ABSTRACT
The nuclear pore complex (NPC) is a multi-protein complex that regulates the trafficking of macromolecules between the nucleus and cytoplasm. Genetic variants in components of the NPC have been shown to cause a range of neurological disorders, including intellectual disability and microcephaly. Translocated promoter region, nuclear basket protein (TPR) is a critical scaffolding element of the nuclear facing interior of the NPC. Here, we present two siblings with biallelic variants in TPR who present with a phenotype of microcephaly, ataxia and severe intellectual disability. The variants result in a premature truncation variant, and a splice variant leading to a 12-amino acid deletion respectively. Functional analyses in patient fibroblasts demonstrate significantly reduced TPR levels, and decreased TPR-containing NPC density. A compensatory increase in total NPC levels was observed, and decreased global RNA intensity in the nucleus. The discovery of variants that partly disable TPR function provide valuable insight into this essential protein in human disease, and our findings suggest that TPR variants are the cause of the siblings' neurological disorder.
Subject(s)
Intellectual Disability , Microcephaly , Humans , Intellectual Disability/genetics , Microcephaly/genetics , Nuclear Pore Complex Proteins/genetics , Nuclear Pore Complex Proteins/metabolism , Nuclear Proteins/genetics , Promoter Regions, Genetic/genetics , Proto-Oncogene Proteins/geneticsABSTRACT
PURPOSE: Genetic variants causing aberrant premessenger RNA splicing are increasingly being recognized as causal variants in genetic disorders. In this study, we devise standardized practices for polymerase chain reaction (PCR)-based RNA diagnostics using clinically accessible specimens (blood, fibroblasts, urothelia, biopsy). METHODS: A total of 74 families with diverse monogenic conditions (31% prenatal-congenital onset, 47% early childhood, and 22% teenage-adult onset) were triaged into PCR-based RNA testing, with comparative RNA sequencing for 19 cases. RESULTS: Informative RNA assay data were obtained for 96% of cases, enabling variant reclassification for 75% variants that can be used for genetic counseling (71%), to inform clinical care (32%) and prenatal counseling (41%). Variant-associated mis-splicing was highly reproducible for 28 cases with samples from ≥2 affected individuals or heterozygotes and 10 cases with ≥2 biospecimens. PCR amplicons encompassing another segregated heterozygous variant was vital for clinical interpretation of 22 of 79 variants to phase RNA splicing events and discern complete from partial mis-splicing. CONCLUSION: RNA diagnostics enabled provision of a genetic diagnosis for 64% of recruited cases. PCR-based RNA diagnostics has capacity to analyze 81.3% of clinically significant genes, with long amplicons providing an advantage over RNA sequencing to phase RNA splicing events. The Australasian Consortium for RNA Diagnostics (SpliceACORD) provide clinically-endorsed, standardized protocols and recommendations for interpreting RNA assay data.
Subject(s)
RNA Splicing , RNA , Adolescent , Adult , Child, Preschool , Humans , Mutation , RNA/genetics , RNA Splicing/genetics , Sequence Analysis, RNA , Exome SequencingABSTRACT
OBJECTIVE: To establish the epidemiological, clinical, pathological and genetic characteristics of epidermolysis bullosa (EB) in New Zealand (NZ). METHODS: Participants were recruited through the Dystrophic Epidermolysis Bullosa Research Association of New Zealand (DEBRA NZ). Dedicated EB nurse medical records, Genetic Health Service NZ (GHSNZ) records and, where available, public hospital records were manually reviewed for relevant clinical data. RESULTS: Ninety-two participants took part in the study (56% participation rate). Forty-nine (53%) participants had EB simplex (EBS), 40 (43%) had dystrophic EB (DEB), and 3 (3%) had junctional EB (JEB). Point prevalence for EB of all types was 19.5 per million, and 10.4, 8.6 and 0.9 per million for EBS, DEB and JEB, respectively. Thirty-four participants had intermediate or severe EB. There were 29 paediatric cases and almost even numbers of males and females. Compared to NZ European and Maori, prevalence rates were lower for Pacific and Asian people and higher in the Middle Eastern/Latin American/African population. Eight out of 14 skin biopsy results were informative, and 14 of 15 genetic test results were informative. CONCLUSION: New Zealand has similar prevalence rates of EB compared with other national cohorts. This is likely to be an underestimate due to methodological limitations. Recent advancements in genomic testing have resulted in an improved diagnostic rate in our population. Further research into ethnic differences in prevalence, and exploring the characteristics of lethal forms of EB, is warranted. A dynamic registry may be helpful for the EB community in NZ.
Subject(s)
Epidermolysis Bullosa/epidemiology , Adolescent , Adult , Age Distribution , Aged , Aged, 80 and over , Biopsy/statistics & numerical data , Child , Child, Preschool , Female , Genetic Testing/statistics & numerical data , Humans , Infant , Infant, Newborn , Male , Middle Aged , New Zealand/epidemiology , Prevalence , Racial Groups/statistics & numerical data , Sex Distribution , Young AdultABSTRACT
PURPOSE: Widespread, quality genomics education for health professionals is required to create a competent genomic workforce. A lack of standards for reporting genomics education and evaluation limits the evidence base for replication and comparison. We therefore undertook a consensus process to develop a recommended minimum set of information to support consistent reporting of design, development, delivery, and evaluation of genomics education interventions. METHODS: Draft standards were derived from literature (25 items from 21 publications). Thirty-six international experts were purposively recruited for three rounds of a modified Delphi process to reach consensus on relevance, clarity, comprehensiveness, utility, and design. RESULTS: The final standards include 18 items relating to development and delivery of genomics education interventions, 12 relating to evaluation, and 1 on stakeholder engagement. CONCLUSION: These Reporting Item Standards for Education and its Evaluation in Genomics (RISE2 Genomics) are intended to be widely applicable across settings and health professions. Their use by those involved in reporting genomics education interventions and evaluation, as well as adoption by journals and policy makers as the expected standard, will support greater transparency, consistency, and comprehensiveness of reporting. Consequently, the genomics education evidence base will be more robust, enabling high-quality education and evaluation across diverse settings.