Next-generation community genetics for low- and middle-income countries

The cost of genetic diagnosis of suspected hereditary pediatric cataracts with whole-exome sequencing from a middle-income country perspective: a mixed costing analysis

Up to 25% of pediatric cataract cases are inherited. There is sparse information in the literature regarding the cost of whole-exome sequencing (WES) for suspected hereditary pediatric cataracts. Molecular diagnosis of suspected hereditary pediatric cataracts is important for comprehensive genetic counseling. We performed a partial economic evaluation with a mixed costing analysis, using reimbursement data and microcosting approach with a bottom-up technique to estimate the cost of using WES for genetic diagnosis of suspected hereditary pediatric cataracts from the perspective of the Brazilian governmental health care system. One hundred and ten participants from twenty-nine families in Rio de Janeiro (RJ) were included. Costs of consumables, staff and equipment were calculated. Two scenarios were created: (1) The reference scenario included patients from RJ with suspected hereditary pediatric cataracts plus two family members. (2) The alternative scenario considered other genetic diseases, resulting in 5,280 exams per month. Sensitivity analysis was also performed. In the reference scenario, the total cost per exam was 700.09 United States dollars (USD), and in the alternative scenario, the total cost was 559.23 USD. The cost of WES alone was 527.85 USD in the reference scenario and 386.98 USD in the alternative scenario. Sensitivity analysis revealed that the largest costs were associated with consumables in both scenarios. Economic evaluations can help inform policy decisions, especially in middle-income countries such as Brazil.

Utility of next generation sequencing in paediatric neurological disorders: experience from South Africa

Next generation sequencing (NGS)-based tests have become routine first-line investigative modalities in paediatric neurology clinics in many high-income countries (HICs). Studies from these countries show that these tests are both cost-effective and reliable in diagnosing many complex childhood neurological diseases. However, NGS-based testing in low-and middle-income countries (LMICs) is limited due to affordability constraints. The primary objective of this study was to evaluate the diagnostic yield and impact of targeted gene panel sequencing in a selected paediatric cohort attending a tertiary paediatric neurology clinic in the Western Cape Province of South Africa. This retrospective study included 124 consecutive paediatric patients with neurological disease, aged 6 weeks to 17 years, referred for NGS-based multi-gene panel testing over a 41-month period. Twenty-four different disease group-specific panels were utilized. A caregiver experience questionnaire was administered when a pathogenic variant was identified. The overall study diagnostic yield (DY) was 45% (56/124 patients). The diagnostic yield in this study is similar to previously reported paediatric cohorts in HICs. The high yields for neuromuscular disorders (52%) and early epileptic encephalopathies (41%) suggest that NGS-based panels may be more cost-effective as first-line testing in well-defined phenotypes. The latter finding argues for early inclusion of all children with developmental epileptic encephalopathies (DEE), as early diagnosis leads to better treatment and avoidance of unnecessary investigations.

Diagnostic delay in monogenic disease: A scoping review

PURPOSE

Diagnostic delay in monogenic disease is reportedly common. We conducted a scoping review investigating variability in study design, results, and conclusions.

METHODS

We searched the academic literature on January 17, 2023, for original peer reviewed journals and conference articles that quantified diagnostic delay in monogenic disease. We abstracted the reported diagnostic delay, relevant study design features, and definitions.

RESULTS

Our search identified 259 articles quantifying diagnostic delay in 111 distinct monogenetic diseases. Median reported diagnostic delay for all studies collectively in monogenetic diseases was 5.0 years (IQR 2-10). There was major variation in the reported delay within individual monogenetic diseases. Shorter delay was associated with disorders of childhood metabolism, immunity, and development. The majority (67.6%) of articles that studied delay reported an improvement with calendar time. Study design and definitions of delay were highly heterogenous. Three gaps were identified: (1) no studies were conducted in the least developed countries, (2) delay has not been studied for the majority of known, or (3) most prevalent genetic diseases.

CONCLUSION

Heterogenous study design and definitions of diagnostic delay inhibit comparison across studies. Future efforts should focus on standardizing delay measurements, while expanding the research to low-income countries.

Rapid genomic sequencing for genetic disease diagnosis and therapy in intensive care units: a review

Single locus (Mendelian) diseases are a leading cause of childhood hospitalization, intensive care unit (ICU) admission, mortality, and healthcare cost. Rapid genome sequencing (RGS), ultra-rapid genome sequencing (URGS), and rapid exome sequencing (RES) are diagnostic tests for genetic diseases for ICU patients. In 44 studies of children in ICUs with diseases of unknown etiology, 37% received a genetic diagnosis, 26% had consequent changes in management, and net healthcare costs were reduced by $14,265 per child tested by URGS, RGS, or RES. URGS outperformed RGS and RES with faster time to diagnosis, and higher rate of diagnosis and clinical utility. Diagnostic and clinical outcomes will improve as methods evolve, costs decrease, and testing is implemented within precision medicine delivery systems attuned to ICU needs. URGS, RGS, and RES are currently performed in <5% of the ~200,000 children likely to benefit annually due to lack of payor coverage, inadequate reimbursement, hospital policies, hospitalist unfamiliarity, under-recognition of possible genetic diseases, and current formatting as tests rather than as a rapid precision medicine delivery system. The gap between actual and optimal outcomes in children in ICUs is currently increasing since expanded use of URGS, RGS, and RES lags growth in those likely to benefit through new therapies. There is sufficient evidence to conclude that URGS, RGS, or RES should be considered in all children with diseases of uncertain etiology at ICU admission. Minimally, diagnostic URGS, RGS, or RES should be ordered early during admissions of critically ill infants and children with suspected genetic diseases.

Perceptions and beliefs of community gatekeepers about genomic risk information in African cleft research

BACKGROUND

A fundamental ethical issue in African genomics research is how socio-cultural factors impact perspectives, acceptance, and utility of genomic information, especially in stigmatizing conditions like orofacial clefts (OFCs). Previous research has shown that gatekeepers (e.g., religious, political, family or community leaders) wield considerable influence on the decision-making capabilities of their members, including health issues. Thus, their perspectives can inform the design of engagement strategies and increase exposure to the benefits of genomics testing/research. This is especially important for Africans underrepresented in genomic research. Our study aims to investigate the perspectives of gatekeepers concerning genomic risk information (GRI) in the presence of OFCs in a sub-Saharan African cohort.

METHODS

Twenty-five focus group discussions (FGDs) consisting of 214 gatekeepers (religious, community, ethnic leaders, and traditional birth attendants) in Lagos, Nigeria, explored the opinions of participants on genomic risk information (GRI), OFC experience, and the possibility of involvement in collaborative decision-making in Lagos, Nigeria. Transcripts generated from audio recordings were coded and analyzed in NVivo using thematic analysis.

