Genetic Counseling and Genome Sequencing in Pediatric Rare Disease

The impact of rare diseases on the quality of life in paediatric patients: current status

Rare diseases, also known as orphan diseases, are a group of disorders that affect a small percentage of the population. Despite individually affecting a small number of people, collectively, they impact millions worldwide. This is particularly significant in paediatric patients, highlighting the global scale of the issue. This review delves into the exact prevalence of rare diseases among children and adolescents and their diverse impact on the quality of life of patients and their families. The review sheds light on the complex interplay of genetic and environmental factors contributing to these conditions and the diagnostic challenges and delays often encountered in identifying and categorising these diseases. It is noted that although there have been significant strides in the field of genomic medicine and the development of orphan drugs, effective treatments remain limited. This necessitates a comprehensive, multidisciplinary approach to management involving various specialities working closely together to provide holistic care. Furthermore, the review addresses the psychosocial and economic burdens faced by families with paediatric patients suffering from rare diseases, highlighting the urgent need for enhanced support mechanisms. Recent technological and therapeutic advancements, including genomic sequencing and personalized medicine, offer promising avenues for improving patient outcomes. Additionally, the review underscores the role of policy and advocacy in advancing research, ensuring healthcare access, and supporting affected families. It emphasises the importance of increased awareness, education, and collaboration among healthcare providers, researchers, policymakers, and patient advocacy groups. It stresses the pivotal role each group plays in improving the diagnosis, treatment, and overall quality of life for paediatric patients with rare diseases.

Lived Experience of Patients and Caregivers in Rare Genetic Neurological Gene Therapy Clinical Trials in Children

To date, sparse attention has been paid to the importance of the "lived experience" of participants and their caregivers in pediatric gene therapy (GT) trials for rare genetic neurological disorders. Pediatric GT studies differ meaningfully from adult GT studies as the decision to participate involves a dyad: the child participant and their caregiver(s). As a multistakeholder group of authors, we are a diverse group with expert perspectives on the social, emotional, physical, and logistical burdens/benefits of trial participation and the myriad ways they affect pediatric GT research. For both pragmatic and ethical reasons, it is essential to prioritize addressing child participant and adult caregiver needs and concerns when designing and conducting GT clinical trials in pediatric populations with rare genetic neurological disorders. We use the term "lived experience" in reference to how people think about and make decisions regarding participation in research studies and how they articulate the emotional, social, ethical, and equity tradeoffs that impact their lives and illness experience. In this article, we describe why accounting for child participants' and adult caregivers' lived experience and addressing pertinent equity issues are essential when designing and conducting pediatric GT trials for rare genetic neurological diseases.

Case Report: The first Korean familial case of BCAP31-related deafness, dystonia, and cerebral hypomyelination

Deafness, dystonia, and central hypomyelination (DDCH) syndrome (OMIM #300475) is a rare X-linked genetic disorder characterized by developmental delays, deafness, central hypomyelination, and dystonia. We report the first Korean familial case involving twin boy and girl carrying a novel pathogenic BCAP31 variant which was inherited from their mother. The male proband, born prematurely with very low birth weight (VLBW), exhibited severe global developmental delay, microcephaly, failure to thrive, dystonia, seizures, sensorineural hearing loss (SNHL) requiring cochlear implantation, and mild facial dysmorphism. A brain MRI revealed white matter atrophy, thinning of the corpus callosum, and delayed myelination. The twin sister presented with mild developmental delays and bilateral SNHL but did not experience seizures or dystonia. Their mother also had bilateral SNHL. Whole genome sequencing identified a hemizygous pathogenic variant, c.247C>T (p.Gln83Ter), in the BCAP31 in the proband. The variant was also found in his mother and twin sister, who exhibited less severe symptoms. Early genetic evaluation via next-generation sequencing is crucial for timely diagnosis and intervention, particularly in VLBW infants with genetic disorders. This report expands the understanding of genotype-phenotype correlations in DDCH syndrome and highlights the variable phenotypes in manifesting females.

Characterization of patients treated at a rare disease referral service: a descriptive study, 2016-2021

OBJECTIVE

To analyze the first referral service for rare diseases accredited by the Brazilian Ministry of Health, focusing on referral from the primary healthcare network through to diagnosis.

