The genomics of inherited bone marrow failure: from mechanism to the clinic

The inherited bone marrow failure syndromes (IBMFS) typically present with significant cytopenias in at least one haematopoietic cell lineage that may progress to pancytopenia, and are associated with increased risk of cancer. Although the clinical features of the IBMFS are often diagnostic, variable disease penetrance and expressivity may result in diagnostic dilemmas. The discovery of the genetic aetiology of the IBMFS has been greatly facilitated by next-generation sequencing methods. This has advanced understanding of the underlying biology of the IBMFS and been essential in improving clinical management and genetic counselling for affected patients. Herein we review the clinical features, underlying biology, and new genomic discoveries in the IBMFS, including Fanconi anaemia, dyskeratosis congenita, Diamond Blackfan anaemia, Shwachman Diamond syndrome and some disorders of the myeloid and megakaryocytic lineages.

Estimating TP53 Mutation Carrier Probability in Families with Li-Fraumeni Syndrome Using LFSPRO

Background: Li-Fraumeni syndrome (LFS) is associated with germline TP53 mutations and a very high lifetime cancer risk. Algorithms that assess a patient's risk of inherited cancer predisposition are often used in clinical counseling. The existing LFS criteria have limitations, suggesting the need for an advanced prediction tool to support clinical decision making for TP53 mutation testing and LFS management.Methods: Based on a Mendelian model, LFSPRO estimates TP53 mutation probability through the Elston-Stewart algorithm and consequently estimates future risk of cancer. With independent datasets of 1,353 tested individuals from 867 families, we evaluated the prediction performance of LFSPRO.Results: LFSPRO accurately predicted TP53 mutation carriers in a pediatric sarcoma cohort from MD Anderson Cancer Center in the United States, the observed to expected ratio (OE) = 1.35 (95% confidence interval, 0.99-1.80); area under the receiver operating characteristic curve (AUC) = 0.85 (0.75-0.93); a population-based sarcoma cohort from the International Sarcoma Kindred Study in Australia, OE = 1.62 (1.03-2.55); AUC = 0.67 (0.54-0.79); and the NCI LFS study cohort, OE = 1.28 (1.17-1.39); AUC = 0.82 (0.78-0.86). LFSPRO also showed higher sensitivity and specificity than the classic LFS and Chompret criteria. LFSPRO is freely available through the R packages LFSPRO and BayesMendel.Conclusions: LFSPRO shows good performance in predicting TP53 mutations in individuals and families in varied situations.Impact: LFSPRO is more broadly applicable than the current clinical criteria and may improve clinical management for individuals and families with LFS. Cancer Epidemiol Biomarkers Prev; 26(6); 837-44. ©2017 AACR.

Current Knowledge and Priorities for Future Research in Late Effects after Hematopoietic Cell Transplantation for Inherited Bone Marrow Failure Syndromes: Consensus Statement from the Second Pediatric Blood and Marrow Transplant Consortium International Conference on Late Effects after Pediatric Hematopoietic Cell Transplantation

Fanconi anemia (FA), dyskeratosis congenita (DC), and Diamond Blackfan anemia (DBA) are 3 of the most common inherited bone marrow failure syndromes (IBMFS), in which the hematologic manifestations can be cured with hematopoietic cell transplantation (HCT). Later in life, these patients face a variety of medical conditions, which may be a manifestation of underlying disease or due to pre-HCT therapy, the HCT, or a combination of all these elements. Very limited long-term follow-up data exist in these populations, with FA the only IBMFS that has specific published data. During the international consensus conference sponsored by the Pediatric Blood and Marrow Transplant Consortium entitled "Late Effects Screening and Recommendations following Allogeneic Hematopoietic Cell Transplant (HCT) for Immune Deficiency and Nonmalignant Hematologic Disease" held in Minneapolis, Minnesota in May of 2016, a half-day session was focused specifically on the unmet needs for these patients with IBMFS. A multidisciplinary group of experts discussed what is currently known, outlined an agenda for future research, and laid out long-term follow-up guidelines based on a combination of evidence in the literature as well as expert opinion. This article addresses the state of science in that area as well as consensus regarding the agenda for future research, with specific screening guidelines to follow in the next article from this group.

On the nose: Olfactory disturbances in patients with transient epileptic amnesia

OBJECTIVE

While olfactory hallucinations are relatively rare in epilepsy, a high prevalence (up to 42%) has been reported in one form - Transient Epileptic Amnesia (TEA). TEA is characterized by recurring amnestic seizures and is commonly associated with persistent interictal memory deficits. Despite reports of changes in smell, olfactory ability has not been objectively assessed in this group. The aim of this study was to measure olfactory ability in patients with TEA and explore whether olfactory symptoms relate to other clinical variables.