RESULTS

Three main themes-knowledge, beliefs, and willingness to act-emerged from exploring the perspective of gatekeepers about GRI in this group. We observed mixed opinions regarding the acceptance of GRI. Many participants believed their role is to guide and support members when they receive results; this is based on the level of trust their members have in them. However, participants felt they would need to be trained by medical experts to do this. Also, religious and cultural beliefs were crucial to determining participants' understanding of OFCs and the acceptance and utilization of GRI.

CONCLUSIONS

Incorporating cultural sensitivity into public engagement could help develop appropriate strategies to manage conflicting ideologies surrounding genomic information in African communities. This will allow for more widespread access to the advances in genomics research in underrepresented populations. We also recommend a synergistic relationship between community health specialists/scientists, and community leaders, including spiritual providers to better understand and utilize GRI.

A feasible molecular diagnostic strategy for rare genetic disorders within resource-constrained environments

Timely and accurate diagnosis of rare genetic disorders is critical, as it enables improved patient management and prognosis. In a resource-constrained environment such as the South African State healthcare system, the challenge is to design appropriate and cost-effective assays that will enable accurate genetic diagnostic services in patients of African ancestry across a broad disease spectrum. Next-generation sequencing (NGS) has transformed testing approaches for many Mendelian disorders, but this technology is still relatively new in our setting and requires cost-effective ways to implement. As a proof of concept, we describe a feasible diagnostic strategy for genetic disorders frequently seen in our genetics clinics (RASopathies, Cornelia de Lange syndrome, Treacher Collins syndrome, and CHARGE syndrome). The custom-designed targeted NGS gene panel enabled concurrent variant screening for these disorders. Samples were batched during sequencing and analyzed selectively based on the clinical phenotype. The strategy employed in the current study was cost-effective, with sequencing and analysis done at USD849.68 per sample and achieving an overall detection rate of 54.5%. The strategy employed is cost-effective as it allows batching of samples from patients with different diseases in a single run, an approach that can be utilized with rare and less frequently ordered molecular diagnostic tests. The subsequent selective analysis pipeline allowed for timeous reporting back of patients results. This is feasible with a reasonable yield and can be employed for the molecular diagnosis of a wide range of rare monogenic disorders in a resource-constrained environment.

The impact of applying various de novo assembly and correction tools on the identification of genome characterization, drug resistance, and virulence factors of clinical isolates using ONT sequencing

Oxford Nanopore sequencing technology (ONT) is currently widely used due to its affordability, simplicity, and reliability. Despite the advantage ONT has over next-generation sequencing in detecting resistance genes in mobile genetic elements, its relatively high error rate (10-15%) is still a deterrent. Several bioinformatic tools are freely available for raw data processing and obtaining complete and more accurate genome assemblies. In this study, we evaluated the impact of using mix-and-matched read assembly (Flye, Canu, Wtdbg2, and NECAT) and read correction (Medaka, NextPolish, and Racon) tools in generating complete and accurate genome assemblies, and downstream genomic analysis of nine clinical Escherichia coli isolates. Flye and Canu assemblers were the most robust in genome assembly, and Medaka and Racon correction tools significantly improved assembly parameters. Flye functioned well in pan-genome analysis, while Medaka increased the number of core genes detected. Flye, Canu, and NECAT assembler functioned well in detecting antimicrobial resistance genes (AMR), while Wtdbg2 required correction tools for better detection. Flye was the best assembler for detecting and locating both virulence and AMR genes (i.e., chromosomal vs. plasmid). This study provides insight into the performance of several read assembly and read correction tools for analyzing ONT sequencing reads for clinical isolates.

Diagnostic yield of pediatric and prenatal exome sequencing in a diverse population

The diagnostic yield of exome sequencing (ES) has primarily been evaluated in individuals of European ancestry, with less focus on underrepresented minority (URM) and underserved (US) patients. We evaluated the diagnostic yield of ES in a cohort of predominantly US and URM pediatric and prenatal patients suspected to have a genetic disorder. Eligible pediatric patients had multiple congenital anomalies and/or neurocognitive disabilities and prenatal patients had one or more structural anomalies, disorders of fetal growth, or fetal effusions. URM and US patients were prioritized for enrollment and underwent ES at a single academic center. We identified definitive positive or probable positive results in 201/845 (23.8%) patients, with a significantly higher diagnostic rate in pediatric (26.7%) compared to prenatal patients (19.0%) (P = 0.01). For both pediatric and prenatal patients, the diagnostic yield and frequency of inconclusive findings did not differ significantly between URM and non-URM patients or between patients with US status and those without US status. Our results demonstrate a similar diagnostic yield of ES between prenatal and pediatric URM/US patients and non-URM/US patients for positive and inconclusive results. These data support the use of ES to identify clinically relevant variants in patients from diverse populations.

Clinical and Regulatory Challenges and Opportunities for Monoclonal Antibodies in Low- and Middle-Income Countries: Lessons from COVID-19 and Beyond

Monoclonal antibodies are an effective and growing class of pharmaceuticals for the treatment and prevention of a broad range of non-communicable and infectious diseases; however, most low- and middle-income countries have limited access to these innovative products. Many factors contribute to the global inequity of access to these products; however, in this report, we focus on clinical and regulatory complexities as further highlighted by the coronavirus disease 2019 pandemic. Despite a higher prevalence of many diseases in low- and middle-income countries, only 12% of clinical trials for monoclonal antibodies are conducted in these countries. Additionally, only a fraction of the available monoclonal antibodies in the USA and European Union are authorized for use in low- and middle-income countries. Through learnings from desk research and global symposia with international partners, we present recommendations to harmonize processes and facilitate regional and international collaborations for more rapid approval of fit-for-purpose innovative monoclonal antibodies and biosimilars in low- and middle-income countries.

Barriers to genetic testing in clinical psychiatry and ways to overcome them: from clinicians' attitudes to sociocultural differences between patients across the globe

Genetic testing has evolved rapidly over recent years and new developments have the potential to provide insights that could improve the ability to diagnose, treat, and prevent diseases. Information obtained through genetic testing has proven useful in other specialties, such as cardiology and oncology. Nonetheless, a range of barriers impedes techniques, such as whole-exome or whole-genome sequencing, pharmacogenomics, and polygenic risk scoring, from being implemented in psychiatric practice. These barriers may be procedural (e.g., limitations in extrapolating results to the individual level), economic (e.g., perceived relatively elevated costs precluding insurance coverage), or related to clinicians' knowledge, attitudes, and practices (e.g., perceived unfavorable cost-effectiveness, insufficient understanding of probability statistics, and concerns regarding genetic counseling). Additionally, several ethical concerns may arise (e.g., increased stigma and discrimination through exclusion from health insurance). Here, we provide an overview of potential barriers for the implementation of genetic testing in psychiatry, as well as an in-depth discussion of strategies to address these challenges.