METHODS

This is a descriptive study with patients treated between 2016 and 2021 at a referral hospital service located in Curitiba, Paraná, Brazil. Clinical and epidemiological data were obtained from medical records, as were the results of genetic tests at the hospital's clinical analysis laboratory. Qualitative data were expressed as absolute and relative frequencies, while quantitative data were expressed as medians and interquartile ranges and compared using the Kruskal-Wallis test.

RESULTS

The study included 1,751 cases, 34.1% were diagnosed with rare diseases, with average time until diagnosis being 3.0 years, whereby mucopolysaccharidosis type II (4.0%) and tuberous sclerosis (3.9%) were the most common. Greater length of time for obtaining diagnosis (p-value 0.004) and receiving specialized care (p-value<0.001) was found in patients from the interior region of Paraná state, compared to those residing in Curitiba city and its metropolitan region.

CONCLUSION

Diagnosis of rare diseases occurred in approximately one third of cases. The average time until diagnosis suggests a possible positive impact of implementing the referral service. The longer time until diagnosis and specialized care found among patients from the interior region of Paraná represent challenges regarding adequate referral to specialized services.

Navigating the diagnostic journey of epidermolysis bullosa: a qualitative study of the lived experiences and needs of parents and patients

BACKGROUND

Epidermolysis bullosa (EB) concerns a heterogeneous group of rare genetic skin fragility disorders that result in chronic blistering and wounding. EB significantly affects the daily lives of patients, as well as their families. While advances in diagnostics are improving the speed and accuracy of EB diagnosis, little is known about the experiences and needs of parents and patients throughout their diagnostic journey.

OBJECTIVES

To explore parent and patient perspectives on the EB diagnostic trajectory to gain an in-depth understanding of their lived experiences and needs.

METHODS

Participants were parents of paediatric patients with EB (n = 18) and adult patients with EB (n = 8) recruited from the Dutch EB Registry. After purposive sampling, they participated in semi-structured interviews via video calls to discuss their personal diagnostic trajectory and the subsequent impact of an EB diagnosis on their (family) life. By applying a constructivist approach, a reflexive thematic analysis was executed to facilitate a dynamic and iterative process, involving inductive open coding of transcripts and constant comparison of data.

RESULTS

Ten major themes were developed, representing three distinct groups: (i) parents of children with junctional EB and recessive dystrophic EB; (ii) parents of children with EB simplex and dominant dystrophic EB; and (iii) adult patients with localized EB. The EB diagnostic process appeared to have a diversity of emotional consequences, varying from desperation and uncertainty about the future to clarification and confirmation. The urgent need for a timely diagnosis and accurate prognosis was emphasized, particularly by parents of children with an extensive presentation. Parents and patients expressed shortcomings in clinical practice, with severity ratings in current EB disease terminology, in particular, seeming to have an adverse impact on illness perception, healthcare-seeking behaviour, research participation and engagement in peer support.

CONCLUSIONS

This study describes the lived experience and needs of parents of children with EB and adult patients with EB during the diagnostic process. We found a pressing need to accelerate diagnostics and urge that the EB community should continue working toward ever-faster diagnosis, public awareness and education. While guiding patients along the diagnostic journey, clinicians should focus their support strategies on tailored medical communication while refraining from value-connoted wording.

Non-Genetic Healthcare Providers' Experiences and Perspectives with Rapid Genome-Wide Sequencing in Canadian Neonatal Intensive Care Units

BACKGROUND/OBJECTIVES

Rapid genome-wide sequencing (rGWS) continues to transform the care provided to infants with genetic conditions in neonatal intensive care units (NICUs). Previous research has demonstrated that rGWS has immense benefits on patient care; however, little is known about non-genetic healthcare providers' (HCPs) experiences and perspectives of working with rGWS and supporting families through the rGWS testing process in Canadian NICU facilities. To address this gap, we surveyed and conducted semi-structured interviews with non-genetic HCPs of diverse professions from NICUs in British Columbia.

METHODS

An interpretive description approach was used to analyze interview transcripts to identify patterns and variations in non-genetic HCPs' experiences and perceptions with rGWS.

RESULTS

Participants had varying degrees of exposure to rGWS and levels of comfort with the testing process. Numerous barriers affecting the implementation of rGWS were identified, including low levels of comprehension of rGWS, longer turn-around times than expected, and having to apply for provincial government approval to access testing. Participants desired more education on rGWS, clear guidelines on the use of rGWS in NICUs, and resources for non-genetic HCPs and parents to support implementation.

