Genetic Disorders Research Articles

The economic and social burden of congenital thrombotic thrombocytopenic purpura (cTTP) in Italy

Background: Congenital thrombotic thrombocytopenic purpura (cTTP) is a rare genetic disorder characterized by an abnormal clotting process leading to serious health complications such as thrombocytopenia and hemolytic anemia. Despite its clinical significance, the estimated broader economic and social impacts in Italy on patients and society remain underexplored. Methods: A detailed questionnaire, developed and validated by a panel of cTTP experts, was distributed to healthcare professionals and patient associations to gather comprehensive data on the economic and social burden of cTTP in Italy. The study was focused on direct and indirect costs associated with the disease management of 15 patients with cTTP, as well as out-of-pocket expenses incurred by patients. Results: The analysis revealed that of the 15 patients diagnosed with cTTP in Italy, 60% were adults aged 40-55 years. Productivity loss and diminished quality of life dominated the economic burden of cTTP, accounting for 81.05% of total costs. Direct medical costs, while substantial, represented a smaller portion of the overall financial impact. Additionally, out-of-pocket expenses, though constituting the smallest fraction, underscored the financial contributions made by patients towards their own care management. Conclusion: The findings underscore the need for a multidisciplinary and holistic approach to cTTP management that extends beyond the clinical treatment. Addressing the economic and social implications of the disease is crucial for improving patient well-being and ensuring the sustainability of healthcare systems. The study advocates for increased awareness, research, and access to care for cTTP patients, highlighting the importance of comprehensive support networks to mitigate the disease’s broader societal impacts, estimated to be around 2 million euro for 15 patients in 10 years.

Unveiling homozygous familial hypercholesterolemia in Greece: a comprehensive analysis of baseline traits and LDL goal achievement in adults from the HELLAS-FH Registry

Abstract Background Homozygous familial hypercholesterolemia (HoFH) is a severe genetic disorder characterized by markedly elevated low-density lipoprotein cholesterol (LDL-C) levels. This study aimed to analyze demographic characteristics, lipid profile, and rate in achieving LDL-C targets in adult HoFH patients in Greece. Methods This is a cross-sectional analysis of the Hellenic Familial Hypercholesterolemia Registry (HELLAS-FH). Adults with genetically or clinically diagnosed HoFH were included. Median LDL-C levels were assessed during HoFH diagnosis and enrollment. Results Seventeen HoFH adults (mean age 41 years and mean age at diagnosis 31 years, men 58.8%). Genetic confirmation of HoFH was available in 10 patients, while the remaining were diagnosed based on clinical criteria. Family history of atherosclerotic cardiovascular disease was documented in 70.5% of patients. Clinical presentations varied, with 47.0% exhibiting tendon xanthomas, 17.6% xanthelasmas, 23.5% corneal arcus, and 52.9% premature coronary artery disease (CAD). Predominant treatment involved statins (88.2%), ezetimibe (58.8%),PCSK9i (23.5%), lomitapide (29.4%), while LDL apheresis was utilized in 23.5%. Median LDL-C levels were 407 mg/dL (10.53 mmol/L) at diagnosis and 226 mg/dL (5.84 mmol/L) at enrollment. None of the patients achieved the LDL-C target set by the 2019 EAS/ESC Guidelines. Conclusion The challenges of delayed diagnosis, undertreatment, and unattained LDL-C targets persist in HoFH management in Greece, emphasizing the critical need for effective lipid-lowering interventions to mitigate cardiovascular risk.

Systematic review of thyroid function in NKX2-1-related disorders: Treatment and follow-up.