T. A genome sequencing system for universal newborn screening, diagnosis, and precision medicine for severe genetic diseases

Newborn screening (NBS) dramatically improves outcomes in severe childhood disorders by treatment before symptom onset. In many genetic diseases, however, outcomes remain poor because NBS has lagged behind drug development. Rapid whole-genome sequencing (rWGS) is attractive for comprehensive NBS because it concomitantly examines almost all genetic diseases and is gaining acceptance for genetic disease diagnosis in ill newborns. We describe prototypic methods for scalable, parentally consented, feedback-informed NBS and diagnosis of genetic diseases by rWGS and virtual, acute management guidance (NBS-rWGS). Using established criteria and the Delphi method, we reviewed 457 genetic diseases for NBS-rWGS, retaining 388 (85%) with effective treatments. Simulated NBS-rWGS in 454,707 UK Biobank subjects with 29,865 pathogenic or likely pathogenic variants associated with 388 disorders had a true negative rate (specificity) of 99.7% following root cause analysis. In 2,208 critically ill children with suspected genetic disorders and 2,168 of their parents, simulated NBS-rWGS for 388 disorders identified 104 (87%) of 119 diagnoses previously made by rWGS and 15 findings not previously reported (NBS-rWGS negative predictive value 99.6%, true positive rate [sensitivity] 88.8%). Retrospective NBS-rWGS diagnosed 15 children with disorders that had been undetected by conventional NBS. In 43 of the 104 children, had NBS-rWGS-based interventions been started on day of life 5, the Delphi consensus was that symptoms could have been avoided completely in seven critically ill children, mostly in 21, and partially in 13. We invite groups worldwide to refine these NBS-rWGS conditions and join us to prospectively examine clinical utility and cost effectiveness.

Healthcare professionals' perceptions of implementing a decision support intervention for cascade screening for beta-thalassemia in Pakistan

Counselling relatives of individuals with βeta-Thalassaemia Major (β-TM) about cascade screening is the role of field officers (FOs) in the Punjab Thalassaemia Prevention Project (PTPP). This paper presents FOs' views about using a 'decision support intervention for relatives' (DeSIRe) to facilitate informed decision making, and their perception of its implementation and sustainability. Semi-structured qualitative interviews were conducted with nine FOs (June to July 2021) in seven cities in the Punjab province (Lahore, Sheikhupura, Nankana Sahab, Kasur, Gujranwala, Multan, and Faisalabad) following its use in routine clinical practice. Thematic analysis shows that the FOs were overwhelmingly supportive of the DeSIRe, expressing enthusiasm and identifying benefits of its use, both for their own practice and for relatives. They supported the aim of the intervention to enable them to facilitate relatives' decision-making about cascade screening, and advocated its use more widely within the PTPP and the other provinces of Pakistan. Overall, the DeSIRe was valued by the FOs for use in routine practice. These findings suggest the DeSIRe is highly likely to be implemented by healthcare professionals more widely in the PTPP and, therefore, is worth evaluating to prove its efficacy. Further research is needed on the extent to which the DeSIRe could be adapted for use by other healthcare professionals with similar responsibilities in the other provinces of Pakistan, and in other low-middle income countries.

"Right diet for the right person": a focus group study of nutritionist-dietitians' perspectives on nutritional genomics and gene-based nutrition advice

Advances in nutritional genomics are intended to revolutionize nutrition practice. A basic understanding of nutritional genomics among nutritionist-dietitians is critical for such advancements to occur. As a precedent to the development and integration of gene-based nutrition advice, this study aimed to assess hospital-based nutritionist-dietitians' perceptions of nutritional genomics. A total of ten focus group discussions (FGDs) with sixty-one registered nutritionist-dietitians (RNDs) from hospitals in the National Capital Region (NCR), Philippines, were conducted from October to November 2019. Data were collected using a pretested semistructured discussion guide, and thematic analysis was subsequently performed. Diverging perceptions about nutritional genomics were noted among the FGD participants. Five themes emerged relating to the enablers and barriers of gene-based nutrition advice: training and capacity building, the extent of information to be disclosed, cost, ethical considerations, and government support. Themes related to the desired features of the gene-based nutrition advice included being consent-driven, cost-effective, technology-oriented, and guided by standards. The results of this study suggest that training and continued learning will equip RNDs to provide nutrition advice based on genetic information. However, other factors, such as cost and ethical considerations, are critical dimensions that need to be acknowledged and addressed before integrating gene-based advice into nutrition practice.

CFTR mutational screening by next-generation sequencing reveals novel variants and a high carrier rate in a Middle Eastern population

Cystic fibrosis is the most common life-limiting autosomal recessive disease in western countries with an incidence of 1:2500 in United States and 1:1000 in some European countries. Similar incidences were noted for the Middle East with variations from 1 in 2560 to 1 in 15,876 according to the degree of consanguinity. This is a preliminary systematic study that aims to assess the incidence and carrier rate of cystic fibrosis in the Middle Eastern Lebanese population; known for a high frequency of consanguinity. One hundred thirteen DNA samples were collected from neonatal blood cards obtained from newborns to healthy unrelated families with no previous history of Cystic fibrosis. Screening for Cystic Fibrosis-causing pathogenic variants was performed using next generation sequencing, and 17 different single nucleotide variants were detected, including six pathogenic and likely pathogenic. 5.5%-7% newborns were found to be carriers of a variant strongly suggestive of pathogenicity and comparable to published literature worldwide. This pilot analysis highlights the challenging interpretation of CFTR variants in a country underrepresented by large ethnic population analyses, and stresses the importance of premarital screening programs for Cystic fibrosis.

Cost-Effectiveness of Targeted Exome Analysis as a Diagnostic Test in Glomerular Diseases

BACKGROUND

Despite the emergence of diagnostic and clinical utility evidence in nephrology, publicly funded access to genomic testing is restricted in most health care systems. To establish genomic sequencing as a clinical test, an evaluation of cost-effectiveness is urgently required.

METHODS

An economic evaluation, informed by a primary clinical study and available clinical evidence and guidelines in nephrology, was performed to evaluate the cost-effectiveness and optimal timing of exome sequencing (ES) in adults and children with suspected monogenic glomerular diseases compared with nongenomic investigations (NGIs). Six diagnostic strategies reflecting current practice and recommended models of care in Australia were modeled: (i) NGIs, (ii) late gene panel followed by ES, (iii) late ES, (iv) early gene panel, (v) early gene panel followed by ES, and (vi) early ES.

RESULTS

ES with targeted analysis achieved a diagnosis in 23 of 63 (36.5%) adults and 10 of 24 (41.6%) children. NGIs were estimated to diagnose 4.0% of children, with an average estimated cost of AU$6120 per child. Integrating ES as a first-line test in children was cost saving, with an incremental cost saving of AU$3230 per additional diagnosis compared with NGIs. In adults, NGIs was estimated to diagnose 8% of patients, with an average estimated cost of AU$1830 per person. In adults, integrating ES early resulted in an incremental cost per additional diagnosis of AU$5460 relative to NGIs.