CONCLUSIONS

The results from this study can inform the development of workflows and educational resources on the use of rGWS in NICUs, helping to ensure that the NICU team is supported to optimize rGWS implementation.

Clinical description and evaluation of 30 pediatric patients with ultra-rare diseases: A multicenter study with real-world data from Saudi Arabia

BACKGROUND

With the advancement of next-generation sequencing, clinicians are now able to detect ultra-rare mutations that are barely encountered by the majority of physicians. Ultra-rare and rare diseases cumulatively acquire a prevalence equivalent to type 2 diabetes with 80% being genetic in origin and more prevalent among high consanguinity communities including Saudi Arabia. The challenge of these diseases is the ability to predict their prevalence and define clear phenotypic features.

METHODS

This is a non-interventional retrospective multicenter study. We included pediatric patients with a pathogenic variant designated as ultra-rare according to the National Institute for Clinical Excellence's criteria. Demographic, clinical, laboratory, and radiological data of all patients were collected and analyzed using multinomial regression models.

RESULTS

We included 30 patients. Their mean age of diagnosis was 16.77 months (range 3-96 months) and their current age was 8.83 years (range = 2-15 years). Eleven patients were females and 19 were males. The majority were of Arab ethnicity (96.77%). Twelve patients were West-Saudis and 8 patients were South-Saudis. SCN1A mutation was reported among 19 patients. Other mutations included SZT2, ROGDI, PRF1, ATP1A3, and SHANK3. The heterozygous mutation was reported among 67.86%. Twenty-nine patients experienced seizures with GTC being the most frequently reported semiology. The mean response to ASMs was 45.50% (range 0-100%).

CONCLUSION

The results suggest that ultra-rare diseases must be viewed as a distinct category from rare diseases with potential demographic and clinical hallmarks. Additional objective and descriptive criteria to detect such cases are needed.

Children With Idiopathic Short Stature: An Expanding Role for Genetic Investigation in Their Medical Evaluation

Short stature in children is a common reason for referral to a pediatric endocrinologist. Many genetic, nutritional, psychological, illness-related, and hormonal causes must be excluded before labeling as idiopathic. Idiopathic short stature is not a diagnosis, but rather describes a large, heterogeneous group of children, who are short and often slowly growing. As new testing paradigms become available, the pool of patients labeled as idiopathic will shrink, although most will have a polygenic cause. Given that many of the new diagnoses are involved in growth plate biology, physical examination should assess for subtle dysmorphology or disproportion of the skeleton that may indicate a heterozygous mutation that in its homozygous state would be apparent. When laboratory evaluations are negative, one may consider genetic testing, such as targeted gene or gene panel, comparative genomic hybridization, or whole exome or whole genome sequencing (respectively). With a known genetic diagnosis, targeted therapy may be possible rather than recombinant human growth hormone, where response is generally poorer than that for children with growth hormone deficiency, because the variety of diagnoses may have varying growth hormone sensitivity. A firm diagnosis has heuristic value: to truncate further diagnostic evaluation, alert the clinician to other possible comorbidities, inform the family for genetic counseling, and direct appropriate targeted therapy, if available.

Refined preferences of prioritizers improve intelligent diagnosis for Mendelian diseases

Phenotype-guided gene prioritizers have proved a highly efficient approach to identifying causal genes for Mendelian diseases. In our previous study, we preliminarily evaluated the performance of ten prioritizers. However, all the selected software was run based on default settings and singleton mode. With a large-scale family dataset from Deciphering Developmental Disorders (DDD) project (N = 305) and an in-house trio cohort (N = 152), the four optimal performers in our prior study including Exomiser, PhenIX, AMELIE, and LIRCIAL were further assessed through parameter optimization and/or the utilization of trio mode. The in-depth assessment revealed high diagnostic yields of the four prioritizers with refined preferences, each alone or together: (1) 83.3-91.8% of the causal genes were presented among the first ten candidates in the final ranking lists of the four tools; (2) Over 97.7% of the causal genes were successfully captured within the top 50 by either of the four software. Exomiser did best in directly hitting the target (ranking the causal gene at the very top) while LIRICAL displayed a predominant overall detection capability. Besides, cases affected by low-penetrance and high-frequency pathogenic variants were found misjudged during the automated prioritization process. The discovery of the limitations shed light on the specific directions of future enhancement for causal-gene ranking tools.