METHODS

Fifty-five participants with TEA were recruited from The Impairment of Memory in Epilepsy project database. The presence of olfactory symptoms was obtained via case notes and clinical interview. Participants completed questionnaires to evaluate their olfaction and memory function subjectively. Olfactory ability was measured using the University of Pennsylvania Smell Identification Test (UPSIT). TEA participants' performance was compared to 50 matched healthy control participants. A subset of TEA participants (n=26) also completed a battery of memory tests including standard neuropsychological measures, and assessment of accelerated long-term forgetting and autobiographical memory.

RESULTS

Olfactory hallucinations were reported in 55% of patients with TEA. A significant reduction in smell identification (UPSIT) was found between patients with TEA and healthy controls (p<0.001). Epilepsy variables, including history of olfactory hallucinations, were not predictive of olfactory ability. Patients reported ongoing memory difficulties and performed below normative values on objective tests. While no correlation was found between objective measures of memory and olfactory performance, subjective complaints of route finding difficulty was associated with UPSIT score.

CONCLUSIONS

Impairments in odor identification are common in patients with TEA and exceed changes that occur in normal aging. Olfactory hallucinations occurs in approximately half of patients with TEA, but do not always coincide with reduced sense of smell. Olfactory impairment and interictal memory problems both occur frequently in TEA but are not closely associated.

Risks of first and subsequent cancers among TP53 mutation carriers in the National Cancer Institute Li-Fraumeni syndrome cohort

BACKGROUND

Li-Fraumeni syndrome (LFS) is an autosomal dominant cancer predisposition syndrome characterized by a very high lifetime cancer risk and an early age at diagnosis of a wide cancer spectrum. Precise estimates for the risk of first and subsequent cancers are lacking.

METHODS

The National Cancer Institute's Li-Fraumeni Syndrome Study includes families meeting the diagnostic criteria for LFS or Li-Fraumeni-like syndrome, and individuals with a germline TP53 mutation, choroid plexus carcinoma, adrenocortical carcinoma, or ≥3 cancers. Herein, we estimated the cumulative risk and annual hazards for first and second cancers among TP53 mutation carriers (TP53 positive [TP53+]) using MATLAB statistical software.

RESULTS

This study evaluated 286 TP53+ individuals from 107 families. The cumulative cancer incidence was 50% by age 31 years among TP53+ females and 46 years among males, and nearly 100% by age 70 years for both sexes. Cancer risk was highest after age 20 years for females, mostly due to breast cancer, whereas among males the risk was higher in childhood and later adulthood. Among females, the cumulative incidence rates by age 70 years for breast cancer, soft tissue sarcoma, brain cancer, and osteosarcoma were 54%, 15%, 6%, and 5%, respectively. Among males, the incidence rates were 22%, 19%, and 11%, respectively, for soft tissue sarcoma, brain cancer, and osteosarcoma. Approximately 49% of those with 1 cancer developed at least another cancer after a median of 10 years. The average age-specific risk of developing a second cancer was comparable to that of developing a first cancer.

CONCLUSIONS

The cumulative cancer risk in TP53 + individuals was very high and varied by sex, age, and cancer type. Additional work, including prospective risk estimates, is needed to better inform personalized risk management. Cancer 2016;122:3673-81. © 2016 American Cancer Society.

Investigation of chromosome X inactivation and clinical phenotypes in female carriers of DKC1 mutations

Dyskeratosis congenita (DC) is an inherited bone marrow failure and cancer susceptibility syndrome caused by germline mutations in telomere biology genes. Germline mutations in DKC1, which encodes the protein dyskerin, cause X-linked recessive DC. Because of skewed X-chromosome inactivation, female DKC1 mutation carriers do not typically develop clinical features of DC. This study evaluated female DKC1 mutation carriers with DC-associated phenotypes to elucidate the molecular features of their mutations, in comparison with unaffected carriers and mutation-negative female controls. All female DKC1 mutation carriers had normal leukocyte subset telomere lengths and similarly skewed X-inactivation in multiple tissue types, regardless of phenotype. We observed dyskerin expression, telomerase RNA accumulation, and pseudouridylation present in all mutation carriers at levels comparable to healthy wild-type controls. Our study suggests that mechanisms in addition to X chromosome inactivation, such as germline mosaicism or epigenetics, may contribute to DC-like phenotypes present in female DKC1 mutation carriers. Future studies are warranted to understand the molecular mechanisms associated with the phenotypic variability in female DKC1 mutation carriers, and to identify those at risk of disease. Am. J. Hematol. 91:1215-1220, 2016. © 2016 Wiley Periodicals, Inc.

