Shwachman Diamond syndrome: narrow genotypic spectrum and variable clinical features

BACKGROUND AND OBJECTIVES

Shwachman Diamond syndrome (SDS) is an inherited bone marrow failure syndrome (IBMFS) associated with pancreatic insufficiency, neutropenia, and skeletal dysplasia. Biallelic pathogenic variants (PV) in SBDS account for >90% of SDS. We hypothesized that the SDS phenotype varies based on genotype and conducted a genotype-phenotype correlation study to better understand these complexities.

METHODS

We reviewed records of all patients with SDS or SDS-like syndromes in the National Cancer Institute's (NCI) IBMFS study. Additional published SDS cohorts were reviewed and compared with the NCI cohort.

RESULTS

PVs in SBDS were present in 32/47 (68.1%) participants. Biallelic inheritance of SBDS c.258 + 2T > C and c.183_184TA > CT was the most common genotype in our study (25/32, 78.1%) and published cohorts. Most patients had the SDS hallmark features of neutropenia (45/45, 100%), pancreatic insufficiency (41/43, 95.3%), and/or bony abnormalities (29/36, 80.6%). Developmental delay was common (20/34, 58.8%). Increased risk of hematologic malignancies at young ages and the rarity of solid malignancies was observed in both the NCI cohort and published studies.

CONCLUSIONS

SDS is a complex childhood illness with a narrow genotypic spectrum. Patients may first present to primary care, gastroenterology, orthopedic, and/or hematology clinics. Coordinated multidisciplinary care is important for diagnosis and patient management.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT00027274.

IMPACT

The clinical and genetic spectrum of Shwachman Diamond Syndrome was comprehensively evaluated, and the findings illustrate the importance of a multidisciplinary approach for these complex patients. Our work reveals: 1. a narrow genotypic spectrum in SDS; 2. a low risk of solid tumors in patients with SDS; 3. patients with SDS have clinical manifestations in multiple organ systems.

Next-generation sequencing errors due to genetic variation in WRAP53 encoding TCAB1 on chromosome 17

Next-generation sequencing (NGS) is a valuable tool, but has limitations in sequencing through repetitive runs of single nucleotides (homopolymers). Pathogenic germline variants in WRAP53 encoding telomere Cajal body protein 1 (TCAB1) are a known cause of dyskeratosis congenita. We identified a significant NGS error in WRAP53, c.1562dup, p.Ala522Glyfs*8 (rs755116516 G>-/GG/GGG) that did not validate by Sanger sequencing. This error occurs because rs755116516 G>-/GG/GGG (Chr17:7,606,714) is polymorphic, and variants at this site challenge the ability of NGS to accurately call the correct number of nucleotides in a homopolymer run. This was further complicated by the fact that chr17:7,606,721 (rs769202794) is multiallelic G>A, C, T, and that chr17:7,606,722 is also multiallelic (rs7640C>A/G/T and rs373064567C>delC). In addition to the expert interpretation of potentially clinically actionable variants, it recommended that all variants in regions of the genome with homopolymers be validated by Sanger sequencing before clinical action.

Genetic testing in severe aplastic anemia is required for optimal hematopoietic cell transplant outcomes

Patients with severe aplastic anemia (SAA) can have an unrecognized inherited bone marrow failure syndrome (IBMFS) because of phenotypic heterogeneity. We curated germline genetic variants in 104 IBMFS-associated genes from exome sequencing performed on 732 patients who underwent hematopoietic cell transplant (HCT) between 1989 and 2015 for acquired SAA. Patients with pathogenic or likely pathogenic (P/LP) variants fitting known disease zygosity patterns were deemed unrecognized IBMFS. Carriers were defined as patients with a single P/LP variant in an autosomal recessive gene or females with an X-linked recessive P/LP variant. Cox proportional hazard models were used for survival analysis with follow-up until 2017. We identified 113 P/LP single-nucleotide variants or small insertions/deletions and 10 copy number variants across 42 genes in 121 patients. Ninety-one patients had 105 in silico predicted deleterious variants of uncertain significance (dVUS). Forty-eight patients (6.6%) had an unrecognized IBMFS (33% adults), and 73 (10%) were carriers. No survival difference between dVUS and acquired SAA was noted. Compared with acquired SAA (no P/LP variants), patients with unrecognized IBMFS, but not carriers, had worse survival after HCT (IBMFS hazard ratio [HR], 2.13; 95% confidence interval[CI], 1.40-3.24; P = .0004; carriers HR, 0.96; 95% CI, 0.62-1.50; P = .86). Results were similar in analyses restricted to patients receiving reduced-intensity conditioning (n = 448; HR IBMFS = 2.39; P = .01). The excess mortality risk in unrecognized IBMFS attributed to death from organ failure (HR = 4.88; P < .0001). Genetic testing should be part of the diagnostic evaluation for all patients with SAA to tailor therapeutic regimens. Carriers of a pathogenic variant in an IBMFS gene can follow HCT regimens for acquired SAA.