Should secondary pharmacogenomic variants be actively screened and reported when diagnostic genome-wide sequencing is performed in a child?

This white paper was prepared by the Global Alliance for Genomics and Health Regulatory and Ethics Work Stream's Pediatric Task Team to review and provide perspective with respect to ethical, legal, and social issues regarding the return of secondary pharmacogenomic variants in children who have a serious disease or developmental disorder and are undergoing exome or genome sequencing to identify a genetic cause of their condition. We discuss actively searching for and reporting pharmacogenetic/genomic variants in pediatric patients, different methods of returning secondary pharmacogenomic findings to the patient/parents and/or treating clinicians, maintaining these data in the patient's health record over time, decision supports to assist using pharmacogenetic results in future treatment decisions, and sharing information in public databases to improve the clinical interpretation of pharmacogenetic variants identified in other children. We conclude by presenting a series of points to consider for clinicians and policymakers regarding whether, and under what circumstances, routine screening and return of pharmacogenomic variants unrelated to the indications for testing is appropriate in children who are undergoing genome-wide sequencing to assist in the diagnosis of a suspected genetic disease.

Genetic counselling considerations with genetic/genomic testing in Neonatal and Pediatric Intensive Care Units: A scoping review

Genetic and genomic technologies can effectively diagnose numerous genetic disorders. Patients benefit when genetic counselling accompanies genetic testing and international guidelines recommend pre- and post-test genetic counselling with genome-wide sequencing. However, there is a gap in knowledge regarding the unique genetic counselling considerations with different types of genetic testing in the Neonatal Intensive Care Unit (NICU) and the Pediatric Intensive Care Unit (PICU). This scoping review was conducted to identify the gaps in care with respect to genetic counselling for infants/pediatric patients undergoing genetic and genomic testing in NICUs and PICUs and understand areas in need of improvement in order to optimize clinical care for patients, caregivers, and healthcare providers. Five databases (MEDLINE [Ovid], Embase [Ovid], PsycINFO [Ebsco], CENTRAL [Ovid], and CINHAL [Ebsco]) and grey literature were searched. A total of 170 studies were included and used for data extraction and analysis. This scoping review includes descriptive analysis, followed by a narrative account of the extracted data. Results were divided into three groups: pre-test, post-test, and comprehensive (both pre- and post-test) genetic counselling considerations based on indication for testing. More studies were conducted in the NICU than the PICU. Comprehensive genetic counselling was discussed in only 31% of all the included studies demonstrating the need for both pre-test and post-test genetic counselling for different clinical indications in addition to the need to account for different cultural aspects based on ethnicity and geographic factors.

The Lived Experience of Pediatric Gene Therapy: A Scoping Review

Little is known about patients' and families' lived experiences of participating in pediatric gene therapy (GT) clinical trials. Currently, pediatric GT research targets a broad range of indications--including rare and ultra-rare diseases--which vary in severity and in the availability of alternative therapies. Pediatric GT differs meaningfully from adult GT because the decision to participate involves a dyad of both the child and parent or caregiver/s. It is critical to understand patients' and caregivers' perceptions and experiences of social, emotional, physical, and logistical burdens or benefits of participating in such trials, and how they weigh and prioritize these factors when deciding whether to participate. We conducted a scoping review of the current literature in this subject area with objectives to (1) provide an overview of existing literature, (2) identify gaps and areas for further research, and (3) better understand the lived impact of pediatric GT research on patients and their parents/caregivers. Four themes emerged, including (1) weighing risks and benefits (2) timing of GT trial participation, (3) value of clear communication, and (4) potential impact on quality of life. Notably, our sample surfaced articles about how patients/parents/caregivers were thinking about GT-their understanding of its safety, efficacy, and risks-rather than accounts of their experiences, which was our initial intention. Nevertheless, our findings offer useful insights to improve the informed consent process and promote a more patient- and family-centered approach. Moreover, our findings can contribute to patient advocacy organizations' efforts to develop educational materials tailored to patients' and families' expressed informational needs and perspectives, and can inform more patient- and family-centered policies from GT clinical trial sponsors.