NKX2-1, a crucial transcription factor in thyroid, lung, and brain development, is associated with rare disorders featuring thyroid dysfunction, neurological abnormalities, and respiratory symptoms. The primary challenge in managing NKX2-1-related disorders (NKX2-1-RD) is early diagnosis of the genetic defect and treating specific endocrine disorders. Levothyroxine (LT4) serves as the standard hypothyroidism treatment, with required dosages influenced by the severity of the individual's disorder, which varies widely among affected individuals. This systematic review aims to assess the effectiveness of LT4 treatment in NKX2-1-RD and explore optimal dosing strategies. The primary focus is on the challenges associated with the prompt diagnosis of genetic defects, rather than the established treatment protocols for individual endocrine failures. Adhering to PRISMA guidelines, the review includes 42 studies involving 110 genetically confirmed NKX2-1-RD patients with hypothyroidism. The study investigates congenital hypothyroidism as the most prevalent endocrine alteration, along with gestational and overt hypothyroidism. The administration of LT4 treatment, dosages, and patient responses are analyzed. Among the findings, congenital hypothyroidism emerges as the predominant endocrine alteration in 41% of patients. Notably, LT4 treatment is administered in only 10% of cases, with a mean dose of 52 μg/day. The variability in initiation and dosage is likely influenced by the age at diagnosis. Positive responses, characterized by TSH adjustments within normal ranges, are observed in 11 monitored patients. Early detection of congenital hypothyroidism is emphasized for timely LT4 initiation. Challenges in standardization are highlighted due to the variability in clinical manifestations and diagnostic procedures across NKX2-1-RD cases. While this review provides valuable insights into thyroid and pituitary disease treatment, limited details on LT4 treatment represent a significant study limitation. Key reporting points for future case studies are proposed to enhance the understanding and management of NKX2-1-RD hypothyroidism.

Pnn deficiency alters expressions of calcium handling proteins and impairs nuclear envelope structure in cardiomyocytes

Abstract Pnn is a multi-functional protein playing roles in the regulation of gene transcription, mRNA alternative splicing, as well as cell-cell connection. Previous studies suggested an association between Pnn genetic defects and arrhythmogenic right ventricular cardiomyopathy (ARVC) in human. In this study, we applied an inducible cardiomyocyte-specific Pnn depletion mouse model (Myh6-CreERT2, Pnnflox/flox) to determine the impact of loss of Pnn on cardiac structure and function in mice. Six weeks after inducing Pnn gene disruption, electrocardiographic abnormalities, ventricular dilatation, and reduced left ventricular ejection fraction (LVEF) were observed in mice with loss of Pnn in cardiomyocytes. Histopathological examinations showed that the proliferation of cardiac fibroblasts and expression of α-smooth muscle actin were increased with Pnn depletion, while the cell-cell connection between cardiomyocytes were impaired. In addition to impaired intercalated discs, loss of Pnn also altered the distribution and expression of nuclear envelope proteins and the linker of nucleoskeleton and cytoskeleton (LINC) complex proteins, such as nuclear lamins, Emerin, and SUNs, in cardiomyocytes. Microarray analysis as well as subsequent RT-PCR and Western blots also indicated that loss of Pnn regulated myocardial expressions of genes responsible for calcium handling, such as RYR2, Atp2a2, Slc8a1, and Kcnj3. Furthermore, infiltrations of macrophages and neutrophiles were observed in the myocardium with Pnn depletion, while expression levels of oxidative stress-associated proteins were also significantly regulated by Pnn depletion. In conclusion, Pnn plays an essential role in the maintenance of intercalated disc integrity and nuclear envelope structure of cardiomyocytes, while cardiomyocyte-specific loss of Pnn impairs the calcium handling and leads to arrhythmogenic dilated cardiomyopathy in mice.Cardiac MRI of mice with Pnn depletionMyocardial expression of SUN2 and Emerin

Cancer ameliorates cardiac dysfunction and suppresses fibrosis in a mouse model for Duchenne muscular dystrophy