Genetic regulation of OAS1 nonsense-mediated decay underlies association with COVID-19 hospitalization in patients of European and African ancestries

The chr12q24.13 locus encoding OAS1-OAS3 antiviral proteins has been associated with coronavirus disease 2019 (COVID-19) susceptibility. Here, we report genetic, functional and clinical insights into this locus in relation to COVID-19 severity. In our analysis of patients of European (n = 2,249) and African (n = 835) ancestries with hospitalized versus nonhospitalized COVID-19, the risk of hospitalized disease was associated with a common OAS1 haplotype, which was also associated with reduced severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) clearance in a clinical trial with pegIFN-λ1. Bioinformatic analyses and in vitro studies reveal the functional contribution of two associated OAS1 exonic variants comprising the risk haplotype. Derived human-specific alleles rs10774671-A and rs1131454 -A decrease OAS1 protein abundance through allele-specific regulation of splicing and nonsense-mediated decay (NMD). We conclude that decreased OAS1 expression due to a common haplotype contributes to COVID-19 severity. Our results provide insight into molecular mechanisms through which early treatment with interferons could accelerate SARS-CoV-2 clearance and mitigate against severe COVID-19.

Abstract 4108: Understanding the role of telomere biology gene variation in cancer etiology

Telomere biology disorders (TBDs) are cancer-prone syndromes associated with increased risk of acute myeloid leukemia (AML), head and neck squamous cell carcinoma (HNSCC), bone marrow failure, pulmonary fibrosis, and liver disease. Germline variants in at least 15 different telomere biology genes have been implicated (ACD, CTC1, TERT, TERC, STN1, NAF1, NOP10, NHP2, TINF2, RTEL1, PARN, ZCCHC8, DKC1, WRAP53, POT1) with autosomal dominant (AD), autosomal recessive (AR), or X-linked (XLR) inheritance as well as de novo occurrence. We hypothesize that TBDs may be more common than the currently estimated 1:1,000,000.

We analyzed the prevalence of germline variants in the 15 TBD-associated genes using 1) The Genome Aggregation Database [gnomAD v2.1.1 non-cancer] and 2) The Cancer Genome Atlas (TCGA). Germline TCGA variants were called using HaplotypeCaller, Freebayes, and UnifiedGenotyper. All variants with minor allele frequency (MAF) &lt;1% in gnomAD non-cancer were considered. They were classified as potentially deleterious based on ClinVar and/or loss of function classification and/or stringent in silico predictions utilizing REVEL, MetaSVM, CADD, BayesDel, Eigen for missense and a combination of spliceAI, spidex, and dbscSNV for splice site variants. For TERC (RNA telomerase template) variants in the pseudoknot/template region were considered deleterious. The known disease-causing inheritance pattern (AD, AR, XLR) for each gene was used to identify TCGA cases with a probable TBD.

There were 1215 potentially deleterious variants in TBD associated genes in the gnomAD v2.1.1 non-cancer dataset (n=134,187 samples) for a combined prevalence of 0.9%, without accounting for zygosity. In genes with AD/AR inheritance, variants were most common in: RTEL1 (249), TERT (104), and PARN (104). CTC1 and WRAP53, both associated with solely AR TBDs, also showed high variant frequencies (280 and 102, respectively). In the TCGA dataset, 9089 cancer cases (32 solid tumors and AML) were evaluated. We identified 227 cases (2.5%) with 161 mono- or biallelic rare, potentially deleterious variants in the 15 genes. Ninety-two cases had a probable underlying TBD [1% of total, 41 male, 51 female, median age at cancer diagnosis 46.5 (1-92) years]. Cancer diagnoses in these 92 cases included 24 solid tumors. The frequency of individuals with deleterious TBD-associated variants ranged from 0.4-2.8% in each of the 24 affected cancers. Notably, the heterozygous frequencies in lung squamous cell carcinoma and liver hepatocellular carcinoma were 1.6% and 2.2%, respectively. Our results show that the prevalence of TBDs may be noticeably higher than previously estimated, specifically in individuals with cancer. TBD-associated pathogenic germline variants may be implicated in the etiology of more solid tumor entities than previously recognized, warranting further studies.

Citation Format: Marena R. Niewisch, Jung Kim, Judith C. Lunger, Lisa J. McReynolds, Sharon A. Savage. Understanding the role of telomere biology gene variation in cancer etiology [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 4108.