Drosophila CASK regulates brain size and neuronal morphogenesis, providing a genetic model of postnatal microcephaly suitable for drug discovery

BACKGROUND

CASK-related neurodevelopmental disorders are untreatable. Affected children show variable severity, with microcephaly, intellectual disability (ID), and short stature as common features. X-linked human CASK shows dosage sensitivity with haploinsufficiency in females. CASK protein has multiple domains, binding partners, and proposed functions at synapses and in the nucleus. Human and Drosophila CASK show high amino-acid-sequence similarity in all functional domains. Flies homozygous for a hypomorphic CASK mutation (∆18) have motor and cognitive deficits. A Drosophila genetic model of CASK-related disorders could have great scientific and translational value.

METHODS

We assessed the effects of CASK loss of function on morphological phenotypes in Drosophila using established genetic, histological, and primary neuronal culture approaches. NeuronMetrics software was used to quantify neurite-arbor morphology. Standard nonparametric statistics methods were supplemented by linear mixed effects modeling in some cases. Microfluidic devices of varied dimensions were fabricated and numerous fluid-flow parameters were used to induce oscillatory stress fields on CNS tissue. Dissociation into viable neurons and neurite outgrowth in vitro were assessed.

RESULTS

We demonstrated that ∆18 homozygous flies have small brains, small heads, and short bodies. When neurons from developing CASK-mutant CNS were cultured in vitro, they grew small neurite arbors with a distinctive, quantifiable "bushy" morphology that was significantly rescued by transgenic CASK+. As in humans, the bushy phenotype showed dosage-sensitive severity. To overcome the limitations of manual tissue trituration for neuronal culture, we optimized the design and operation of a microfluidic system for standardized, automated dissociation of CNS tissue into individual viable neurons. Neurons from CASK-mutant CNS dissociated in the microfluidic system recapitulate the bushy morphology. Moreover, for any given genotype, device-dissociated neurons grew larger arbors than did manually dissociated neurons. This automated dissociation method is also effective for rodent CNS.

CONCLUSIONS

These biological and engineering advances set the stage for drug discovery using the Drosophila model of CASK-related disorders. The bushy phenotype provides a cell-based assay for compound screening. Nearly a dozen genes encoding CASK-binding proteins or transcriptional targets also have brain-development mutant phenotypes, including ID. Hence, drugs that improve CASK phenotypes might also benefit children with disorders due to mutant CASK partners.

A de novo heterozygous variant in ACOX1 gene cause Mitchell syndrome: the first case in China and literature review

BACKGROUND

Mitchell syndrome (MITCH) is a rare autosomal dominant hereditary disorder, characterized by episodic demyelination, sensorimotor polyneuropathy and hearing loss. MITCH is caused by heterozygous mutation in the ACOX1 gene, which encodes straight-chain acyl-CoA oxidase, on chromosome 17q25.1.  Only 5 unrelated patients have been reported so far, and no reports from China. Here, we describe the first MITCH case in a Chinese individual.

CASE PRESENTATION

A 7-year-old girl initially presented with diffuse desquamatory rash at age 3. Her clinical symptoms in order of presentation were diffuse desquamatory rash, gait instability, ptosis with photophobia, hearing loss, abdominal pain, diarrhea, nausea, and dysuria. Genetic analysis demonstrated that the patient carried a heterozygous variant c.710A>G(p.Asp237Ser) in the ACOX1 gene, which can cause MITCH symptoms. This is the first MITCH case with gastrointestinal and urinary tract symptoms. After administrating N acetylcysteine amide (NACA), some symptoms were relieved and the patient's condition improved.

CONCLUSION

This is the first MITCH case in the Chinese population, and we expanded the genotype spectrum of it. The p.Asp237Ser may be a mutational hotspot in ACOX1 regardless of race. In terms of diagnosis, patients with recurrent rash, gait instability, and hearing loss with some autonomic symptoms should raise the suspicion of MITCH and proper and prompt treatment should be given.

The importance of on-site genetic counseling for prospective assisted reproductive technology patients

PURPOSE

To assess the value of having an onsite genetic counseling service integrated into an assisted reproductive technology (ART) center.

METHODS

Since January 2021, we have offered genetic counseling at our ART center for couples whose medical history suggests risk of transmission of a genetic disorder. The percentage of couples referred for genetic counseling, the distribution of couples according to reasons for consultation, the mode of transmission in cases of Mendelian disorders, and the frequency of mutations for those with identified genetic disorders were determined.