CONCLUSIONS

Early ES with targeted analysis was effective for diagnosing monogenic kidney disease, with substantial cost savings in children.

The introduction of genetic counseling in Ethiopia: Results of a training workshop and lessons learned

BACKGROUND

Over the past two decades non-communicable diseases (NCDs) have steadily increased as a cause of worldwide disability and mortality with a concomitant decrease in disease burden from communicable, maternal, neonatal and nutritional conditions. Congenital anomalies, the most common NCD affecting children, have recently become the fifth leading cause of under-five mortality worldwide, ahead of other conditions such as malaria, neonatal sepsis and malnutrition. Genetic counseling has been shown to be an effective method to decrease the impact of congenital anomalies and genetic conditions but is absent in almost all sub-Saharan Africa countries. To address this need for counseling services we designed and implemented the first broad-based genetic counseling curriculum in Ethiopia, launching it at St. Paul's Millennium Medical College (SPHMMC) in Addis Ababa, Ethiopia.

METHODS

The curriculum, created by Michigan Medicine and SPHMMC specialists, consisted of medical knowledge and genetic counseling content and was delivered to two cohorts of nurses. Curriculum evaluation consisted of satisfaction surveys and pre- and post-assessments covering medical knowledge and genetic counseling content. Following Cohort 1 training, the curriculum was modified to increase the medical knowledge material and decrease Western genetic counseling principles material.

RESULTS

Both cohorts reported high levels of satisfaction but felt the workshop was too short. No significant improvements in assessment scores were seen for Cohort 1 in terms of total scores and medical knowledge and genetic counseling-specific questions. Following curriculum modification, improvements were seen in Cohort 2 with an increase in total assessment scores from 63% to 73% (p = 0.043), with medical knowledge-specific questions increasing from 57% to 79% (p = 0.01) with no significant change in genetic counseling-specific scores. Multiple logistic, financial, cultural and systems-specific barriers were identified with recommendations for their consideration presented.

CONCLUSION

Genetics medical knowledge of Ethiopian nurses increased significantly following curriculum delivery though difficulty was encountered with Western genetic counseling material.

Developmental anomalies and associated impairments in Saudi children with cerebral palsy: a registry-based, multicenter study

Background

There are few epidemiological data to support rehabilitation programs for cerebral palsy (CP). Scarce international studies described the developmental anomalies (DAs) among children with CP. To our knowledge, the Arab countries did not publish data regarding this topic. This study aimed to describe the percentage of DAs among children with CP and detect the association between clinical subtypes and impairment severity in children with various DAs. We collected registry data of 679 children with cerebral palsy, between 2014 and 2019, from Armed Forces Hospitals, Taif, Kingdom of Saudi Arabia (KSA). We recorded demographic, perinatal, postnatal, developmental anomalies, subtypes, and impairment characteristics. We utilized the chi-square test to calculate the differences between groups.

Results

We reported significant differences between the children with and without anomalies regarding the percentages of consanguinity, preterm labor, low birth weight, and neonatal intensive care unit admission (P = 0.001, 0.002, 0.003, 0.005, respectively). Congenital dysplasia of the hip and hydrocephalus was the most frequent skeletal and nervous anomalies among children with DAs (19.1% and 12.8%, respectively). The spastic bilateral pattern was significantly higher among children with skeletal anomalies than the central nervous system/other groups (P < 0.001). The nervous anomalies group had higher frequencies of severe intellectual, motor, speech, and visual disabilities and a higher percentage of seizures than all other groups.

Conclusions

The frequency of children with anomalies in this study was comparable to previous studies. Children with CP and nervous system anomalies had more severe motor disabilities and associated impairments.

Knowledge and attitudes about genetic counseling in patients at a major hospital in Addis Ababa, Ethiopia

Previous work at St. Paul's Hospital Millennium Medical College (SPHMMC) in Addis Ababa, Ethiopia, demonstrated a need for genetic counseling (GC) services, with 4% of pediatric, neonatal intensive care, and prenatal patients identified as having indications for genetic evaluation (Quinonez et al, 2019). The aim of this study was to investigate SPHMMC patients' familiarity with, knowledge of, and attitudes toward GC services. Surveys were adapted from previous work in North America populations (Riesgraf et al, 2015 and Gemmell et al, 2017) and administered to 102 patients, and results were compared to North American populations using Student's t test. 30% of respondents reported at least some familiarity with GC, primarily via the media or healthcare providers. Patients had generally positive attitudes toward GC, reporting they would trust information provided by a genetic counselor and that GC is in line with their values. Knowledge of GC showed similar trends overall when compared to results from North American populations. Our work indicates limited exposure to GC in this population, but generally positive feelings toward GC. Patients' attitudes toward GC were comparable to rural North American populations surveyed using the same tool on most items; however, cultural differences including views on abortions and directiveness of healthcare providers could account for discrepancies and are important considerations when implementing genetic services globally.

Congenital anomalies in children with cerebral palsy in rural Bangladesh

AIM

To determine the proportion of children with cerebral palsy (CP) who had major congenital anomalies, describe the types of disorders, and report on the children's functional outcomes.

METHOD

Data were extracted from the Bangladesh Cerebral Palsy Register (BCPR). Descriptive analyses were conducted on children with CP and major congenital anomalies. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to measure the association between major congenital anomalies, clinical severity, and presence of comorbidities.

RESULTS

Between January 2015 and December 2016, 726 children with CP were newly registered with the BCPR (277 females, 449 males; mean age [SD] at registration 90mo [54mo], 4mo-18y). Seventy-eight children (11%) had a major congenital anomaly. Neurological (86%) and musculoskeletal congenital anomalies (10%) were the most common. Microcephaly was the most common congenital anomaly (83%). The odds of severe functional motor limitations (OR=2.4, 95% CI=1.9-2.9), epilepsy (OR=1.6, 95% CI=1.1-2.1), visual impairment (OR=2.6, 95% CI=2.0-3.2), presence of strabismus (OR=3.9, 95% CI=3.8-4.4), hearing (OR=1.2, 95% CI=0.6-1.9), speech (OR=5.4, 95% CI=4.6-6.2), and intellectual impairments (OR=2.3, 95% CI=1.8-2.8) were higher in children with congenital anomalies compared to children without.

INTERPRETATION

The proportion of children with major congenital anomalies in the BCPR (11%) was lower than that identified in higher-income countries. This may be because of differences in how congenital anomalies are diagnosed as well as the impact of survival bias. In Bangladesh, children with CP and major congenital anomalies are more likely to have severe functional motor limitations and associated comorbidities.

WHAT THIS PAPER ADDS

Eleven per cent of children with cerebral palsy (CP) in Bangladesh had major congenital anomalies. Neurological and musculoskeletal congenital anomalies were the most common. Severe functional motor limitations and associated comorbidities were more common in children presenting with CP and major congenital anomalies.