Abstract 1428: DNA methylation predicts early onset of primary tumor in patients with Li-Fraumeni syndrome

Background: Li-Fraumeni syndrome (LFS) is an autosomal dominant cancer predisposition syndrome. Approximately 80% of individuals with LFS harbor a germline TP53 pathogenic variant rendering them susceptible to a wide spectrum of early-onset malignancies. A comprehensive surveillance regimen termed the ‘Toronto Protocol’, has recently been adopted for early tumor detection, demonstrating significant improvement in survival among TP53 pathogenic variant carriers. However, the protocol’s “one-size-fits-all” approach fails to consider an individual patient's risk of cancer. We built a machine learning model that predicts early-onset of primary tumors in LFS by estimating the probability of cancer onset before the age of six years, leveraging patient peripheral blood leukocyte methylation profiles.

Methods: We built a gradient-boosted tree model to predict the probability of cancer onset before the age of six using methylation data from 288 TP53 pathogenic variant carriers. An external test set of 82 TP53 pathogenic variant carriers was used to validate our model. To increase the signal-to-noise ratio, methylation probes associated with TP53 status were retained and probes associated with aging were removed. In our study, we were primarily interested in minimizing the false negative rate (i.e. to reduce the number of patients who developed cancer before the age of six but were undetected by our algorithm.

Findings: We correctly predicted whether the first tumor will occur before the age of six with an accuracy of 79% in our external test set. Importantly, our model classified 90% of the patients that developed cancer prior to the age of six correctly. In addition, 81% of the individuals without cancer in the external test set were predicted correctly.

Interpretation: Our tool provides additional value to clinicians in stratifying patients into low- or high-risk groups of developing early-onset malignancies, and helps inform rational use of clinical surveillance tools for early cancer detection, with the ultimate aim to improve overall patient outcomes.

Citation Format: Vallijah Subasri, Benjamin Brew, Lauren Erdman, Tanya Guha, Jordan R. Hansford, Elizabeth Cairney, Carol Portwine, Christine Elser, Jonathan L. Finlay, Kim E. Nichols, Wendy Kohlmann, Noa Alon, Ana Novokmet, Ledia Brunga, Anita Villani, Kelvin C. de Andrade, Payal P. Khincha, Sharon A. Savage, Joshua D. Schiffman, David Malkin, Anna Goldenberg. DNA methylation predicts early onset of primary tumor in patients with Li-Fraumeni syndrome [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1428.

Fundamental immune-oncogenicity trade-offs define driver mutation fitness

Missense driver mutations in cancer are concentrated in a few hotspots1. Various mechanisms have been proposed to explain this skew, including biased mutational processes2, phenotypic differences3-6 and immunoediting of neoantigens7,8; however, to our knowledge, no existing model weighs the relative contribution of these features to tumour evolution. We propose a unified theoretical 'free fitness' framework that parsimoniously integrates multimodal genomic, epigenetic, transcriptomic and proteomic data into a biophysical model of the rate-limiting processes underlying the fitness advantage conferred on cancer cells by driver gene mutations. Focusing on TP53, the most mutated gene in cancer1, we present an inference of mutant p53 concentration and demonstrate that TP53 hotspot mutations optimally solve an evolutionary trade-off between oncogenic potential and neoantigen immunogenicity. Our model anticipates patient survival in The Cancer Genome Atlas and patients with lung cancer treated with immunotherapy as well as the age of tumour onset in germline carriers of TP53 variants. The predicted differential immunogenicity between hotspot mutations was validated experimentally in patients with cancer and in a unique large dataset of healthy individuals. Our data indicate that immune selective pressure on TP53 mutations has a smaller role in non-cancerous lesions than in tumours, suggesting that targeted immunotherapy may offer an early prophylactic opportunity for the former. Determining the relative contribution of immunogenicity and oncogenic function to the selective advantage of hotspot mutations thus has important implications for both precision immunotherapies and our understanding of tumour evolution.

Telomere length and epigenetic clocks as markers of cellular aging: a comparative study