Inhibiting mitochondrial respiration prevents cancer in a mouse model of Li-Fraumeni syndrome

Li-Fraumeni syndrome (LFS) is a cancer predisposition disorder caused by germline mutations in TP53 that can lead to increased mitochondrial metabolism in patients. However, the implications of altered mitochondrial function for tumorigenesis in LFS are unclear. Here, we have reported that genetic or pharmacologic disruption of mitochondrial respiration improves cancer-free survival in a mouse model of LFS that expresses mutant p53. Mechanistically, inhibition of mitochondrial function increased autophagy and decreased the aberrant proliferation signaling caused by mutant p53. In a pilot study, LFS patients treated with metformin exhibited decreases in mitochondrial activity concomitant with activation of antiproliferation signaling, thus reproducing the effects of disrupting mitochondrial function observed in LFS mice. These observations indicate that a commonly prescribed diabetic medicine can restrain mitochondrial metabolism and tumorigenesis in an LFS model, supporting its further consideration for cancer prevention in LFS patients.

Transient Epileptic Amnesia over twenty years: Long-term follow-up of a case series with three detailed reports

Purpose

Transient Epileptic Amnesia (TEA) is a form of adult onset temporal lobe epilepsy characterised by ictal amnesia. The amnesic seizures are often accompanied by interical memory disturbance, involving autobiographical amnesia and accelerated long-term forgetting. Short-term follow-up studies suggest a relatively stable cognitive profile once treated, but recent case reports raise concerns regarding the risk of developing Alzheimer’s Disease (AD). The current study reports clinical and cognitive outcome in TEA patients over a 20-year period.

Methods

A cohort of ten TEA patients first reported in 1998 were followed up at two time intervals, each 10 years apart. Information regarding clinical outcomes and subjective reports of memory functioning was gained via GP records and clinical interview. Objective memory function was determined at each time point via a comprehensive neuropsychological assessment, where possible.

Results

Information was obtained for nine of the original 10 participants. Over the 20-year period, 4 participants died, with no indication of dementia prior to death. One participant was diagnosed with Vascular Dementia. Seizures were generally well controlled. Subjective reports of memory varied, including no concerns, stable memory difficulties, and worsening memory. Neuropsychological assessment at 10 years showed stable performances across most measures. At the 20-year follow up, there was no evidence of a general cognitive decline. Participants showed stability on some measures, with reductions on others. Performance was not consistent with AD.

Conclusions

No elevated risk of dementia was evident from this TEA series. Although memory difficulties persist over time, the prognosis of TEA appears generally benign.

Effect of Recipient Age and Stem Cell Source on the Association between Donor Telomere Length and Survival after Allogeneic Unrelated Hematopoietic Cell Transplantation for Severe Aplastic Anemia

We previously showed an association between donor leukocyte relative telomere length (RTL) and post-hematopoietic cell transplantation (HCT) survival in patients with severe aplastic anemia (SAA) who received bone marrow grafts at ages <40 years. Here, we tested the generalizability of the prior findings in an independent validation cohort and by recipient age and stem cell source in the combined discovery and validation cohorts. We used monoplex quantitative real-time PCR to measure RTL in: (1) a new SAA validation cohort of 428 patients (age range, .2 to 77 years) with available pretransplantation donor blood samples in the Center for International Blood and Marrow Transplant Research repository, and (2) 278 patients from the original cohort who had sufficient DNA to repeat RTL testing. We used Cox proportional hazard models to calculate hazard ratios (HRs), and 95% confidence intervals (CIs) across categories of donor RTL. Data from the validation cohort showed no association between donor RTL and patient survival, but further analysis identified differences by recipient age and stem cell source as the likely explanation. In patients <40 years, the HR comparing longest with shortest and middle RTL tertiles = .75; 95% CI,  .44 to 1.30 versus HR = 1.05; 95% CI, .59 to 1.89 for patients ≥40 years, P interaction = .37. In bone marrow recipients, the HR = .68; 95% CI, .72 to 1.10 versus HR = 1.29; 95% CI, .64 to 2.62 for peripheral blood stem cell grafts; P interaction = .88. Analyses using data from the 2 cohorts showed a statistically significant survival benefit only in <40-year-old patients receiving bone marrow graft (HR comparing longest and middle RTL tertiles with shortest = .69; 95% CI, .50 to .95, P = .02). The study suggested that the association between donor RTL and post-HCT outcomes in recipients with SAA may vary by recipient age and stem cell source. A larger study is needed to account for multiple comparisons and to further test the generalizability of our findings.