Application of MIRU-VNTR on smear slides: a shortcut for detection of polyclonal infections in tuberculosis patients

Mixed (polyclonal) infections are one of the main problems in tuberculosis (TB) management. The best available method for detecting polyclonal infections in TB is mycobacterial interspersed repetitive unit-variable number tandem repeat (MIRU-VNTR). According to multiple studies, MIRU-VNTR method can be applied to detect TB-related polyclonal infections in sputum samples or cultures. Setup of MIRU-VNTR on smear slides can be an efficient approach, regardless of the limitations of cultures and sputum samples in many laboratories. The present study aimed at investigating the diagnostic potential of MIRU-VNTR on smear slides in detecting mixed infections. Ziehl-Neelsen-stained microscopic slides were prepared from 14 clinical specimens. For amplifying 24 MIRU-VNTR loci, PCR assay was performed on the smear slides, clinical specimens, and cultures. Based on the 24-locus MIRU-VNTR analysis, polyclonal infections were reported in 42.85% of smear slides, while the corresponding rate was estimated at 57.1% (8/14) in the clinical samples. In the corresponding cultures, the rate of mixed infection was 7.14% (1/14). Use of smear slides can be a safe option for transferring clinical specimens between environmental and reference laboratories. Considering their significant impact on TB treatment, it is essential to diagnose mixed infections in low-resource countries with a high prevalence of mixed infections. The present findings show that direct MIRU-VNTR on smear slides can be conveniently used for the detection of mixed infections.

Detecting TP53 mutations in diagnostic and archival liquid-based Pap samples from ovarian cancer patients using an ultra-sensitive ddPCR method

High-grade serous ovarian cancer (HGSOC) is the most common subtype of epithelial ovarian cancer and early detection is challenging. TP53 mutations are a hallmark of HGSOC and detection of these mutations in liquid-based Pap samples could provide a method for early diagnosis. Here we evaluate the use of IBSAFE, an ultra-sensitive droplet digital PCR (ddPCR) method, for detecting TP53 mutations in liquid-based Pap samples collected from fifteen women at the time of diagnosis (diagnostic samples) and/or up to seven years prior to diagnosis (archival samples). We analysed tumours for somatic TP53 mutations with next generation sequencing and were able to detect the corresponding mutations in diagnostic samples from six of eight women, while one patient harboured a germline mutation. We further detected a mutation in an archival sample obtained 20 months prior to the ovarian cancer diagnosis. The custom designed IBSAFE assays detected minor allele frequencies (MAFs) with very high assay sensitivity (MAF = 0.0068%) and were successful despite low DNA abundance (0.17–206.14 ng, median: 17.27 ng). These results provide support for further evaluation of archival liquid-based Pap samples for diagnostic purposes and demonstrate that ultra-sensitive ddPCR should be evaluated for ovarian cancer screening in high-risk groups or in the recurrent setting.

Genomic test ends a long diagnostic odyssey in a patient with resistance to thyroid hormones

Background

Resistance to thyroid hormones is a very rare condition, which is often misdiagnosed and mistreated. The cases where there is a concomitant autoimmune thyroid disorder are ultra-rare and particularly challenging to treat. Diagnostic and research-based genomic testing can sometimes identify pathogenic variants unrelated to the primary reason for testing (incidental findings).

Case presentation

We present a patient with thyroid resistance associated with hypothyroid Hashimoto thyroiditis. The long diagnostic odyssey spanning over 20-years included repeated misdiagnoses and mistreatments and was concluded by a research-based genomic testing, identifying a “de novo” THRB pathogenic variant. The varying sensitivity of various tissues to thyroid hormones accompanied by hypothyroid Hashimoto thyroiditis continues to pose a significant treatment challenge.

Conclusions

Thyroid hormone resistance continues to be an un(der)- and misdiagnosed thyroid condition whose management is particularly challenging when associated with autoimmune thyroid disease. Whole exome sequencing has the potential to identify THRB pathogenic variants as incidental findings. Reporting such secondary findings from genomic testing may be particularly important in the context of the rarity of the condition and the potential clinical consequences of misdiagnosis and mistreatment.

Whole-exome sequencing reveals a novel mutation of MT-ND5 gene in a mitochondrial cardiomyopathy pedigree: Patients who show biventricular hypertrophy, hyperlactacidemia, pulmonary hypertension, and decreased exercise tolerance

Objective:

The aim of the present study was to determine whether pathogenic mutations were present in families with mitochondrial cardiomyopathy that presented during adolescence.

Methods:

The proband was a 21-year-old man who presented clinically with palpitations, chest tightness, pulmonary hypertension, and limited exercise tolerance. Cardiac magnetic resonance imaging studies showed biventricular cardiac hypertrophy. We determine whether pathogenic mutations were present by whole-exome sequencing (WES) in families.

Results:

Screening of the family using tandem mass spectrometry showed elevated lactic acid levels, glutaric aciduria, a mildly increased glutarylcarnitine-to-octanoylcarnitine ratio, and normal blood α-glucosidase, which was consistent with a respiratory chain complex 1 metabolic disorder. We identified a novel mutation of MT-ND5, c.1315A>G (p.Thr439Ala). Skeletal muscle biopsy histology showed predominantly ragged red fibers and few ragged blue fibers, which was consistent with mitochondrial myopathy.

Conclusion:

In the present study, we identified a novel mutation of MT-ND5, c.1315A>G (p.Thr439Ala), in a family pedigree using WES.

Ethical, social, and cultural issues related to clinical genetic testing and counseling in low- and middle-income countries: a systematic review

PURPOSE

We performed a systematic review of the ethical, social, and cultural issues associated with delivery of genetic services in low- and middle-income countries (LMICs).

METHODS

We searched 11 databases for studies addressing ethical, social, and/or cultural issues associated with clinical genetic testing and/or counselling performed in LMICs. Narrative synthesis was employed to analyze findings, and resultant themes were mapped onto the social ecological model (PROSPERO #CRD42016042894).

RESULTS

After reviewing 13,308 articles, 192 met inclusion criteria. Nine themes emerged: (1) genetic counseling has a tendency of being directive, (2) genetic services have psychosocial consequences that require improved support, (3) medical genetics training is inadequate, (4) genetic services are difficult to access, (5) social determinants affect uptake and understanding of genetic services, (6) social stigma is often associated with genetic disease, (7) family values are at risk of disruption by genetic services, (8) religious principles pose barriers to acceptability and utilization of genetic services, and (9) cultural beliefs and practices influence uptake of information and understanding of genetic disease.

CONCLUSION

We identified a number of complex and interrelated ethical, cultural, and social issues with implications implications for further development of genetic services in LMICs.