RESULTS

In an 18-month period, 150 of 1340 couples (11.2%) enrolled for ART treatment were referred to the genetic counseling unit. Two-thirds (99/150, 66.0%) were referred for a known genetic risk, a family history of a genetic disorder or chromosomal abnormality, a serious condition of unknown cause, or consanguinity. The remaining couples had a putative genetic risk (diminished ovarian reserve, high incidence of oocyte immaturity, recurrent abortion, or severe male infertility). Of the 99 with known genetic risk, 62 (62.7%), were approved for ART treatment, 23 (23.2%) were recommended prenatal or preimplantation testing, and 14 (14.1%) were referred for further testing before undergoing ART.

CONCLUSIONS

Our findings reveal great value in having an on-site genetic counseling unit for referral of ART patients. Such a unit makes the ART process smoother and safer for couples, and it lightens the burden of ART staff by removing responsibilities for which they are neither trained, nor should they have to assume.

Intensive Care Clinicians' Perspectives on Ethical Challenges Raised by Rapid Genomic Testing in Critically Ill Infants

Rapid genomic testing (rGT) enables genomic information to be available in a matter of hours, allowing it to be used in time-critical settings, such as intensive care units. Although rGT has been shown to improve diagnostic rates in a cost-effective manner, it raises ethical questions around a range of different areas, including obtaining consent and clinical decision-making. While some research has examined the perspectives of parents and genetics health professionals, the attitudes of intensive care clinicians remain under-explored. To address this gap, we administered an online survey to English-speaking neonatal/paediatric intensivists in Europe, Australasia and North America. We posed two ethical scenarios: one relating to obtaining consent from the parents and the second assessing decision-making regarding the provision of life-sustaining treatments. Descriptive statistics were used to analyse the data. We received 40 responses from 12 countries. About 50-75% of intensivists felt that explicit parental consent was necessary for rGT. About 68-95% felt that a diagnosis from rGT should affect the provision of life-sustaining care. Results were mediated by intensivists' level of experience. Our findings show divergent attitudes toward ethical issues generated by rGT among intensivists and suggest the need for guidance regarding ethical decision-making for rGT.

Successful Treatment of a Rare Cholesterol Homeostasis Disorder Due to CYP27A1 Gene Mutation with Chenodeoxycholic Acid Therapy

Cerebrotendinous xanthomatosis (CTX) is a genetic disorder of the cholesterol metabolic pathway, most often associated with variants in the CYP27A1 gene. The dysregulation of cholesterol metabolism results in the accumulation of metabolites such as cholestanol, which has a predilection for neuronal tissue and tendons. The condition is treatable with chenodeoxycholic acid (CDCA), which halts the production of these metabolites. We present two adult brothers, without diagnosis, suffering from ataxia, general muscle weakness and cognitive deficits. Both brothers suffered from early onset cataracts, watery stools and thoracic kyphoscoliosis. Magnetic resonance imaging revealed hyperintense alterations in the central nervous system and intratendinous xanthomas in the Achilles tendons. A biochemical analysis showed elevated levels of cholestanol, lathosterol and 7-dehydrocholesterol. Their family history was negative for neurological and metabolic disorders. Genetic testing revealed a pathogenic CYP27A1 variant (c.1184+1G>A) in both brothers, confirming the diagnosis. The patients were started on CDCA therapy and have shown significant improvement at their follow-up examinations. Early diagnosis and treatment initiation in CTX patients is of great importance, as the significant reversal of disease progression can be achieved. For this reason, clinical genetic testing is necessary when it comes to patients with an onset of cataracts, chronic diarrhea, and neurological symptoms in early childhood.

The impact of caregiving for children with chronic conditions on the HPA axis: A scoping review

Caregiving has been robustly linked to caregiver health through the dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis in the context of caregiving for an adult with a chronic illness. However, little research examines the physiological impact of caregiving for a child with a chronic illness despite high burden and unique stressors. In this review, we explore the links of caregiving for a child with a congenital, chromosomal, or genetic disorder to the regulation or dysregulation of the HPA axis. A search was conducted in PubMed, Embase, and the Web of Science and 15 studies met inclusion criteria. Overall, there were inconsistent links of caregiving to HPA axis functioning, perhaps due to the heterogeneity across disease contexts, study designs, and biomarker measurement. Future research should standardize measurement and study designs, increase participant diversity, and examine moderators of the links of caregiving to the HPA axis.

Identification of Novel Mutations in the MMAA and MUT Genes among Methylmalonic Aciduria Families

Background

Methylmalonic aciduria is a rare inherited metabolic disorder with autosomal recessive inheritance pattern. There are still MMA patients without known mutations in the responsible genes. This study aimed to identify mutations in Iranian MMA families using autozygosity mapping and NGS.

