The mechanisms responsible for the establishment of sex-based differences between men and women are not fully understood. The present paper provides up-to-date data on sex-related dissimilarities observed in brain disorders and highlights the most relevant features that differ between males and females. The topic is very important as the recognition of disparities between the sexes might allow for the identification of therapeutic targets and pharmacological approaches for intractable neurological and neuropsychiatric disorders.

Ischemic Stroke in a Seven-Year-Old Female With Down Syndrome and Newly Discovered Moyamoya Syndrome.

Moyamoya represents a rare, progressive cerebrovascular disease, characterized by a gradual stenosis of the intracranial internal carotid arteries, thereby increasing the risk of stroke. Down syndrome is known to be a predisposing factor for Moyamoya syndrome. This review discusses a distinctive case of a seven-year-old female with Down syndrome who manifested with Moyamoya syndrome, evident from acute stroke-like symptoms.

Generation of two induced pluripotent stem cell lines from patients with Down syndrome.

Down syndrome (DS) is caused by trisomy of Homo sapiens chromosome 21 (HSA21) and is by far the most common chromosomal disorder accompanied by neurodevelopmental disorders and congenital heart disease. Here, we generated two induced pluripotent stem cell (iPSC) lines from two patients with DS. These two lines exhibited normal morphology, trisomy 21 karyotype, pluripotency and differentiation capability into derivatives of three germ layers. The patient-specific iPSC lines arean invaluable resource in research to model DS-related cellular and molecular pathologies and test possible therapeutic strategies for DS.

Down-Syndrome-Related Maternal Dysbiosis Might Be Triggered by Certain Classes of Antibiotics: A New Insight into the Possible Pathomechanisms.

Down syndrome (DS) is a leading human genomic abnormality resulting from the trisomy of chromosome 21. The genomic base of the aneuploidy behind this disease is complex, and this complexity poses formidable challenges to understanding the underlying molecular basis. In the spectrum of the classic DS risk factor associations, the role of nutrients, vitamins, and, in general, the foodborne-associated background, as part of the events ultimately leading to chromosome nondisjunction, has long been recognized as a well-established clinical association. The integrity of the microbiome is a basic condition in these events, and the dysbiosis may be associated with secondary health outcomes. The possible association of DS development with maternal gut microbiota should therefore require more attention. We have hypothesized that different classes of antibiotics might promote or inhibit the proliferation of different microbial taxa; and hence, we might find associations between the use of the different classes of antibiotics and the prevalence of DS through the modification of the microbiome. As antibiotics are considered major disruptors of the microbiome, it could be hypothesized that the consumption/exposure of certain classes of antibiotics might be associated with the prevalence of DS in European countries (N = 30). By utilizing three different statistical methods, comparisons have been made between the average yearly antibiotic consumption (1997-2020) and the estimated prevalence of people living with DS for the year 2019 as a percentage of the population in European countries. We have found strong statistical correlations between the consumption of tetracycline (J01A) and the narrow-spectrum, beta-lactamase-resistant penicillin (J01CF) and the prevalence of DS.

Cleft Palate in a Newborn With Trisomy 21: A Case Report.

Trisomy 21, or Down syndrome (DS), is neonates' most common chromosomal abnormality. In addition, children born with DS have an increased risk of congenital anomalies such as congenital heart defects, gastrointestinal abnormalities, and, rarely, cleft palate. Cleft lip and palate are among the most common congenital anomalies associated with many congenital syndromes; however, Trisomy 21 is the least common congenital anomaly associated with orofacial clefts. We present a case of cleft palate, duodenal stenosis, persistent pulmonary hypertension of the newborn, patent ductus arteriosus, and atrial septal defect in a newborn with classical clinical features of Down syndrome. This report discusses the uncommon presentation of trisomy 21 and concomitant cleft palate in a neonate, including its recognition and treatment, as no standard of care treatment exists.

Financial impact of a specialized Down syndrome clinic: Implications and support for institutional support of specialty care clinics.

Individuals with Down syndrome (DS) have specific health care needs and require additional screening and surveillance for commonly associated conditions. The American Academy of Pediatrics (AAP) Committee on Genetics has provided clinical guidance in "Health Supervision for Children and Adolescents with Down Syndrome." Many DS specialty centers (DSC) have been created, in part, to help ensure adherence to these guidelines. The primary purpose of this work is to determine the financial impact of a specialized DSC. A retrospective chart review was completed for all patients seen in DSC for fiscal year 2018 (June 2018-June 2019). Charts were reviewed to ascertain the financial impact of a DSC to a healthcare system by calculating total downstream charges (using CMS Chargemaster) as a surrogate marker for financial impact. Five-hundred-seventy-four patient encounters were conducted; 99 were new patient visits. Annual charges totaled $1,399,450. The 1-5-year-old age group accounted for greater than half of all charges. The greatest proportion of charges resulted from sleep studies and other diagnostic testing (55%). DS clinics are extremely helpful in ensuring that children receive guideline-based care. Taking into account downstream revenue, specialized DSCs are also financially beneficial to the institutions with whom they are affiliated.

An asymptomatic giant AB thymoma in a patient with Down syndrome: a case report.