Measuring the impact of genetic knowledge on intentions and attitudes of the community towards expanded preconception carrier screening

BACKGROUND

Preconception carrier screening (PCS) provides the potential to empower couples to make reproductive choices before having an affected child. An important question is what factors influence the decision to use or not use PCS.

METHODS

We analysed the relationship between knowledge, attitudes and intentions to participate in PCS using logistic regression in 832 participants in Western Australia.

RESULTS

Two-thirds of participants said they would take the test, with 92% of these supporting screening for diseases reducing the lifespan of children and infants. Those who had good genetic knowledge were seven times more likely to intend to use PCS (p≤0.001), while those with high genetic knowledge were four times more likely to (p=0.002) and raised concerns such as insurance and confidentiality.Decreasing genetic knowledge correlated positively with religiosity and apprehension (p≤0.001), which correlated negatively with intention to use PCS (p≤0.001). Increasing genetic knowledge correlated positively with factors representing positive attitudes (p≤0.001), which correlated positively with intention to use PCS (p≤0.001). Many participants with good genetic knowledge nevertheless answered questions that tested understanding incorrectly.80% of participants stated they would prefer to access the test through their general practitioners and 30% would pay up to $A200.

CONCLUSIONS

Knowledge is instrumental in influencing participation. Having good genetic knowledge may not be enough to understand core concepts of PCS and may impact informed decision-making. This study recommends that continuous education of health professionals and thus the community, in PCS is crucial to reduce misconceptions.

Introducing medical genetics services in Ethiopia using the MiGene Family History App

PURPOSE

Almost all low-income countries and many middle-income countries lack the capacity to deliver medical genetics services. We developed the MiGene Family History App (MFHA), which assists doctors with family history collection and population-level epidemiologic analysis. The MFHA was studied at St. Paul's Hospital in Addis Ababa, Ethiopia.

METHODS

A needs assessment was used to assess Ethiopian physicians' experience with genetics services. The MFHA then collected patient data over a 6-month period.

RESULTS

The majority of doctors provide genetics services, with only 16% reporting their genetics knowledge is sufficient. A total of 1699 patients from the pediatric ward (n = 367), neonatal intensive care unit (NICU) (n = 477), and antenatal clinic (n = 855) were collected using the MFHA with a 4% incidence of a MFHA-screened condition present. The incidence was 11.7% in the pediatric ward, 3% in the NICU, and 0.5% in the antenatal clinic. Heart malformations (5.5% of patients) and trisomy 21 (4.4% of patients) were the most common conditions in the pediatric ward.

CONCLUSION

Medical genetics services are needed in Ethiopia. As other countries increase their genetics capacity, the MFHA can provide fundamental genetics services and collect necessary epidemiologic data.

Genomic medicine for kidney disease

Technologies such as next-generation sequencing and chromosomal microarray have advanced the understanding of the molecular pathogenesis of a variety of renal disorders. Genetic findings are increasingly used to inform the clinical management of many nephropathies, enabling targeted disease surveillance, choice of therapy, and family counselling. Genetic analysis has excellent diagnostic utility in paediatric nephrology, as illustrated by sequencing studies of patients with congenital anomalies of the kidney and urinary tract and steroid-resistant nephrotic syndrome. Although additional investigation is needed, pilot studies suggest that genetic testing can also provide similar diagnostic insight among adult patients. Reaching a genetic diagnosis first involves choosing the appropriate testing modality, as guided by the clinical presentation of the patient and the number of potential genes associated with the suspected nephropathy. Genome-wide sequencing increases diagnostic sensitivity relative to targeted panels, but holds the challenges of identifying causal variants in the vast amount of data generated and interpreting secondary findings. In order to realize the promise of genomic medicine for kidney disease, many technical, logistical, and ethical questions that accompany the implementation of genetic testing in nephrology must be addressed. The creation of evidence-based guidelines for the utilization and implementation of genetic testing in nephrology will help to translate genetic knowledge into improved clinical outcomes for patients with kidney disease.

Whole exome sequencing in neurogenetic odysseys: An effective, cost- and time-saving diagnostic approach

BACKGROUND

Diagnostic trajectories for neurogenetic disorders frequently require the use of considerable time and resources, exposing patients and families to so-called "diagnostic odysseys". Previous studies have provided strong evidence for increased diagnostic and clinical utility of whole-exome sequencing in medical genetics. However, specific reports assessing its utility in a setting such as ours- a neurogeneticist led academic group serving in a low-income country-are rare.

OBJECTIVES

To assess the diagnostic yield of WES in patients suspected of having a neurogenetic condition and explore the cost-effectiveness of its implementation in a research group located in an Argentinean public hospital.

METHODS

This is a prospective study of the clinical utility of WES in a series of 40 consecutive patients selected from a Neurogenetic Clinic of a tertiary Hospital in Argentina. We evaluated patients retrospectively for previous diagnostic trajectories. Diagnostic yield, clinical impact on management and economic diagnostic burden were evaluated.

RESULTS

We demonstrated the clinical utility of Whole Exome Sequencing in our patient cohort, obtaining a diagnostic yield of 40% (95% CI, 24.8%-55.2%) among a diverse group of neurological disorders. The average age at the time of WES was 23 (range 3-70). The mean time elapsed from symptom onset to WES was 11 years (range 3-42). The mean cost of the diagnostic workup prior to WES was USD 1646 (USD 1439 to 1853), which is 60% higher than WES cost in our center.

CONCLUSIONS

WES for neurogenetics proved to be an effective, cost- and time-saving approach for the molecular diagnosis of this heterogeneous and complex group of patients.

Hospital Epidemiology of Methicillin-Resistant Staphylococcus aureus in a Tertiary Care Hospital in Moshi, Tanzania, as Determined by Whole Genome Sequencing

Objective

To determine molecular epidemiology of methicillin-resistant S. aureus in Tanzania using whole genome sequencing.

Methods

DNA from 33 Staphylococcus species was recovered from subcultured archived Staphylococcus isolates. Whole genome sequencing was performed on Illumina Miseq using paired-end 2 × 250 bp protocol. Raw sequence data were analyzed using online tools.

Results

Full susceptibility to vancomycin and chloramphenicol was observed. Thirteen isolates (43.3%) resisted cefoxitin and other antimicrobials tested. Multilocus sequence typing revealed 13 different sequence types among the 30 S. aureus isolates, with ST-8 (n = seven, 23%) being the most common. Gene detection in S. aureus stains were as follows: mecA, 10 (33.3%); pvl, 5 (16.7%); tst, 2 (6.7%). The SNP difference among the six Tanzanian ST-8 MRSA isolates ranged from 24 to 196 SNPs and from 16 to 446 SNPs when using the USA300_FPR3757 or the USA500_2395 as a reference, respectively. The mutation rate was 1.38 × 10⁻¹¹ SNPs/site/year or 1.4 × 10⁻⁶ SNPs/site/year as estimated by USA300_FPR3757 or the USA500_2395, respectively.