Telomere length (TL) and DNA methylation-based epigenetic clocks are markers of biological age, but the relationship between the two is not fully understood. Here, we used multivariable regression models to evaluate the relationships between leukocyte TL (LTL; measured by qPCR [n = 635] or flow FISH [n = 144]) and five epigenetic clocks (Hannum, DNAmAge pan-tissue, PhenoAge, SkinBlood, or GrimAge clocks), or their epigenetic age acceleration measures in healthy adults (age 19-61 years). LTL showed statistically significant negative correlations with all clocks (qPCR: r =  - 0.26 to - 0.32; flow FISH: r =  - 0.34 to - 0.49; p < 0.001 for all). Yet, models adjusted for age, sex, and race revealed significant associations between three of five clocks (PhenoAge, GrimAge, and Hannum clocks) and LTL by flow FISH (p < 0.01 for all) or qPCR (p < 0.001 for all). Significant associations between age acceleration measures for the same three clocks and qPCR or flow FISH TL were also found (p < 0.01 for all). Additionally, LTL (by qPCR or flow FISH) showed significant associations with extrinsic epigenetic age acceleration (EEAA: p < 0.0001 for both), but not intrinsic epigenetic age acceleration (IEAA; p > 0.05 for both). In conclusion, the relationships between LTL and epigenetic clocks were limited to clocks reflecting phenotypic age. The observed association between LTL and EEAA reflects the ability of both measures to detect immunosenescence. The observed modest correlations between LTL and epigenetic clocks highlight a possible benefit from incorporating both measures in understanding disease etiology and prognosis.

Disease progression and clinical outcomes in telomere biology disorders

Dyskeratosis congenita related telomere biology disorders (DC/TBDs) are characterized by very short telomeres caused by germline pathogenic variants in telomere biology genes. Clinical presentations can affect all organs, and inheritance patterns include autosomal dominant (AD), autosomal recessive (AR), X-linked (XLR), or de novo. This study examined the associations between mode of inheritance with phenotypes and long-term clinical outcomes. Two hundred thirty-one individuals with DC/TBDs (144 male, 86.6% known genotype, median age at diagnosis 19.4 years [range 0 to 71.6]), enrolled in the National Cancer Institute's Inherited Bone Marrow Failure Syndrome Study, underwent detailed clinical assessments and longitudinal follow-up (median follow-up 5.2 years [range 0 to 36.7]). Patients were grouped by inheritance pattern, considering AD-nonTINF2, AR/XLR, and TINF2 variants separately. Severe bone marrow failure (BMF), severe liver disease, and gastrointestinal telangiectasias were more prevalent in AR/XLR or TINF2 disease, whereas pulmonary fibrosis developed predominantly in adults with AD disease. After adjusting for age at DC/TBD diagnosis, we observed the highest cancer risk in AR/XLR individuals. At last follow-up, 42% of patients were deceased with a median overall survival (OS) of 52.8 years (95% confidence interval [CI] 45.5-57.6), and the hematopoietic cell or solid organ transplant-free median survival was 45.3 years (95% CI 37.4-52.1). Significantly better OS was present in AD vs AR/XLR/TINF2 disease (P < .01), while patients with AR/XLR and TINF2 disease had similar survival probabilities. This long-term study of the clinical manifestations of DC/TBDs creates a foundation for incorporating the mode of inheritance into evidence-based clinical care guidelines and risk stratification in patients with DC/TBDs. This trial was registered at www.clinicaltrials.gov as #NCT00027274.

Clinical outcomes in Transient Epileptic Amnesia: a 10-year follow-up cohort study of 47 cases

Objective

Transient epileptic amnesia (TEA) is a form of adult‐onset epilepsy where presenting features are well described, but little is known regarding prognosis. This study aimed to elucidate the long‐term prognosis of TEA regarding seizure control, memory, medical comorbidities, and life expectancy.

Methods

Up‐to‐date clinical information was collected for 47 people diagnosed with TEA who had joined the The Impairment of Memory in Epilepsy (TIME) study 10 years earlier. At entry to the study, information about comorbid conditions was systematically collected. Details regarding subsequent diagnoses, seizure activity, changes to treatment, or reports of cognitive impairment were obtained through the family doctor. The variables of interest were compared with UK population data.

Results

Mortality in the cohort was 21 of 47 (45%), with an average age at death of 82.5 years. Seizures remained well controlled for the majority but medications required adjustments in dose and type for some (28%). A small number (three cases) remained seizure‐free without medication. History of cardiovascular disorders was frequent (78.7%), typically involving hypertension (55.3%). Autoimmune disorders (25.5%), cancer (23.4%), and depression (21.3%) were also commonly reported. Although persisting memory problems were often noted, dementia was diagnosed in seven cases (14.9%). Life expectancy and comorbidities in TEA did not differ from available population norms.

Significance

Results suggest that life expectancy is not reduced in TEA. Although TEA does not appear to be a self‐limiting form of epilepsy, seizures are typically well controlled via medication. Because adjustments to medication may be required, even after long periods of stability, ongoing medical monitoring is recommended. Comorbid vascular disorders are frequent but appear similar to general population estimates. Monitoring mood may be important, given that people with chronic conditions are often vulnerable to depression. Because of persisting memory difficulties, the development of effective memory interventions for people with TEA is warranted.