Relationship between plasma 25-hydroxyvitamin D and leucocyte telomere length by sex and race in a US study

A few studies have examined the association between vitamin D and telomere length, and fewer still have examined the relationship in black or male populations. We investigated the cross-sectional association between the vitamin D metabolite 25-hydroxyvitamin D (25(OH)D) concentration in plasma and relative leucocyte telomere length (LTL) in 1154 US radiologic technologists who were 48-93 years old (373 white females, 278 white males, 338 black females, 165 black males). Plasma 25(OH)D concentration was measured by the chemiluminescence immunoassay, and relative LTL was measured by quantitative PCR. Logistic regression was used to obtain OR and 95 % CI for long v. short (based on median) LTL in relation to continuous 25(OH)D, quartiles of 25(OH)D and 25(OH)D deficiency. We found no significant association between continuous 25(OH)D and long LTL in all participants (P trend=0·440), nor in white females (P trend=0·845), white males (P trend=0·636), black females (P trend=0·967) or black males (P trend=0·484). Vitamin D deficiency (defined as 25(OH)D<30 nmol/l), however, was significantly associated with short LTL in whites (P=0·024), but not in other groups. In this population, we found little evidence to support associations between 25(OH)D and long LTL over the entire range of 25(OH)D in the overall study population or by sex and race.

Abstract CT156: Safety and tolerability of metformin for chemoprevention in Li-Fraumeni syndrome (LFS)

Background: Metformin is FDA approved for the treatment of type II diabetes. Frequently reported side effects of metformin use in diabetics are abdominal cramping, nausea, and diarrhea. Lactic acidosis, a life-threatening accumulation of lactic acid in the blood, is also a potential adverse effect of metformin. The primary goal of this phase I study was to assess the safety and tolerability of metformin in non-diabetic patients with germline mutations in TP53 and a clinical diagnosis of LFS. LFS is a highly-penetrant, autosomal dominant, cancer predisposition disorder characterized by early onset of breast, sarcoma, adrenocortical, brain, and other cancers. Further, LFS patients have been shown to have increased oxidative phosphorylation capacity in skeletal muscle and oxidative stress markers. Evidence suggests metformin inhibits oxidative phosphorylation in mitochondria, reducing available energy for cancer cell proliferation, and decreasing the production of reactive oxygen species that can cause DNA damage. Although metformin is used safely in non-diabetic individuals for off -label indications such as polycystic ovarian syndrome and infertility, its use in non-diabetic patients with germline TP53 mutations has never been documented.

Objectives: To assess safety and tolerability of metformin dosages from 500 mg to 2000 mg per day in patients with germline mutations in TP53 and a clinical diagnosis of LFS.

Methodology: Adult LFS patients (?18 years old) with documented germline mutation in TP53 were enrolled for 20 weeks. Patients with a history of cancer had to be in remission (surgery and chemotherapy completed 6 and 12 months prior respectively). Patients could not have a history of diabetes or prior metformin use. Metformin was initiated at 500 mg per day and increased in 500 mg dose increments every two weeks to a maximum dose of 2000 mg by week 8. Patients were maintained on 2000 mg of metformin for six additional weeks (week 14). For the last six weeks of the study, patients were taken off metformin (week 20). The targeted accrual goal was ?22 subjects.

Results: Of 24 non-diabetic, LFS patients enrolled, 18 (75%) were female, and 6 (25%) were male. Thirteen (54%) females and 1 male (16%) had a prior history of cancer. The age range for females and males was 25-52 and 20-54 years old respectively. One patient developed cancer, and 2 withdrew from the study before starting treatment; 1 dropped out of the study due to personal issues after reaching a dose of 1500 mg. Of the remaining 20 patients, 1 dropped out of the study due to intolerable dyspepsia/reflux at a dose of 500 mg and 1 patient could only tolerate a maximum dose of 1500 mg due to headaches and nausea; the remaining 18 patients tolerated 2000 mg of metformin. Of 22 patients who took metformin, 20 (90%) experienced abdominal pain/nausea/diarrhea. Five patients (22%) experienced headaches. Three patients (13%) experienced reflux/dyspepsia. Two patients experienced one episode of vomiting (9%). None of the patients experienced lactic acidosis. Fasting glucose at week 14 on 2000 mg of metformin daily for females ranged from 76-96 mg/dL and for males 86-98 mg/dL.