Conclusion

S. aureus isolates causing infections in hospitalized patients in Moshi are highly diverse and epidemiologically unrelated. Temporal phylogenetic analysis provided better resolution on transmission and introduction of MRSA and it may be important to include this in future routines.

Ethical issues in managing Lysosomal storage disorders in children in low and middle income countries

The lysosomal storage diseases are a group of rare, inherited metabolic diseases affecting about 1 in 7000 to 8000 people. In recent years, the introduction of enzyme replacement therapy, substrate reduction therapy and small molecule therapy, has changed the natural course of this otherwise progressive group of disorders leading to severe morbidity and early mortality. These treatment options, however, are extremely expensive and are needed for life thus presenting an economical as well as ethical challenge to the affected families and the health care system of a country. This paper presents a case for the prevention of the lysosomal storage disorders as a model for other inherited metabolic disorders in the form of antenatal testing and cascade screeningfor couples and families at risk of having affected off-springs and compares it to the cost incurred on the enzyme replacement therapy in the backdrop of the health care prioritiesof Pakistan, a low middle income country. Similar economic and ethical challenges are faced by most low and middle income countries. The literature search was done using Pubmed and Clinical trials databases using key words: “Lysosomal storage disorders”, “natural course”, “ethics”, “cascade screening”, “Thalassemia” and “cascade screening”. A total of 225 articles in English language were scanned from 1980-2016, 80 articles describing the natural course of LSD with and without ERT, ethical issues related to the treatment of LSD and strategies employed for the prevention of genetic disorders were prioritized.

Genomic diagnostics within a medically underserved population: efficacy and implications

PurposeWe integrated whole-exome sequencing (WES) and chromosomal microarray analysis (CMA) into a clinical workflow to serve an endogamous, uninsured, agrarian community.MethodsSeventy-nine probands (newborn to 49.8 years) who presented between 1998 and 2015 remained undiagnosed after biochemical and molecular investigations. We generated WES data for probands and family members and vetted variants through rephenotyping, segregation analyses, and population studies.ResultsThe most common presentation was neurological disease (64%). Seven (9%) probands were diagnosed by CMA. Family WES data were informative for 37 (51%) of the 72 remaining individuals, yielding a specific genetic diagnosis (n = 32) or revealing a novel molecular etiology (n = 5). For five (7%) additional subjects, negative WES decreased the likelihood of genetic disease. Compared to trio analysis, "family" WES (average seven exomes per proband) reduced filtered candidate variants from 22 ± 6 to 5 ± 3 per proband. Nineteen (51%) alleles were de novo and 17 (46%) inherited; the latter added to a population-based diagnostic panel. We found actionable secondary variants in 21 (4.2%) of 502 subjects, all of whom opted to be informed.ConclusionCMA and family-based WES streamline and economize diagnosis of rare genetic disorders, accelerate novel gene discovery, and create new opportunities for community-based screening and prevention in underserved populations.

Ethical, social, and cultural issues related to clinical genetic testing and counseling in low- and middle-income countries: protocol for a systematic review

BACKGROUND

There has been little focus in the literature on how to build genetic testing and counseling services in low- and middle-income countries in a responsible, ethical, and culturally appropriate manner. It is unclear to what extent this area is being explored and what form further research should take. The proposed knowledge synthesis aims to fill this gap in knowledge and mine the existing data to determine the breadth of work in this area and identify ethical, social, and cultural issues that have emerged.

METHODS/DESIGN

An integrated knowledge translation approach will be undertaken by engaging knowledge users throughout the review to ensure relevance to their practice. Electronic databases encompassing various disciplines, such as healthcare, social sciences, and public health, will be searched. Studies that address clinical genetic testing and/or counseling and ethical, social, and/or cultural issues of these genetic services, and are performed in low- and middle-income countries as defined by World Bank will be considered for inclusion. Two independent reviewers will be involved in a two-stage literature screening process, data extraction, and quality appraisal. Studies included in the review will be analyzed by thematic analysis. A narrative synthesis guided by the social ecological model will be used to summarize findings.

DISCUSSION

This systematic review will provide a foundation of evidence regarding ethical, social, and cultural issues related to clinical genetic testing and counseling in low- and middle-income countries. Using the social ecological model as a conceptual framework will facilitate the understanding of broader influences of the sociocultural context on an individual's experience with clinical genetic testing and counseling, thereby informing interdisciplinary sectors in future recommendations for practice and policy.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42016042894.

Identifying opportunities for collaboration and growth of genetic counseling services in the Asia Region

The Genetic Counseling Pre-Conference Workshop (GCPCW) was held on September 16, 2015, in Hanoi, Vietnam. We report the GCPCW outcomes obtained from pre- and post-conference questionnaires, case-review breakout session, and an open discussion of needs for genetic counseling services in the Asia region. The GCPCW participants completed questionnaires with closed- and open-ended questions regarding the status and needs of providing genetic counseling services in Asia. Utilizing thematic content analysis, common themes shared during the case-review breakout session are summarized and survey results are tabulated. Of the 71 participants, pre- and post-conference questionnaires were returned by 57 (80%) and 44 (62%) individuals, respectively. Of the 42 participants who did not identify themselves as students in training, 36 (86%) stated they are currently providing genetic counseling services. Participants cited that the most useful information obtained during the GCPCW related to the status of genetic counseling services in the region, discovery of shared challenges, professional networking, and the need to establish genetic counseling training programs and its accreditation. The GCPCW provided a collaborative forum to address current challenges and needs of genetic counseling services in the region. Strategies were identified to foster genetic counseling training and clinical service opportunities.

Neonatal Screening: Cost-utility Analysis for Galactosemia

BACKGROUND

Galactosemia is a congenital metabolic disorder that can damage the health of a newborn. Screening is an important step to prevent and treat this condition. Due to increasing health care costs and limited financial resources of health systems, the most suitable economic analysis tool should be applied. The aim of this study was to analyze the cost-utility of neonatal screening program for diagnosing galactosemia in Fars province, Iran.

METHODS

In this cross-sectional study and cost-utility analysis in the cost of screening for galactosemia and its financial effects, decision tree model and society's viewpoint were used. The population of study was 81837 infants referred to Neonatal Screening Laboratory (Nader Kazemi Clinic) affiliated to Shiraz University of Medical Sciences (SUMS), Iran, in 2010. Quality of life in two groups of patients was evaluated by using the time trade-off. The best intervention option was selected by using the Incremental Cost-effectiveness Ratio.

RESULTS

The estimated cost of diagnosed through screening and without screening were 43519911 and 130011168 Iranian Rails (4222.00 $ and 12615.00 $), respectively. Therefore, there was a saving of 201443240.99 Iranian Rails (19641.00 $), for each patient annually.

CONCLUSION

The screening program can improve both the qualitative and quantitative lifestyle of people and increase savings in health care system. Policymakers could use the results to design new policies based on the necessity of screening.