Abstract The interplay between heart failure and cancer represents a double-edged sword. Whereas cardiac remodeling promotes cancer progression, tumor growth suppresses cardiac hypertrophy and reduces fibrosis deposition. Whether these two opposing interactions are connected awaits to be determined. In addition, it is not known whether cancer affects solely the heart, or if other organs are affected as well. To explore the dual interaction between heart failure and cancer, we studied the human genetic disease Duchenne Muscular Dystrophy (DMD) using the MDX mouse model. We analyzed fibrosis and cardiac function as well as molecular parameters by multiple methods in the heart, diaphragm, lungs, skeletal muscles, and tumors derived from MDX and control mice. Surprisingly, cardiac dysfunction in MDX mice failed to promote murine cancer cell growth. In contrast, tumor-bearing MDX mice displayed reduced fibrosis in the heart , skeletal and diaphragm muscles, resulting in improved cardiac function. The latter is at least partially mediated via M2 macrophage recruitment to the heart and diaphragm muscles. Remarkably, an analysis of of cytokines in the blood of tumor-bearing and non-tumor-bearing MDX mice initially revealed several potential factors. These factors hold promise in significantly reducing fibrosis within our model. Administering these factors simultaneously to MDX mice led to decreased fibrosis in the heart, diaphragm, and skeletal muscles, along with an improvement in cardiac function. Collectively, our data support the notion that the effect of heart failure on tumor promotion is independent of the improved cardiac function in tumor-bearing mice. Reduced fibrosis in tumor-bearing MDX mice stems from the suppression of new fibrosis synthesis and the removal of existing fibrosis. These findings offer potential therapeutic strategies for DMD patients, fibrotic diseases, and cardiac dysfunction.Tumor growth suppresses fibrosisGraphical representation

Clinical genome sequencing in patients with suspected rare genetic disease in Peru

There is limited access to molecular genetic testing in most low- and middle-income countries. The iHope program provides clinical genome sequencing (cGS) to underserved individuals with signs or symptoms of rare genetic diseases and limited or no access to molecular genetic testing. Here we describe the performance and impact of cGS in 247 patients from three clinics in Peru. Although most patients had at least one genetic test prior to cGS (70.9%), the most frequent was karyotyping (53.4%). The diagnostic yield of cGS was 54.3%, with candidate variants reported in an additional 22.3% of patients. Clinical GS results impacted clinician diagnostic evaluation in 85.0% and genetic counseling in 72.1% of cases. Changes in management were reported in 71.3%, inclusive of referrals (64.7%), therapeutics (26.3%), laboratory or physiological testing (25.5%), imaging (19%), and palliative care (17.4%), suggesting that increased availability of genomic testing in Peru would enable improved patient management.

Impact of high intensity and long duration exercise in genetic arrhythmogenic left ventricular cardiomyopathy

Abstract Background Arrhythmogenic left ventricular (LV) cardiomyopathy (ALVC) is a genetic disease associating extensive LV myocardial fibrosis with or without dysfunction and no or mild right ventricle (RV) involvement, at risk of life-threatening ventricular arrhythmias (VA). While high intensity (HI) and long duration (LD) exercise has been identified as a precipitating factor of RV dysfunction and VA in arrhythmogenic RV cardiomyopathy including in asymptomatic genetic variant carriers, the impact of exercise on disease phenotype and risk is not known in ALVC. Objective To study the relationship between practicing HI and LD exercise and the risk of developing an ALVC phenotype and its severity. Methods In a monocentric retrospective observational study, patients with a pathogenic variant in common ALVC genes (DSP, FLNC, DES, PLN, RBM20, TMEM43), including asymptomatic carriers without ALVC phenotype, were interviewed about their physical practice from age 7 to the time of genetic or disease diagnosis. Intensity and weekly duration of each activity were reported. HI and LD exercise were defined as having practiced at least 1 sport with an intensity ≥ 6 METs and ≥ 2.5 hours/week respectively. We studied the association of HI and LD exercise practice with the risk of ALVC phenotype occurrence and its severity, derived from clinical, ECG and imaging data. Results 114 out of 128 eligible patients answered the questionnaire and were included (85 (74.6%) with a DSP variant, 22 FLNC (19.3%), 6 DES (5.3%), 1 RBM20 (0.9%)). 35 were probands (31%) and 79 relatives (69%) among 46 families. 31 (27%) had no ALVC phenotype at the time of genetic diagnosis. Mean age at diagnosis was 41±18. 62 (54%) patients were women. 97 (85%) had practiced at least one sport, among which 81 (83.5%) at HI and 79 (81.4%) of LD. Median lifetime exercise dose was 18.5 MET.h/week. There were no differences in HI and LD exercise practice between probands and relatives (74.3% vs 69.6%, p=0.6 and 74.3% vs 67.1%, p=0.4 respectively), as well as between patients with and patients without ALVC phenotype at the time of diagnosis (74.7% vs 61.3%, p=0.2 and 72.3% vs 61.3%, p=0.3 respectively). Phenotypic features at diagnosis did not differ between patients with and without HI and LD practice (Table 1). Multivariate analysis adjusted on age and gender showed that HI and LD exercise were not significantly associated with an increased risk of developing an ALVC phenotype (Odds Ratio [95% confidence interval] for age, gender, HI and LD exercise were 1.03 [1.01-1.06] (p=0.013), 1.41 [0.58 ; 3.47] (p=0.45), 2.15 [0.63 ; 7.27] (p=0.22) and 1.17 [0.35 ; 3.87] (p=0.79) respectively). Phenotypic features at diagnosis did not differ across observed quartiles of lifetime exercise dose (Table 2). Conclusion Practicing HI and LD exercise was not associated with an increased risk of developing an ALVC phenotype and its severity at the time of diagnosis in genetic ALVC variant carriers.