Conclusions: Metformin was safe and tolerable in non-diabetic LFS patients with germline mutations in TP53. LFS patients report similar side effects as diabetic patients on metformin. No cases of lactic acidosis occurred.

Citation Format: Farzana Lukmanji Walcott, Paul M. Hwang, Ping-yuan Wang, Sharon A. Savage, Phuong Mai, Seth M. Steinberg, Michael N. Pollak, Christina Annunziata, Antonio T. Fojo. Safety and tolerability of metformin for chemoprevention in Li-Fraumeni syndrome (LFS). [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr CT156.

Abstract 3473: Psychosocial functioning in research participants at enrollment in a Li-Fraumeni syndrome study

Background: Li Fraumeni Syndrome (LFS) is an autosomal dominant cancer predisposition syndrome in which about 90% of individuals develop cancer by age 60. Approximately 70% of individuals with LFS have germline TP53 mutation. We hypothesized that this high level of cancer risk may be associated with increased emotional distress, cancer risk perceptions and cancer worry in individuals from LFS families.

Methods: Data from 276 adult (≥18 years old) TP53 mutation carriers (TP53+), mutation negative (TP53-) and untested (UT) participants enrolled in an IRB-approved study at the Clinical Genetics Branch, NCI were obtained between January 2011 and June 2014.. Using questionnaires at baseline, we assessed emotional distress (global distress, somatization, anxiety and depression) as measured by the BSI-18, cancer risk perceptions (comparative: scores 1-5; 1 = much less than other people your age to 5 = much more than other people your age and absolute: 10-point scale; 1 = no chance; 5 = may or may not; 10 = almost certainly) and cancer worry scales (frequency of cancer thoughts, interference with mood and daily activity, scores 1-4; = not at all or rarely to 4 = several times a day).

Results: TP53+ estimated their comparative lifetime risk of cancer as higher than TP53- and UT; [4.9 (SD = 0.5) vs. 3.8 (SD = 1) and 3.2 (SD = 1.3) p&lt;0.01], respectively]. TP53+ also estimated their absolute cancer risk as significantly higher than TP53- and UT on a [8.6(SD = 1.5) vs. 6.3 (SD = 1.6) and 5.7 (SD = 2.1), p&lt;0.01].Cancer worry was higher in TP53+ than TP53-or UT. TP53+ also indicated they thought about their cancer risk more frequently thanTP53- and UT [2.3 (SD = 0.9) vs. 1.3 (0.6) and 1.3 (SD = 0.6), p&lt;0.01]. There was a small but statistically significant difference between TP53+, TP53- and UT in their appraisal of whether cancer worry affected their mood over the past month [1.6 (SD = 0.6) vs. 1.2 (SD = 0.6) and 1.1 (SD = 0.2), p = &lt;0.01] and whether thoughts of cancer affected their ability to perform daily activities [1.2 (SD = 0) vs. 1.1 (SD = 0.4) and 1 (SD = 0.2), p = &lt;0.01]. No statistically significant differences were observed on measures of emotional distress between TP53+, TP53- or UT somatization [46.7 (SD = 8.1) vs. 45.9 (SD = 9.3) and 45.9 (SD = 7.6); depression [50.1 (SD 9.7) vs. 49.6 (SD - 9.3) and 45.9 (SD = 7.6); anxiety [48.2 (SD = 9.1) vs. 45.4 (SD = 9.7) and 45.8 (SD = 7.9) or global distress [47.9(SD = 9.9); vs. 45.1(12.1) and 44.9 (SD = 9.5)].

Conclusions: Participants in the LFSS do not demonstrate high levels of emotional distress. TP53+ appropriately identify their comparative and absolute cancer risk as high, but have levels of cancer worry that appears to be only slightly affecting their mood or ability to perform daily activities. Future research will focus on longitudinal changes in risk perception, cancer worry and emotional well-being while enrolled in a cancer screening study.

Citation Format: Jennifer T. Loud, Renee C. Bremer, Rosamma Decastro, June A. Peters, Phuong L. Mai, Sharon A. Savage. Psychosocial functioning in research participants at enrollment in a Li-Fraumeni syndrome study. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3473.