Background: Mediastinal mass management may represent a real challenge for all the physicians who deal with it. Mediastinum, in fact, contains different vital structures which are often involved by growing neoplasms with increasing severity. Therefore, up to 60% of the patients with mediastinal mass are symptomatic, according to the structure involved. Different neoplasms may arise essentially from all mediastinal organs, whereas thymic epithelial tumors and lymphomas represent more than 90% of mediastinal tumors. Case Description: We report the first case described of a giant asymptomatic mediastinal mass in a 43-year-old male affected by Down syndrome (DS), turned out to be a thymoma, treated exclusively and successfully with radical surgery. Despite the absence of any symptoms, the giant thymoma infiltrated the diaphragm, the pericardium, the upper lobe of the left lung together with the left phrenic nerve resulting in the compression of heart and great vessels. Conclusions: To date, this is the first description of a thymic malignancy in a patient with DS, that usually is characterized by a low-incidence of solid tumor except for germ-cells ones. Surgery has been extremely challenging, due the clinical condition of the patient together with the tumor features; nevertheless, oncological radicality criteria were completely fulfilled. After four years from surgery, the patient is alive and still disease-free, highlighting the importance of radical surgery.

Primary membranoproliferative glomerulonephritis in a child with down syndrome complicated with CVA: A case report.

Introduction: Down syndrome (DS) is a genetic disorder that affects multiple organs but glomerular lesions were reported only in case reports such as focal segmental glomerulosclerosis (FSGS), and Membranoproliferative glomerulonephritis (MPGN). Case presentation: A 14-year-old male child with DS was presented with generalized edema over three months. Laboratory tests revealed nephrotic syndrome (NS) and urinary tract infection (UTI). Renal ultrasound consisted with CKD. Kidney biopsy corresponded with MPGN. Also, all investigations for secondary underlying disorders came back negative suggesting the idiopathic form. Moreover, the status complicated with cerebrovascular accident (CVA), which has not been described in a DS- patient with glomerulonephritis. Discussion/conclusion: The relationship between DS and the incidence of glomerulonephritis is unclear. we suggest regular monitoring of renal function and urinalysis in different-age patients with Down syndrome, because early detection of renal disorders may prevent or slow down the progression and could be beneficial for increasing survival.

The Underlying Relationship between Keratoconus and Down Syndrome.

Keratoconus (KC) is one of the most significant corneal disorders worldwide, characterized by the progressive thinning and cone-shaped protrusion of the cornea, which can lead to severe visual impairment. The prevalence of KC varies greatly by ethnic groups and geographic regions and has been observed to be higher in recent years. Although studies reveal a possible link between KC and genetics, hormonal disturbances, environmental factors, and specific comorbidities such as Down Syndrome (DS), the exact cause of KC remains unknown. The incidence of KC ranges from 0% to 71% in DS patients, implying that as the worldwide population of DS patients grows, the number of KC patients may continue to rise significantly. As a result, this review aims to shed more light on the underlying relationship between KC and DS by examining the genetics relating to the cornea, central corneal thickness (CCT), and mechanical forces on the cornea, such as vigorous eye rubbing. Furthermore, this review discusses KC diagnostic and treatment strategies that may help detect KC in DS patients, as well as the available DS mouse models that could be used in modeling KC in DS patients. In summary, this review will provide improved clinical knowledge of KC in DS patients and promote additional KC-related research in these patients to enhance their eyesight and provide suitable treatment targets.

Suspicions regarding the genetic inheritance of acute lymphoblastic leukemia in patients with down syndrome.

Children with Down syndrome (DS) are at markedly increased risk for acute lymphoblastic leukaemia (ALL). DS is caused by trisomy of chromosome 21 affecting approximately 1 in 732 newborns in the USA. ALL is the most common cancer in children and constitutes approximately 25% of cancer diagnoses among children under the age of 15. Different protocols for treatment and management of paediatric ALL are available; however, DS children with ALL (DS-ALL) have increased risk of therapy-related toxicity compared to those without DS. Herein, we summarize the available literature on inherited predisposition for ALL, and possibilities for molecular therapy and treatment for DS-ALL patients.

A Better Understanding of Moyamoya in Trisomy 21: A Systematic Review.

Moyamoya disease is defined as stenosis of the internal carotid artery or the middle, anterior or posterior cerebral arteries with considerable collateral development. This collateral vessel has a particular appearance in angiographic examinations. Moyamoya syndrome is a term used to describe when moyamoya disease occurs in conjunction with other systemic disorders. One of the associations is Down syndrome. Moyamoya syndrome is very common in patients with Down syndrome, and the cause for this is unknown. The majority of patients present in their first decade, with the clinical presentation varying with age. The cause of moyamoya syndrome in people with trisomy 21 is unknown. This research aimed to learn more about the genesis and pathology of moyamoya syndrome in people with Down syndrome. The Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines were used to conduct this systematic review. Several publications connected to this topic were searched through a comprehensive database search. They were narrowed down to a final number of ten articles after applying inclusion and exclusion criteria and analyzing the quality of each work. Several possibilities were presented in these final papers to explain the link between moyamoya syndrome and trisomy 21. Trisomy 21 patients have a genetic predisposition to vascular problems. The RNF213 gene may interact with the genes on chromosome 21 that influence vascular physiology and elasticity in patients with Down syndrome, resulting in the whole picture of moyamoya syndrome.