Clinical reality and challenges with familial hypercholesterolemia patients management. 2024 results from the Regional Center for Rare Diseases (RCRD) Registry in Poland

Abstract Background HeFH is one of the most prevalent genetic diseases significantly increasing the risk of CVD events and mortality. Despite new achievements with earlier diagnosis and new effective drugs, most of heFH patients do not achieve LDL-C goal and are still on residual CVD risk. Purpose We aimed to present the most recent data from the regional FH registry in Poland to show the challenges and reality of everyday clinical management with FH patients. Methods The registry is conducted at the RCRD in the 2nd largest, supraregional hospital in Poland. The main inclusion criteria were being phenotypically or genetically diagnosed with FH. Nonadherence was investigated based on detailed interview, monitoring the treatment’s effects and purchasing prescribed medications. For this analysis we investigated only adult FH patients from the registry. Due to small number of cases (n=5), patients treated with inclisiran were not included in this analysis. Results We included 142 consecutive heFH patients at mean age 45,8±14,9 years (min/max 18-75 years; 60% women). Mean BMI was 29.6±5.52 kg/m2, mean baseline TC was 282.9±80 mg/dl (the highest observed was 600 mg/dl), LDL-C 204.2±72.5 mg/dL (the highest observed -762 mg/dl), TG - 151.1±123.4 mg/dl, Lp(a) 37.6±41.5 mg/dl and HDL-C - 52.3±14.2 mg/dl. Most patients were diagnosed with LDLR (72%) or APOB (24%) mutations. High intensity statin therapy was used in 74.3% of patents, ezetimibe (mostly as a part of combination LLT) in 47.2%, and PCSK9 inhibitors in all those that met the reimbursement criteria – 25.6% of FH patients. Non-adherence to statin therapy and ezetimibe in the follow up of 2 years was 27%. In patients treated with statin therapy and ezetimibe mean achieved LDL-C was 153.6±82.82 mg/dl and on triple therapy - 64.5±43.73 mg/dl. Mean achieved LDL-C in the investigated population was 87.9±55.5 mg/dl. LDL-C goal was achieved in 39% of patients – in those treated with triple therapy with PCSK9 inhibitors it was 57.14%, and in those on statins and ezetimibe only 27.1%. Combination therapy of statins and ezetimibe did not significantly change baseline Lp(a) level (p=0.109), but when PCSK9 inhibitors were introduced the mean Lp(a) reduction by 34.2% (p=0.049) was observed. Based on the multivariable regression analysis, the following factors played the most important role for FH patients to be on LDL-C target: DLCN total score (OR 1.21, 95%CI: 1.04-1.40; p=0.013), DLCN category (10.39, 1.43-75.29; p=0.021), ezetimibe use (4.78, 1.15-19.92; p=0.031), and PCSK9 inhibitors use (4.56; 1.40-14.86; p=0.012). Conclusions FH patients in Poland are diagnosed definitely too late (45 years) and most of them are still not on LDL-C goal. Double and especially triple therapy significantly, even 5 times, increase the chance of achieving LDL-C goal, therefore PCSK9 inhibitors should be available for all FH patients, without the limitations existing currently e.g., within B101 drug program in Poland.