Lipoprotein particle alterations due to androgen therapy in individuals with dyskeratosis congenita

Background

Dyskeratosis congenita (DC) is a telomere biology disorder associated with high rates of bone marrow failure (BMF) and other medical complications. Oral androgens are successfully used to treat BMF in DC but often have significant side effects, including elevation of serum lipids. This study sought to determine the extent to which oral androgen therapy altered lipid and lipoprotein levels.

Methods

Nuclear magnetic resonance (NMR) was used to evaluate serum lipid profiles, and lipoprotein particle number and size in nine androgen-treated individuals with DC, 45 untreated individuals with DC, 72 unaffected relatives of DC patients, and 19 untreated individuals with a different inherited BMF syndrome, Fanconi anaemia (FA).

Findings

Androgen-treated individuals with DC had significantly decreased serum HDL cholesterol, HDL particle number and HDL particle size (p < 0·001, p < 0·001 and p < 0·001, respectively); significantly increased serum LDL cholesterol and LDL particle number (p < 0·001, p < 0·001, respectively), decreased apoA-I and increased apoB (p < 0⋅001, p < 0⋅05 respectively) when compared with untreated individuals with DC. There were no significant lipid profile differences between untreated DC and untreated FA participants; or between untreated DC participants and their unaffected relatives. Branched chain amino acids and lipoprotein insulin resistance were not significantly different with androgen treatment. GlycA, an inflammatory acute phase reactant, was significantly increased with androgen treatment (p < 0⋅001).

Interpretation

Androgen treatment in DC creates an atherogenic lipoprotein profile, raising concern for the potential of elevated cardiovascular disease risk. Clinical guidelines for individuals on androgens for DC-related BMF should include cardiovascular disease monitoring. These findings could be relevant in individuals treated with androgen for other indications.

Funding

Intramural research programs of the Division of Cancer Epidemiology and Genetics of the National Cancer Institute and National Heart, Lung, and Blood Institute.

Quantification of Discordant Variant Interpretations in a Large Family-Based Study of Li-Fraumeni Syndrome

PURPOSE

The use of the American College of Medical Genetics and Genomics and the Association for Molecular Pathology guidelines has improved germline variant classification concordance, but discrepancies persist, sometimes directly affecting medical management. We evaluated variant discordance between and within families with germline TP53 variants in the National Cancer Institute's Li-Fraumeni syndrome longitudinal cohort study.

MATERIALS AND METHODS

Germline TP53 genetic testing results were obtained from 421 individuals in 140 families. A discordant test result was defined as a report of pathogenicity that differed between two clinical testing laboratories, between a testing laboratory and the ClinVar database, or between either the laboratory or ClinVar database and variant classification by internal study review.

RESULTS

There were 141 variants in 140 families (one family had two different TP53 variants). Fifty-four families had discordant interpretations (54 of 140, 39%). Sixteen families had discordant classifications leading to clinically important differences in medical management (16 of 140, 11%). Interfamilial discordance was observed between four families (two different variants). Intrafamilial discordance was observed within six families. One family experienced both intrafamilial and interfamilial discordance.

CONCLUSION

This large single-gene study found discordant germline TP53 variant interpretations in 39% of families studied; 11% had a variant with the potential to significantly affect medical management. This finding is especially concerning in patients with Li-Fraumeni syndrome because of their exceedingly high risks of multiple cancers and intensive cancer screening and risk-reducing recommendations. Centralized data sharing, gene-specific variant curation guidelines, and provider education for consistent variant interpretation are essential for optimal patient care.

Cancer incidence, patterns, and genotype-phenotype associations in individuals with pathogenic or likely pathogenic germline TP53 variants: an observational cohort study

BACKGROUND

Li-Fraumeni syndrome, caused primarily by pathogenic or likely pathogenic germline TP53 variants, is a rare, variably penetrant, cancer predisposition syndrome with very high risks of cancer starting in childhood, including the risk of multiple primary malignancies over an individual's lifespan. We aimed to characterise and quantify cancer incidence, patterns, and genotype-phenotype associations in individuals with pathogenic or likely pathogenic germline TP53 variants.

METHODS

This observational cohort study was done in 480 carriers of pathogenic or likely pathogenic germline TP53 variants enrolled in the National Cancer Institute's referral-based longitudinal Li-Fraumeni syndrome study between Aug 1, 2011, and March 24, 2020. Data on personal and family history of cancer were obtained through study questionnaires and validated by medical records. Variants were categorised on the basis of both loss-of-function (LOF) and dominant-negative effect (DNE) properties. Cancer incidence associated with Li-Fraumeni syndrome was compared with that of the general population using the Surveillance, Epidemiology, and End Results (SEER) 1975-2017 registry. Cancer incidence was evaluated with family-clustered Cox regression models and competing risk methods. This study is registered with ClinicalTrials.gov, NCT01443468.