"Knowing What You Don't Know": Language Insight in Semantic Dementia

BACKGROUND

Reduced insight commonly occurs in dementia and can be specific to one area of functioning. Despite recent models identifying a role for semantic memory, little investigation of insight has been conducted in semantic dementia (SD), with patients often described as being aware of their language problems.

OBJECTIVE

This study aims to investigate language insight in SD.

METHOD

Twenty-two SD (n = 11 severe, n = 11 mild-moderate) and 9 nonfluent primary progressive aphasic patients completed three experimental language tasks to assess knowledge and awareness of certain words. Skills in evaluating language were tested by comparing performance ratings on the Cookie Theft task with objective scoring. Awareness regarding the existence and previous use of certain words was tested using two additional tasks.

RESULTS

While SD patients were as accurate as nonfluent patients in rating their own performance on the Cookie Theft immediately following the task, they were significantly poorer at evaluating the same content re-recorded, or other examples of poor language. Compared to nonfluent patients, severe SD patients also made more errors identifying previously known low frequency words. Lastly, when tested on labels for specific aspects of an object, only SD patients made errors regarding the existence, or their past knowledge, of certain words.

CONCLUSION

SD patients show a general awareness of their language impairments, but have difficulty evaluating language content. These difficulties adversely affect the ability to reflect upon current and past language skills producing an under-awareness of language deficits. This mild, secondary form of anosognosia appears to increase with greater levels of semantic impairment.

Female chromosome X mosaicism is age-related and preferentially affects the inactivated X chromosome

To investigate large structural clonal mosaicism of chromosome X, we analysed the SNP microarray intensity data of 38,303 women from cancer genome-wide association studies (20,878 cases and 17,425 controls) and detected 124 mosaic X events >2 Mb in 97 (0.25%) women. Here we show rates for X-chromosome mosaicism are four times higher than mean autosomal rates; X mosaic events more often include the entire chromosome and participants with X events more likely harbour autosomal mosaic events. X mosaicism frequency increases with age (0.11% in 50-year olds; 0.45% in 75-year olds), as reported for Y and autosomes. Methylation array analyses of 33 women with X mosaicism indicate events preferentially involve the inactive X chromosome. Our results provide further evidence that the sex chromosomes undergo mosaic events more frequently than autosomes, which could have implications for understanding the underlying mechanisms of mosaic events and their possible contribution to risk for chronic diseases.

Thinking outside the box: re-evaluating the approach to penetrating cardiac injuries

INTRODUCTION

Penetrating cardiac injuries are infrequent but highly lethal. To address these injuries, cardiopulmonary bypass and cardiothoracic surgery availability are required for Level I trauma center verification. However, acute care surgeons are more readily available for this time-sensitive injury. The purpose of this study was to review an acute care surgery-based experience with penetrating cardiac trauma at an urban Level 1 trauma center. Our hypothesis was that care provided solely by acute care surgeons was both safe and effective for this patient population.

METHODS

All patients with injuries to the 'cardiac box' following penetrating thoracic trauma were identified from 2005-2010. Demographic and injury related data were obtained. The types and location of cardiac injury, as well as patient outcomes, were determined from operative reports.

RESULTS

1701 patients with penetrating chest trauma were admitted during the study period. 260 patients were identified as having high-risk injuries and were included in the review. 37 patients underwent resuscitative thoracotomy, with a survival rate of 8 %. 76 patients (29 %) suffered a cardiac injury. 72 % of these patients had a preoperative FAST exam, which had a sensitivity and specificity of 56.5 and 82.5 % respectively. 82 % underwent a pericardial window, which had a positive predictive value of 81.4 %. 61 % (n = 46) of the patients with a cardiac injury survived, while the overall death rate in this cohort was 21 %. No patients in the cohort required cardiopulmonary bypass for emergent repair of cardiac injury and acute care surgeons performed all cases.

CONCLUSION

Penetrating injury to the heart is highly lethal and time-sensitive. Increasingly, FAST and subxyphoid pericardial window are relied upon to make the diagnosis in patients arriving in varying stages of shock to the resuscitation room. Acute care surgeons are the most appropriate surgeons to care for these injuries and provide safe and effective care.