AAV-based TCAP delivery rescues mitochondria dislocation in limb-girdle muscular dystrophy R7.

Limb-girdle muscular dystrophy R7 is a rare genetic disease caused by homozygous or compound heterozygous variants in the titin-cap (TCAP) gene that results in the absence of the protein telethonin. The primary pathological features of limb-girdle muscular dystrophy R7 are fiber size variation, nuclear centralization, and abnormal mitochondrial distribution. The mechanisms underlying this disease are unclear, and there is currently no specific treatment for limb-girdle muscular dystrophy R7. This study established a Tcap-deficient mouse model to explore the disease mechanism of mitochondria dislocation and potential therapeutic strategies. We use methods such as proteomics, immunofluorescence, histopathological staining, and western blotting to explore the mechanism of mitochondrial dislocation. Moreover, in the quest for a prospective therapeutic intervention for this disorder, the adeno-associated virus serotype 2/9 was employed to deliver the Tcap gene into the muscles of these mice, facilitating preclinical experimentation. After 2 months and 7 months, the muscular phenotype was evaluated and selected mice were humanely euthanized for subsequent molecular and histological analysis. The phenotype of Tcap-/- mice mimicked that observed in individuals diagnosed with limb-girdle muscular dystrophy R7. This study elucidated the mechanism of mitochondrial dislocation in limb-girdle muscular dystrophy R7. Through our in vitro experiments, we discovered that telethonin aids in preserving the integrity of desmin by preventing truncation at the N-terminus. Additionally, telethonin combined with desmin and colocalized at the Z-disc. Research has shown that the Tcap gene plays a crucial role in controlling the desmin cytoskeleton organization. The absence of telethonin leads to a collapsed desmin cytoskeleton. This causes disorganization of the mitochondrial network, leading to mitochondrial dysfunction. In addition, the study investigated the efficacy of adeno-associated virus (AAV)-mediated Tcap replacement in Tcap-/- mice. By intramuscular delivery of AAV, we observed dramatic improvements in muscle phenotype, muscle pathology, CK levels, muscle magnetic resonance imaging, mitochondrial network organization, and mitochondrial function. The results of this study demonstrated that telethonin deficiency led to desmin cytoskeleton collapse that caused mitochondrial dislocation. AAV-mediated replacement therapy could be a promising safe and efficient treatment option for limb-girdle muscular dystrophy R7. The study highlights the potential of AAV-mediated replacement therapy for specific types of limb-girdle muscular dystrophy.

Artificial Intelligence in Medical Diagnostics

Artificial intelligence (AI) is an essential tool in the medical sector that contributes significantly to medical imaging, medical pathology, histology, genomic study, predictive analysis, etc. It is being increasingly used not only in breast and lung cancer diagnosis and screening, and genetic disease identification but also in personalized decision-making during the treatment of these diseases. The quality and availability of unbiased data is a key challenge. Algorithmic bias and interpretability are significant concerns as well. Improving the use of AI in medical diagnostics could be achieved through continuous monitoring, access to highly accurate datasets, and timely intervention by healthcare professionals. J Bangladesh Coll Phys Surg 2024; 42: 379-382

Vector Field Heterogeneity (VFH) as a novel quantitative marker of electrical disarray in Arrhythmogenic CardioMyopathy (ACM) with ventricular tachycardia