Methods

Multiplex PCR was performed on DNAs isolated from 12 unrelated MMA patients and their family members using 19 STR markers flanking MUT, MMAA, and MMAB genes, followed by Sanger sequencing. WES was carried out in the patients with no mutation.

Results

Haplotype analysis and Sanger sequencing revealed two novel, mutations, A252Vf*5 and G87R, within the MMAA and MUT genes, respectively. Three patients showed no mutations in either autozygosity mapping or NGS analysis.

Conclusion

High-frequency mutations within exons 2 and 3 of MUT gene and exon 7 of MMAB gene are consistent with the global expected frequency of genetic variations among MMA patients.

The Utility of Small Fishes for the Genetic Study of Human Age-Related Disorders

Animal models have been used to model human diseases, and among them, small fishes have been highlighted for their usefulness in various ways, such as the low cost of maintenance, ease of genetic modification, small size for easy handling, and strength in imaging studies due to their relative transparency. Recently, the use of turquoise killifish, Nothobranchius furzeri, which is known to exhibit various aging phenotypes in a short period, has attracted attention in research on aging and age-related diseases. However, when using animal models, it is important to keep their genetic background and interspecies differences in mind for translating them into human diseases. In this article, we obtained the gene symbols of protein-coding genes of turquoise killifish, medaka, zebrafish, and humans from NCBI datasets and extracted common shared genes among four species to explore the potential of interspecies translational research and to apply small fish models for human age-related disorders. Common shared protein-coding genes were analyzed with the Reactome Pathway Database to determine the coverage of these genes in each pathway in humans. We applied common shared genes to the Orphanet database to establish a list of human diseases that contain common shared genes among the four species. As examples, the senescence-related pathways and some pathways of human age-related diseases, such as Alzheimer’s disease, Parkinson’s disease, frontotemporal dementia, nonalcoholic fatty liver disease, progeria, hepatocellular carcinoma, and renal cell carcinoma, were extracted from the curated pathway and disease list to discuss the further utility of fish models for human age-related disorders.

'Diagnostic shock': the impact of results from ultrarapid genomic sequencing of critically unwell children on aspects of family functioning

Rapid genomic sequencing (rGS) is being increasingly used in neonatal and paediatric intensive care units. While there is emerging evidence of clinical utility and cost-effectiveness, concerns have been raised regarding the impact of delivering genomic results in an acute care setting. To help investigate these concerns, we analysed survey data collected from caregivers whose children had received rGS through a national rapid genomic diagnosis program. The impact of rGS on families was assessed through the PedsQL2.0 Family Impact Module and the State-Trait Anxiety Inventory (STAI-6). Sixty-one parents/carers completed the survey during the study period (response rate 48%; 61/128). Mean parent and family functioning was reduced in this sample, reflecting the stressful conditions facing families with critically unwell children. We found caregivers whose children had received a diagnostic result through rGS reported a reduced family relationships score compared to caregivers of children who did not receive a diagnosis. These findings have implications for genetic counselling practice in this setting.

Identification of a Novel Deep Intronic Variant by Whole Genome Sequencing Combined With RNA Sequencing in a Chinese Patient With Menkes Disease

Background: Menkes disease (MD) is a rare X-linked connective tissue disorder of copper metabolism caused by pathogenic variant(s) in ATP7A gene. The aim of the present study is to determine the clinical characteristics and molecular basis of one patient with MD.

Methods: One 10-month-old Chinese boy who met the clinical manifestations of MD was enrolled in this study. Whole genome sequencing (WGS) was performed in the patient in order to identify the variant(s), followed by Sanger sequencing. RNA sequencing (RNA-seq) from whole blood was subsequently applied to assess the effect of variant on transcription levels, and reverse transcriptase-polymerase chain reaction (RT-PCR) was performed for further validation. In addition, X chromosome inactivation (XCI) status of the patient’s mother at the DNA level was measured by capillary electrophoresis.