FINDINGS

Individuals with Li-Fraumeni syndrome had a nearly 24 times higher incidence of any cancer than the general population (standardised incidence ratio 23·9; 95% CI 21·9-26·0), with the highest comparative incidence from childhood to 30 years of age. The overall cancer incidence remained 10·3 (95% CI 7·9-13·2) times higher than that of the general population after age 50 years. In women, when considering breast cancer as a competing risk, the probability of a first diagnosis of a non-breast cancer malignancy was substantially lower than that of any first cancer (24·4% [95% CI 19·6-30·5] vs 50·4% [43·5-56·5] by age 33·7 years). Overall, DNE_LOF and notDNE_LOF variants were associated with earlier age at first and second cancer compared with notDNE_notLOF and DNE_notLOF variants. The time interval from first to second cancer was shorter among carriers whose first cancer diagnoses were later in life. Multiple cancers were diagnosed within a short timeframe in some individuals, regardless of the order of cancer occurrence.

INTERPRETATION

This study adds granularity to the understanding of cancer incidence and patterns in individuals with pathogenic or likely pathogenic germline TP53 variants. Integration of age range-specific cancer incidence estimates, cancer-free survival by functional variant group, the potential impact of risk-reducing mastectomy on female cancer incidence, and data on subsequent malignancies will be important for the development of strategies to optimise cancer screening and management for these individuals.

FUNDING

Intramural Research Program, Division of Cancer Epidemiology and Genetics, National Institutes of Health.

No negative impact of word retraining on vocabulary use or clarity of communication in semantic dementia

Word retraining techniques can improve picture naming of treated items in people with semantic dementia (SD). The utility of this, however, has been questioned given the propensity for under- and overgeneralization errors in naming in SD. Few studies have investigated the occurrence of such errors. This study examined whether, following tailored word retraining: (1) misuse of words increases, (2) the type of naming errors changes, and/or (3) clarity of communication is reduced. Performance on trained and untrained word naming from nine participants with SD who completed a word retraining programme were analysed. Responses from baseline and post-intervention assessments were coded for misuse (i.e., trained word produced for another target item), error type, and communication clarity. All participants showed significant improvement for trained vocabulary. There was no significant increase in misuse of words, with such errors occurring rarely. At a group level, there was an increased tendency toward omission errors for untrained items, and a reduction in semantically related responses. However, this did not impact on clarity scores with no consistent change across participants. In sum, we found no negative impacts following tailored word retraining, providing further evidence of the benefit of these programmes for individuals with SD.

Analysis of the Li-Fraumeni Spectrum Based on an International Germline TP53 Variant Data Set: An International Agency for Research on Cancer TP53 Database Analysis

Questions

What is the phenotypic spectrum associated with variants in TP53, the gene variant in persons with Li-Fraumeni syndrome, and what mechanisms underlie phenotypic differences?

Findings

In this cohort study, the phenotypes within the classification Li-Fraumeni spectrum were defined, and data from 3034 persons from 1282 families with data available in the International Agency for Research on Cancer TP53 Database were analyzed and classified to reveal meaningful differences in the TP53 variant distribution between patients who met vs those who did not meet Li-Fraumeni syndrome testing criteria.

Meaning

The study results suggest that this classification is a potential step toward understanding the factors that lead to phenotypic differences in the Li-Fraumeni spectrum and may serve as a model for the reclassification of other hereditary conditions with an increased cancer risk.

Importance

Li-Fraumeni syndrome is a cancer predisposition syndrome that is associated with a high, lifelong risk of a broad spectrum of cancers that is caused by pathogenic TP53 germline variants. A definition that reflects the broad phenotypic spectrum that has evolved since the gene discovery is lacking, and mechanisms leading to phenotypic differences remain largely unknown.

Objective

To define the phenotypic spectrum of Li-Fraumeni syndrome and conduct phenotype-genotype associations across the phenotypic spectrum.

Design, Setting, and Participants

We analyzed and classified the germline variant data set of the International Agency for Research on Cancer TP53 database that contains data on a cohort of 3034 persons from 1282 families reported in the scientific literature since 1990. We defined the term Li-Fraumeni spectrum to encompass (1) phenotypic Li-Fraumeni syndrome, defined by the absence of a pathogenic/likely pathogenic TP53 variant in persons/families meeting clinical Li-Fraumeni syndrome criteria; (2) Li-Fraumeni syndrome, defined by the presence of a pathogenic/likely pathogenic TP53 variant in persons/families meeting Li-Fraumeni syndrome testing criteria; (3) attenuated Li-Fraumeni syndrome, defined by the presence of a pathogenic/likely pathogenic TP53 variant in a person/family with cancer who does not meet Li-Fraumeni syndrome testing criteria; and (4) incidental Li-Fraumeni syndrome, defined by the presence of a pathogenic/likely pathogenic TP53 variant in a person/family without a history of cancer. Data analysis occurred from November 2020 to March 2021.