Abstract Background ACM is a hereditary condition characterized by fibrofatty infiltration and replacement of cardiac myocytes predominantly presenting with ventricular arrhythmias (VA). Cardiac imaging allows for detailed structural phenotyping of scar patterns in ACM. Yet, there is a lack of tools to objectively quantify the electrical substrate alterations that may enable a more precise identification of critical sites that predispose to VA. Purpose To quantify locally disorganized cardiac electrical propagation wavefronts using the Vector Field Heterogeneity (VFH) metric from high-density multi-electrodes in patients with ACM with VT and compare to healthy controls. Methods High density epicardial substrate maps acquired with a 16-pole grid catheter during SR or RV pacing in patients with ACM with VA, who underwent clinically indicated catheter ablation, were retrospectively reviewed. Patients with structurally normal heart and idiopathic VA with epicardial ablation were analysed as a control group. Unipolar contact mapping data was exported & processed offline. From the 4×4 electrode array EGMs, vector maps of the directions of electrical propagation for recorded sites were computed. The VFH was then computed as a quantitative measure of local heterogeneity of propagation, with higher VFH expected to correlate with sites of (micro)structural tissue alterations. VFH was compared between ACM and control patients as well as at sites of normal, border zone & scar based on omnipolar voltage in ACM patients (>1.5mV, 0.5mV–1.5mV, <0.5mV, respectively). Results 10 patients with ACM (70% male, aged 52 ±18 years, ARVC 70%, biventricular 30%, RVEF 40.7±4.7%, LVEF 66±12%) and 2 patients with structurally normal heart (female, 38 & 61 years) were included. Epicardial maps had an average of 9258 ±5412 EGM points. Median VFH was statistically significantly higher in the ACM cohort compared to control for global maps (0.33±0.33 vs 0.13±0.22, p<0.001) and at sites with voltage >1.5mV (i.e. greater disorganization in ACM, p<0.001). In ACM, assessment of VFH according to omnipolar voltage sites (as a surrogate of scar) showed a quantifiable statistically significant increase in electrical disorganized propagation at sites of lower voltage (<0.5mV, median VFH 0.53±0.36) compared to borderzone (0.5-1.5mV, VFH 0.29±0.41) and normal voltage (>1.5mV, VFH 0.15±0.26), p <0.001 respectively. Conclusion Heterogenous electrical propagation as quantified by VFH is significantly increased in patients with ACM at sites of scar, but importantly also in areas of normal voltages when compared to non-ACM controls, possibly indicating microstructural alterations that are missed in traditional assessments of the arrhythmogenic substrate. Identifying and quantifying disorganized conduction patterns by VFH is a promising new mapping approach that could allow improved substrate characterization. Its diagnostic value to guide ablation therapy is currently being validated.VFH Metric ACM and ControlVFH Map Examples

Understanding primary ciliary dyskinesia.

Primary ciliary dyskinesia (PCD) is a rare, inherited disease characterized by impaired motile ciliary function leading to chronic sinopulmonary disease, persistent middle ear effusions, laterality defects, and subfertility. Over fifty PCD-associated genes have also been identified, which have provided new insights into the processes involved into ciliary assembly, structure, and function. Historically, the diagnosis of PCD was based on the presence of ultrastructural defects in the ciliary axoneme but with identification of a growing number of disease-associated genes, genetic testing has become a first-line diagnostic tool. Other approaches have also evolved, that have improved our diagnostic capabilities. Treatments for PCD have lagged, and though our growing understanding of the genetic and pathophysiological bases of the disease of PCD may yield to better therapeutic strategies.

Genetic Variants Supporting the Diagnosis of Primary Ciliary Dyskinesia in Japan.

Primary ciliary dyskinesia (PCD; OMIM 244400) is a rare genetic disorder affecting motile cilia and is characterized by impaired mucociliary clearance in the airway epithelium that leads to chronic oto-sinopulmonary manifestations. To date, over 50 PCD-causing genes have been identified, with these genes and their variants varying globally across populations. We performed targeted resequencing of 42 PCD-causative genes in 150 Japanese patients suspected of having PCD and identified pathogenic or likely pathogenic variants in 51 patients. Among these, 24 patients exhibited a homozygous deletion of DRC1 exons 1-4, the most common cause of PCD in Japan. The allele frequency of this deletion was estimated at 0.0034 (95% CI: 0.0025-0.0044), based on bioinformatic analysis of 7906 whole-genome sequences from the general Japanese population. Additionally, RNA sequencing of nasal samples supplemented in silico variant predictions, aiding in the identification of causative variants. Considering potential ethnic differences, it is essential to accumulate global data on these variants and their functional impacts.