The shelterin complex and hematopoiesis

Mammalian chromosomes terminate in stretches of repetitive telomeric DNA that act as buffers to avoid loss of essential genetic information during end-replication. A multiprotein complex known as shelterin prevents recognition of telomeric sequences as sites of DNA damage. Telomere erosion contributes to human diseases ranging from BM failure to premature aging syndromes and cancer. The role of shelterin telomere protection is less understood. Mutations in genes encoding the shelterin proteins TRF1-interacting nuclear factor 2 (TIN2) and adrenocortical dysplasia homolog (ACD) were identified in dyskeratosis congenita, a syndrome characterized by somatic stem cell dysfunction in multiple organs leading to BM failure and other pleiotropic manifestations. Here, we introduce the biochemical features and in vivo effects of individual shelterin proteins, discuss shelterin functions in hematopoiesis, and review emerging knowledge implicating the shelterin complex in hematological disorders.

Research participant interest in primary, secondary, and incidental genomic findings

PURPOSE

To define the frequency with which adult research participants consent to be offered clinically validated research genetic test results (RR) and incidental findings (IF).

METHODS

Consents were obtained from 506 adults enrolled in one of three studies within the National Cancer Institute Clinical Genetics Branch's Familial Cancer Research Program. A cross-sectional analysis was performed involving the choices indicated on study consents regarding receipt of RR and IF.

RESULTS

Ninety-seven percent opted to receive RR and IF. Participants who declined (n = 16) included two cancer survivors who were mutation-positive (1 = RR and 1 = both), eight who knew their primary mutation status (3 = RR; 4 = IF; 1 = both), three nonbloodline relatives (1 = RR; 2 = both), one untested but with the syndromic phenotype (1 = IF), and two parents of an affected child (2 = both). We speculate that these individuals either already had sufficient information, were not prepared to learn more, or felt that the information would not change their personal health-care decision making.

CONCLUSIONS

Adult research participants from families at high genetic risk for cancer overwhelmingly indicated their preference to receive both RR and IF. Future research will seek to identify the reasons for declining RR and IF and to study the impact of receipt of RR and IF on personal medical decision making.Genet Med 18 12, 1218-1225.

Current state of pediatric sarcoma biology and opportunities for future discovery: A report from the sarcoma translational research workshop

Sarcomas are a rare subgroup of pediatric cancers comprised of a variety of bone and soft-tissue tumors. While significant advances have been made in improving outcomes of patients with localized pediatric sarcomas since the addition of systemic chemotherapy to local control many decades ago, outcomes for patients with metastatic and relapsed sarcoma remain poor with few novel therapeutics identified to date. With the advent of new technologies to study cancer genomes, transcriptomes and epigenomes, our understanding of sarcoma biology has improved tremendously in a relatively short period of time. However, much remains to be accomplished in this arena especially with regard to translating all of this new knowledge to the bedside. To this end, a meeting was convened in Philadelphia, PA, on April 18, 2015 sponsored by the QuadW foundation, Children's Oncology Group and CureSearch for Children's Cancer that brought together sarcoma clinicians and scientists from North America to review the current state of pediatric sarcoma biology and ongoing/planned genomics based clinical trials in an effort to identify and bridge knowledge gaps that continue to exist at present. At the conclusion of the workshop, three key objectives that would significantly further our understanding of sarcoma were identified and a proposal was put forward to develop an all-encompassing pediatric sarcoma biology protocol that would address these specific needs. This review summarizes the proceedings of the workshop.

The limitations of qPCR telomere length measurement in diagnosing dyskeratosis congenita

Background

Telomere length <1st percentile‐for‐age in leukocyte subsets by flow cytometry with fluorescence in situ hybridization (flow FISH) is highly sensitive and specific in diagnosing patients with dyskeratosis congenita (DC), a telomere biology disorder.

Methods

We evaluated the clinical utility of the high‐throughput quantitative real‐time PCR (qPCR) relative telomere length (RTL) measurement as a diagnostic test for DC in patients with a priori clinical and/or genetic DC diagnoses. We calculated the sensitivity and specificity of RTL at different age‐specific percentile cutoffs in 31 patients with DC and 51 mutation‐negative relatives, and evaluated RTL difference by disease genotype.

Results

qPCR RTL <1st percentile‐for‐age failed to identify more than 60% of the patients already known to have DC (sensitivity = 39%, specificity = 98%). Three‐quarters of DC patients had RTL below the 10th percentile‐for‐age (sensitivity = 74%), as did 12% of the unaffected relatives (specificity = 88%).

Conclusions

Our findings suggest that the qPCR RTL method is not optimal for diagnosing DC. In light of these limitations, leukocyte flow FISH telomere length remains the recommended molecular test for diagnosing DC.