Results: The patient suffered from intermittent convulsions for more than 6 months, with psychomoto retardation and neurodegenerations. The patient also had curly hair, hypopigmented skin, cutis laxa, decreased muscle strength and hypotonia. MRI showed the intracranial arteries were tortuous with some “spiral” changes. The patient’s serum ceruloplasmin level was low. WGS revealed one novel hemizygous variant, c.2627-501C > T (NM_000,052.7), located in the deep intronic sequence of ATP7A gene. Sanger sequencing confirmed that the variant was inherited from his mother. RNA-seq confirmed the variant itself, and identified a pseudo-exon inserted between exons 12 and 13 in mRNA of ATP7A. The sequencing results of RT-PCR from the patient confirmed this finding, while neither of his parents detected aberrant splicing. The Capillary electrophoresis results showed that the patient’s mother had a skewed XCI.

Conclusion: Our finding of the variant enlarges the variant spectrum in the ATP7A gene. This is a novel deep intronic variant which leads to the activation of a pseudo-exons in the ATP7A gene, and it demonstrates the usefulness of WGS combined with RNA-seq, in terms of revealing disease-causing variants in non-coding regions. Furthermore, the fact that the deep intronic variants cause disease by the activation of pseudo-exon inclusion indicates that in MD this might be an important mechanism.

Current Status of Genetic Counselling for Rare Diseases in Spain

Genetic Counselling is essential for providing personalised information and support to patients with Rare Diseases (RD). Unlike most other developed countries, Spain does not recognize geneticists or genetic counsellors as healthcare professionals Thus, patients with RD face not only challenges associated with their own disease but also deal with lack of knowledge, uncertainty, and other psychosocial issues arising as a consequence of diagnostic delay. In this review, we highlight the importance of genetic counsellors in the field of RD as well as evaluate the current situation in which rare disease patients receive genetic services in Spain. We describe the main units and strategies at the national level assisting patients with RD and we conclude with a series of future perspectives and unmet needs that Spain should overcome to improve the management of patients with RD.

Bridging the Gap between Scientific Advancement and Real-World Application: Pediatric Genetic Counseling for Common Syndromes and Single-Gene Disorders

Screening and diagnostic testing for single-gene disorders and common syndromes in the pediatric setting frequently generate data that are challenging to interpret, and the ability to diagnose genetic conditions has outpaced the development of successful treatments or cures. Genetic testing is now integrated purposefully into a variety of primary and specialty care clinics, creating an increased requirement for genetic literacy among providers and patients, as well as a growing need to incorporate genetic counseling services into mainstream clinical practice. The practice of pediatric genetic counseling encompasses a unique combination of skills and training designed to address the evolving psychological, social, educational, medical, and reproductive concerns of patients and their families, which complements the multidisciplinary services of physicians, nurses, and other allied health professionals caring for patients with pediatric-onset genetic conditions. The potential range of genetic counseling needs in the pediatric setting transcends the diagnostic period. The sustained nature of pediatric care presents opportunities for development of trusting and longstanding professional relationships that permit the evolving genetic counseling needs of patients and families to be met. A discussion of cystic fibrosis, a common autosomal recessive single-gene disorder with an increasingly broad clinical spectrum and genotype-phenotype variability, serves as a useful case study to illustrate the current and emerging genetic counseling practices, goals, and challenges impacting patients and their families.

Rapid prenatal diagnosis of skeletal dysplasia using medical trio exome sequencing: Benefit for prenatal counseling and pregnancy management

OBJECTIVE

The aim of this study is to explore the utility of rapid medical trio exome sequencing (ES) for prenatal diagnosis using the skeletal dysplasia as an exemplar.

METHOD

Pregnant women who were referred for genetic testing because of ultrasound detection of fetal abnormalities suggestive of a skeletal dysplasia were identified prospectively. Fetal samples (amniocytes or cord blood), along with parental blood, were send for rapid copy number variations testing and medical trio ES in parallel.

RESULTS

Definitive molecular diagnosis was made in 24/27 (88.9%) cases. Chromosomal abnormality (partial trisomy 18) was detected in one case. Sequencing results had explained the prenatal phenotype enabling definitive diagnoses to be made in 23 cases. There were 16 de novo dominant pathogenic variants, four dominant pathogenic variants inherited maternally or paternally, two recessive conditions with pathogenic variants inherited from unaffected parents, and one X-linked condition. The turnaround time from receipt of samples in the laboratory to reporting sequencing results was within 2 weeks.

CONCLUSION

Medical trio ES can yield very timely and high diagnostic rates in fetuses presenting with suspected skeletal dysplasia. These definite diagnoses aided parental counseling and decision making in most of cases.