Main Outcomes and Measures

Differences in variant distribution and cancer characteristics in patients with a germline TP53 variant who met vs did not meet Li-Fraumeni syndrome testing criteria.

Results

Tumor spectra showed significant differences, with more early adrenal (n = 166, 6.5% vs n = 0), brain (n = 360, 14.17% vs n = 57, 7.46%), connective tissue (n = 303, 11.92% vs n = 56, 7.33%), and bone tumors (n = 279, 10.98% vs n = 3, 0.39%) in patients who met Li-Fraumeni syndrome genetic testing criteria (n = 2139). Carriers who did not meet Li-Fraumeni syndrome genetic testing criteria (n = 678) had more breast (n = 292, 38.22% vs n = 700, 27.55%) and other cancers, 45% of them occurring after age 45 years. Hotspot variants were present in both groups. Several variants were exclusively found in patients with Li-Fraumeni syndrome, while others where exclusively found in patients with attenuated Li-Fraumeni syndrome. In patients who met Li-Fraumeni syndrome genetic testing criteria, most TP53 variants were classified as pathogenic/likely pathogenic (1757 of 2139, 82.2%), whereas 40.4% (404 of 678) of TP53 variants identified in patients who did not meet the Li-Fraumeni syndrome genetic testing criteria were classified as variants of uncertain significance, conflicting results, likely benign, benign, or unknown.

Conclusions and Relevance

The findings of this cohort study suggest that this new classification, Li-Fraumeni spectrum, is a step toward understanding the factors that lead to phenotypic differences and may serve as a model for other cancer predisposition syndromes.

Does awareness of condition help people with mild-to-moderate dementia to live well? Findings from the IDEAL programme

Background

People living with dementia vary in awareness of their abilities. We explored awareness of the condition and diagnosis in people with mild-to-moderate dementia, and how this relates to quality of life, well-being, life satisfaction, and caregiver stress.

Methods

This study was a cross-sectional exploratory analysis of data from the IDEAL cohort, which recruited people with dementia living at home and available caregivers from 29 research sites in Great Britain. Our study included 917 people with mild-to-moderate dementia and 755 carers. Low and high awareness groups were derived from self-reported responses to a dementia representation measure. Logistic regression was used to explore predictors of awareness of condition and diagnosis using demographic, cognitive, functional and psychological measures, and the relationship with quality of life, well-being and life satisfaction (‘living well’), and caregiver stress.

Results

There were 83 people with low awareness of their condition. The remaining 834 people showed some awareness and 103 of these had high awareness of their condition and diagnosis. Psychosocial factors were stronger predictors of awareness than cognitive and functional ability. Those with higher awareness reported lower mood, and lower scores on indices of living well as well as lower optimism, self-efficacy and self-esteem. Low awareness was more likely in those aged 80y and above, and living in more socially deprived areas. No relationship was seen between caregiver stress and awareness.

Conclusions

Awareness of the condition and diagnosis varies in people with mild-to-moderate dementia and is relevant to the capability to live well. Awareness should be considered in person-centered clinical care.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-021-02468-4.

Measuring Awareness in People With Dementia: Results of a Systematic Scoping Review

BACKGROUND

Awareness of the diagnosis or related changes in functioning varies in people with dementia (PwD), with implications for the well-being of PwD and their carers. Measuring awareness in a clinical setting could facilitate tailored support and optimize involvement in personal health and care decisions. This scoping review aimed to identify validated methods of assessing awareness in dementia and appraise their clinical utility.

METHOD

A systematic search was conducted of English-language publications that measured awareness in PwD, in 6 electronic databases. Search terms included dement*, Alzheimer*, Pick disease, and awareness, unawareness, anosognosia, insight, denial, metacognit*, or discrepanc*.

RESULTS

We screened 30,634 articles, finding 345 articles that met our inclusion criteria. We identified 76 measures, most commonly using a discrepancy questionnaire comparing evaluations of function by PwD and an informant. There were 30 awareness measures developed and validated for use in dementia populations but few designed for general clinical use.

CONCLUSIONS

Although we found a range of clinical indications for measuring awareness, there were few studies investigating clinical applications and few tools designed for clinical purposes. Further investigation and development of a person-centered tool could facilitate health and care choices in mild-to-moderate dementia.