ANÁLISE ACERCA DO CONHECIMENTO DE GESTANTES E PUÉRPERAS SOBRE A IMPORTÂNCIA DA TRIAGEM NEONATAL EM UMA UNIDADE DE SAÚDE E SEUS IMPACTOS QUANDO NEGLIGENCIADA

Neonatal screening based on the “heel prick test” biological matrix is a fundamental test performed in newborns for the screening of genetic, metabolic, and infectious diseases that can lead to health problems or irreversible deficiencies if neglected. The heel prick test is a public health policy adopted in many countries, including Brazil, and is widely recognized as one of the most important procedures in preventive medicine, in order to guarantee comprehensive care and universal access. Thus, the National Neonatal Screening Program (PNTN) was created in 2001, to promote and implement screening actions with a special focus on prevention, early intervention, and monitoring of children whose disease is included in the program's criteria. It is necessary that the health team guide the pregnant woman during the prenatal period, and the puerperal women, as well as their respective companions, on how and where to perform the “heel prick test”, highlighting its purpose to ensure effective awareness. Therefore, the present study aims to analyze the level of knowledge about neonatal screening in pregnant and postpartum women in the public health network. As well as introduce them to the importance of tracking in a timely manner to manage positive cases through monitoring and follow-up during treatment.

Regulation of HTT mRNA Biogenesis: The Norm and Pathology

Huntington’s disease (HD) is a neurodegenerative disorder caused by the expansion of the CAG repeat in exon 1 of the HTT gene, leading to the formation of a toxic variant of the huntingtin protein. It is a rare but severe hereditary disease for which no effective treatment method has been found yet. The primary therapeutic targets include the mutant protein and the mutant mRNA of HTT. Current clinical trial approaches in gene therapy involve the application of splice modulation, siRNA, or antisense oligonucleotides for RNA-targeted knockdown of HTT. However, these approaches do not take into account the diversity of HTT transcript isoforms in the normal conditions and in HD. In this review, we discuss the features of transcriptional regulation and processing that lead to the formation of various HTT mRNA variants, each of which may uniquely contribute to the progression of the disease. Furthermore, understanding the role of known transcription factors of HTT in pathology may aid in the development of potentially new therapeutic tools based on endogenous regulators.

Universal newborn screening using genome sequencing: early experience from the GUARDIAN study.

For more than 20 years there has been speculation about a future in which newborns are routinely screened at birth for genetic disorders using genome sequencing, but prospective large-scale studies assessing this vision have only recently begun. Genome sequencing may provide a means of expanding the scope of conditions included in newborn screening programs and improving the positive predictive value of traditional newborn screening. However, the use of genome sequencing for newborn screening has also raised concerns including acceptability, equity, and scalability. By reviewing the initial results of the GUARDIAN study and contrasting them with other pilot studies investigating the use of genome sequencing for large-scale newborn screening, we highlight how the lessons learned from these studies are shaping the future for the implementation of truly universal and equitable newborn genomic screening.

Familial osteochondrodysplastic and cardiomyopathic syndrome in Chianina cattle.