Hoyeraal-Hreidarsson Syndrome due to PARN Mutations: Fourteen Years of Follow-Up

BACKGROUND

Hoyeraal-Hreidarsson syndrome is a dyskeratosis congenita-related telomere biology disorder that presents in infancy with intrauterine growth retardation, immunodeficiency, and cerebellar hypoplasia in addition to the triad of nail dysplasia, skin pigmentation, and oral leukoplakia. Individuals with Hoyeraal-Hreidarsson syndrome often develop bone marrow failure in early childhood. Germline mutations in DKC1, TERT, TINF2, RTEL1, ACD, or PARN cause about 60% of individuals with Hoyeraal-Hreidarsson syndrome.

PATIENT DESCRIPTION

We describe 14 years of follow-up of an individual with Hoyeraal-Hreidarsson syndrome who initially presented as an infant with intrauterine growth retardation, microcephaly, and central nervous system calcifications. He was diagnosed with Hoyeraal-Hreidarsson syndrome at age 6 years and had a complicated medical history including severe developmental delay, cerebellar hypoplasia, esophageal and urethral stenosis, hip avascular necrosis, immunodeficiency, and bone marrow failure evolving to myelodysplastic syndrome requiring hematopoietic cell transplantation at age 14 years. He had progressive skin pigmentation, oral leukoplakia, and nail dysplasia leading to anonychia. Whole exome sequencing identified novel biallelic variants in PARN.

CONCLUSIONS

This patient illustrates that the constellation of intrauterine growth retardation, central nervous system calcifications, and cerebellar hypoplasia, esophageal or urethral stenosis, and cytopenias, in the absence of congenital infection, may be due to Hoyeraal-Hreidarsson syndrome. Early diagnosis of Hoyeraal-Hreidarsson syndrome is important to optimize medical management and provide genetic counseling.

Neonatal manifestations of inherited bone marrow failure syndromes

The inherited bone marrow failure syndromes (IBMFS) are a rare yet clinically important cause of neonatal hematological and non-hematological manifestations. Many of these syndromes, such as Fanconi anemia, dyskeratosis congenita and Diamond-Blackfan anemia, confer risks of multiple medical complications later in life, including an increased risk of cancer. Some IBMFS may present with cytopenias in the neonatal period whereas others may present only with congenital physical abnormalities and progress to pancytopenia later in life. A thorough family history and detailed physical examination are integral to the work-up of any neonate in whom there is a high index of suspicion for an IBMFS. Correct detection and diagnosis of these disorders is important for appropriate long-term medical surveillance and counseling not only for the patient but also for appropriate genetic counselling of their families regarding recurrence risks in future children and generations.

Analysis of Heritability and Shared Heritability Based on Genome-Wide Association Studies for Thirteen Cancer Types

BACKGROUND

Studies of related individuals have consistently demonstrated notable familial aggregation of cancer. We aim to estimate the heritability and genetic correlation attributable to the additive effects of common single-nucleotide polymorphisms (SNPs) for cancer at 13 anatomical sites.

METHODS

Between 2007 and 2014, the US National Cancer Institute has generated data from genome-wide association studies (GWAS) for 49 492 cancer case patients and 34 131 control patients. We apply novel mixed model methodology (GCTA) to this GWAS data to estimate the heritability of individual cancers, as well as the proportion of heritability attributable to cigarette smoking in smoking-related cancers, and the genetic correlation between pairs of cancers.

RESULTS

GWAS heritability was statistically significant at nearly all sites, with the estimates of array-based heritability, hl (2), on the liability threshold (LT) scale ranging from 0.05 to 0.38. Estimating the combined heritability of multiple smoking characteristics, we calculate that at least 24% (95% confidence interval [CI] = 14% to 37%) and 7% (95% CI = 4% to 11%) of the heritability for lung and bladder cancer, respectively, can be attributed to genetic determinants of smoking. Most pairs of cancers studied did not show evidence of strong genetic correlation. We found only four pairs of cancers with marginally statistically significant correlations, specifically kidney and testes (ρ = 0.73, SE = 0.28), diffuse large B-cell lymphoma (DLBCL) and pediatric osteosarcoma (ρ = 0.53, SE = 0.21), DLBCL and chronic lymphocytic leukemia (CLL) (ρ = 0.51, SE =0.18), and bladder and lung (ρ = 0.35, SE = 0.14). Correlation analysis also indicates that the genetic architecture of lung cancer differs between a smoking population of European ancestry and a nonsmoking Asian population, allowing for the possibility that the genetic etiology for the same disease can vary by population and environmental exposures.

CONCLUSION

Our results provide important insights into the genetic architecture of cancers and suggest new avenues for investigation.