Swedish parents' interest in preconception genetic carrier screening

INTRODUCTION

Genetic technologies advance rapidly. It is possible to undergo genetic carrier screening before pregnancy to examine genetic risks to future offspring. We aimed to investigate parents' interest and motives towards preconception genetic carrier screening (PCS) as well as factors associated with interest in PCS.

MATERIAL AND METHODS

Our study sample consists of 777 parent couples within the longitudinal Swedish Pregnancy Planning study. Women responded to questionnaires at three occasions: in early pregnancy, late pregnancy, and one year after childbirth. Male partners responded to one questionnaire one year after childbirth.

RESULTS

One-third of the parents were positive (30% versus 34% of women and men, respectively), less than a third were negative (26% versus 28%), and 45% versus 38% were uncertain about whether to consider PCS before a future pregnancy. No differences in PCS interest were found between women and men (P = 0.091), but a higher proportion of women were concerned about negative consequences (53% versus 46%, P < 0.003) and were 'opposed to such a way of child selection' (31.8% versus 25.2%, P = 0.002). Factors associated with PCS interest were experiences of prenatal diagnostics and positive attitudes towards finding out or choosing sex of one's child (women), and prenatal diagnostics, self-rated poor health, and pregnancy planning (men).

CONCLUSION

Both women and men had relatively high uncertainty towards PCS, but women were more concerned about negative consequences. The future extent of the clinical utility of PCS is currently unknown, but parents' interests and doubts are important aspects to consider.

Interpretations of education about gene-environment influences on health in rural Ethiopia: the context of a neglected tropical disease

Background

Misunderstandings of the role of genetics in disease development are associated with stigmatizing behaviors and fatalistic attitudes about prevention. This report describes an evaluation of community understanding of an educational module about genetic and environmental influences on the development of podoconiosis, a neglected tropical disease endemic in highland Ethiopia.

Methods

A qualitative process assessment was conducted as part of a large prospective intervention trial in August 2013, in Wolaita Zone, southern Ethiopia. Sixty five participants were purposively selected from 600 households randomized to receive the inherited susceptibility module. The educational module used pictorial representations and oral explanations of the interaction of inherited sensitivity and soil exposure and was delivered by lay health educators in participants' homes. Data were collected using semi-structured individual interviews (IDIs) or focus group discussions (FGDs).

Results

Qualitative analyses showed that most participants improved their understanding of inherited soil sensitivity and susceptibility to podoconiosis. Participants linked their new understanding to decreased stigma-related attitudes. The module also corrected misconceptions that the condition was contagious, again diminishing stigmatizing attitudes. Lastly, these improvements in understanding increased the perceived value of foot protection.

Conclusions

Taken together, these improvements support the acceptability, feasibility and potential benefits of implementing gene-environment education in low and middle income countries.

Public Perceptions of Recessive Carrier Testing in the Preconception and Prenatal Periods

OBJECTIVE

To explore public perceptions of preconception and prenatal recessive carrier testing.

DESIGN

Qualitative, descriptive.

SETTING

Chat rooms located in four websites targeted to those who are pregnant or planning a pregnancy.

PARTICIPANTS

Anonymous comments (N = 1925) in online chat rooms.

METHODS

The Centers for Disease Control and Prevention's (CDC) Analytic validity, Clinical validity, Clinical utility, Ethical, legal, social implications Model Process (ACCE) for evaluating a genetic test guided this deductive-inductive content analysis.

RESULTS

Participant perceptions of the clinical utility of recessive carrier screening with universal carrier panels are multidimensional. Data analysis revealed four a priori deductive themes present in the data. Secondary inductive analysis produced 20 themes, which exceeded the scope of the CDC's ACCE Model Process for assessing the clinical utility of a genetic test.

CONCLUSION

Participant perceptions of carrier testing are important to consider in the clinical utility of carrier testing. Participant perceptions of clinical utility vary from those of the CDC's ACCE Model Process and should be considered in evaluation of the clinical utility of recessive carrier testing in the preconception and prenatal populations.

Epidemiology and genetics of cystic fibrosis in Asia: In preparation for the next-generation treatments

Cystic fibrosis (CF) in the Asian population is less frequently reported due to under-diagnosis and lack of centralized CF patient registries. Clinical studies on CF cases from Asia have documented a severe course of the disease. The spectrum of the cystic fibrosis transmembrane conductance regulator (CFTR) variants in this population is quite heterogeneous. In total, 166 variants have been reported on approximately 3700 Asian CF chromosomes. The frequency of F508del among Asians is low compared with Caucasians. Recent in vitro studies have shown promise of small molecule correction and potentiation of 45 different CFTR variants. Of these variants, 16 (including G551D and F508del) have also been observed among Asian CF individuals. We suggest undertaking molecular studies extensively to annotate CFTR variants that will help Asian CF individuals to benefit from the precision medicine gaining momentum in the Western countries.

Epidemiology and diagnosis of lysosomal storage disorders; challenges of screening

The lysosomal storage disorders (LSDs) are a group of genetic disorders resulting from defective lysosomal metabolism and subsequent accumulation of substrates. Patients present with a large phenotypic spectrum of disease manifestations that are generally not specific for LSDs, leading to considerable diagnostic delay and missed cases. Introduction of new disease modifying therapies for LSDs has made early diagnosis a priority. Increased awareness, but particularly the introduction of screening programs allow for early diagnosis and timely initiation of treatment. This review will provide insight into the epidemiology and diagnostic process for LSDs. In addition, challenges for carrier screening, high-risk screening and newborn population screening for LSDs are discussed.

Hyperhomocysteinemia: related genetic diseases and congenital defects, abnormal DNA methylation and newborn screening issues

Homocysteine, a sulfur-containing amino acid derived from the methionine metabolism, is located at the branch point of two pathways of the methionine cycle, i.e. remethylation and transsulfuration. Gene abnormalities in the enzymes catalyzing reactions in both pathways lead to hyperhomocysteinemia. Hyperhomocysteinemia is associated with increased risk for congenital disorders, including neural tube closure defects, heart defects, cleft lip/palate, Down syndrome, and multi-system abnormalities in adults. Since hyperhomocysteinemia is known to affect the extent of DNA methylation, it is likely that abnormal DNA methylation during embryogenesis, may be a pathogenic factor for these congenital disorders. In this review we highlight the importance of homocysteinemia by describing the genes encoding for enzymes of homocysteine metabolism relevant to the clinical practice, especially cystathionine-β-synthase and methylenetetrahydrofolate reductase mutations, and the impairment of related metabolites levels. Moreover, a possible correlation between hyperhomocysteine and congenital disorders through the involvement of abnormal DNA methylation during embryogenesis is discussed. Finally, the relevance of present and future diagnostic tools such as tandem mass spectrometry and next generation sequencing in newborn screening is highlighted.