Pathogenic germline IKZF1 variant alters hematopoietic gene expression profiles

IKZF1 encodes Ikaros, a zinc finger–containing transcription factor crucial to the development of the hematopoietic system. Germline pathogenic variants in IKZF1 have been reported in patients with acute lymphocytic leukemia and immunodeficiency syndromes. Diamond–Blackfan anemia (DBA) is a rare inherited bone marrow failure syndrome characterized by erythroid hypoplasia, associated with a spectrum of congenital anomalies and an elevated risk of certain cancers. DBA is usually caused by heterozygous pathogenic variants in genes that function in ribosomal biogenesis; however, in many cases the genetic etiology is unknown. We identified a germline IKZF1 variant, rs757907717 C > T, in identical twins with DBA-like features and autoimmune gastrointestinal disease. rs757907717 C > T results in a p.R381C amino acid change in the IKZF1 Ik-x isoform (p.R423C on isoform Ik-1), which we show is associated with altered global gene expression and perturbation of transcriptional networks involved in hematopoietic system development. These data suggest that this missense substitution caused a DBA-like syndrome in this family because of alterations in hematopoiesis, including dysregulation of networks essential for normal erythropoiesis and the immune system.

Alternative splicing is a developmental switch for hTERT expression

Telomere length control is critical for cellular lifespan and tumor suppression. Telomerase is transiently activated in the inner cell mass of the developing blastocyst to reset telomere reserves. Its silencing upon differentiation leads to gradual telomere shortening in somatic cells. Here, we report that transcriptional regulation through cis-regulatory elements only partially accounts for telomerase activation in pluripotent cells. Instead, developmental control of telomerase is primarily driven by an alternative splicing event, centered around hTERT exon 2. Skipping of exon 2 triggers hTERT mRNA decay in differentiated cells, and conversely, its retention promotes telomerase accumulation in pluripotent cells. We identify SON as a regulator of exon 2 alternative splicing and report a patient carrying a SON mutation and suffering from insufficient telomerase and short telomeres. In summary, our study highlights a critical role for hTERT alternative splicing in the developmental regulation of telomerase and implicates defective splicing in telomere biology disorders.

Gynaecological and reproductive health of women with telomere biology disorders

Reproductive health may be adversely impacted in women with dyskeratosis congenita (DC) and related telomere biology disorders (TBD). We evaluated gynaecological problems, fertility, and pregnancy outcomes in 39 females aged 10-81 years who were followed longitudinally in our DC/TBD cohort. Twenty-six had bone marrow failure and 12 underwent haematopoietic cell transplantation. All attained menarche at a normal age. Thirteen women reported menorrhagia; ten used hormonal contraception to reduce bleeding. Nine experienced natural normal-aged menopause. Gynaecological problems (endometriosis = 3, pelvic varicosities = 1, cervical intraepithelial neoplasia = 1, and uterine prolapse = 2) resulted in surgical menopause in seven. Twenty-five of 26 women attempting fertility carried 80 pregnancies with 49 (61%) resulting in livebirths. Ten (38%) women experienced 28 (35%) miscarriages, notably recurrent pregnancy loss in five (19%). Preeclampsia (n = 6, 24%) and progressive cytopenias (n = 10, 40%) resulted in maternal-fetal compromise, including preterm (n = 5) and caesarean deliveries (n = 18, 37%). Gynaecological/reproductive problems were noted mainly in women with autosomal-dominant inheritance; others were still young or died early. Although women with TBDs had normal menarche, fertility, and menopause, gynaecological problems and pregnancy complications leading to caesarean section, preterm delivery, or transfusion support were frequent. Women with TBDs will benefit from multidisciplinary, coordinated care by haematology, gynaecology and maternal-fetal medicine.

The causes of Fanconi anemia in South Asia and the Middle East: A case series and review of the literature

Background

Fanconi anemia (FA) is an inherited bone marrow failure syndrome associated with characteristic dysmorphology primarily caused by biallelic pathogenic germline variants in any of 22 different DNA repair genes. There are limited data on the specific molecular causes of FA in different ethnic groups.

Methods

We performed exome sequencing and copy number variant analyses on 19 patients with FA from 17 families undergoing hematopoietic cell transplantation evaluation in Pakistan. The scientific literature was reviewed, and we curated germline variants reported in patients with FA from South Asia and the Middle East.

Results

The genetic causes of FA were identified in 14 of the 17 families: seven FANCA, two FANCC, one FANCF, two FANCG, and two FANCL. Homozygous and compound heterozygous variants were present in 12 and two families, respectively. Nine families carried variants previously reported as pathogenic, including two families with the South Asian FANCL founder variant. We also identified five novel likely deleterious variants in FANCA, FANCF, and FANCG in affected patients.

Conclusions

Our study supports the importance of determining the genomic landscape of FA in diverse populations, in order to improve understanding of FA etiology and assist in the counseling of families.