Skeletal dysplasia encompasses a heterogeneous group of genetic disorders characterized by an abnormal development of bones, joints, and cartilage. Two Chianina half-sibling calves from consanguineous mating with congenital skeletal malformations and cardiac abnormalities were identified. To characterize the disease phenotype, to evaluate its genetic cause, and to determine the prevalence of the deleterious alleles in the Chianina population. Two affected calves, their parents and 332 Chianina bulls. The affected animals underwent clinicopathological investigation. Whole-genome sequencing trio-approach and PCR-based assessment of the frequency of TDP-glucose 4,6-dehydratase (TGDS) and laminin subunit alpha 4 (LAMA4) alleles were performed. The cases presented with retarded growth, poor nutritional status associated with muscular atrophy and angular deformities of the hindlimbs. Radiologic examination identified generalized osteopenia and shortening of the limb long bones. Necropsy showed osteochondrodysplastic limbs and dilatation of the heart right ventricle. On histological examination, the physeal cartilages were characterized by multifocal mild to moderate loss of the normal columnar arrangement of chondrocytes. Osteopenia also was observed. Genetic analysis identified a missense variant in TGDS and a splice-site variant in LAMA4, both of which were homozygous in the 2 cases. Parents were heterozygous and allele frequency in the Chianina population for the TGDS variant was 5% and for the LAMA4 variant was 2%. Genetic findings identified 2 potentially pathogenic alleles in TGDS and LAMA4, but no clear mode of inheritance could be determined.

Identifying DNA Variants in a Turkish Cohort with Inner Ear Anomalies.

To determine the genetic causes of sensorineural hearing loss (SNHL) associated with inner ear anomalies, 11 unrelated Turkish individuals diagnosed with SNHL and an inner ear anomaly using temporal bone computed tomography and inner ear magnetic resonance imaging underwent exome or whole genome sequencing to identify underlying genetic defects. None of the individuals was diagnosed with a recognized syndrome. Four of the 11 probands were homozygous for SLC26A4 variants, c.283G>A, c.845G>A, c.1061T>C, and c.1198delT. Another proband was homozygous for a TECTA variant, c.4163G>A. Patients with variants of the SLC26A4 gene had bilateral enlarged vestibular aqueduct, bilateral incomplete partition type 2 anomaly, bilateral hypoplastic cochlea and bilateral enlarged vestibular aqueduct plus hypoplastic cochlea anomaly. Patients with the variant TECTA gene had bilateral hypoplastic cochlea. This study identified variants of SLC26A4 in 36% of probands with inner ear anomalies. While we identified a variant of the TECTA gene in a proband with cochlear hypoplasia, further studies are needed to see if TECTA variants can cause cochlear malformations.

A survey to analyze the need of genetic counseling among doctors in Lahore, Pakistan.

Pakistan with a population of approximately 200 million people faces a significant burden of genetic disorders. Higher preference for consanguinity (73%) is one of the significant reasons. Despite being a hub for rare genetic disorders, the country lacks professionally trained genetic counselors due to the absence of postgraduate degree programs or diplomas in genetic counseling. This shortage of specialized personnel results in inadequate and limited genetic counseling practices nationwide. This study aimed to highlight the urgent need for genetic counseling in Pakistan, focusing on the gaps within both society and the healthcare infrastructure. A survey-based study involving n = 101 participants was conducted to assess the demand for genetic counseling among medical professionals in Lahore, Pakistan. The study targeted five categories of medical specialists-gynecologists, oncologists, psychiatrists, pediatricians, and ultrasonologists-working in both private and public healthcare settings in Lahore. The survey included a questionnaire covering demographic information, 10 general questions, and a case study with follow-up questions. The survey was conducted both online and through in-person visits. Our findings reveal a significant lack of awareness among healthcare providers, with 91.1% of respondents unaware of any genetic counseling services or genetic counselors in Lahore. The research underscores the crucial role of genetic counselors, with the vast majority (99%) of specialists expressing an urgent need for their presence in Pakistan's healthcare system. This study highlights that only qualified genetic counselors can effectively address genetic issues. Furthermore, it advocates for the introduction of specialized professional training programs to address this pressing need in the country.

A Pediatric Case of Multiple Pilomatricomas: Assessing the Risk of Genetic Disorders.

Pilomatricomas are benign tumors from hair matrix cells, often associated with genetic disorders such as myotonic dystrophy. We report a case of multiple pilomatricomas in a 12-year-old boy, suggesting they may indicate underlying hereditary diseases, requiring careful post-surgical follow-up and examination.