Implications For Genetic Counseling Research Articles

Werner Syndrome

A 36-year-old male presented with young-onset diabetes and advanced peripheral vascular disease. He had a history of bilateral juvenile cataracts and premature aged appearance. Closer scrutiny unraveled multiple endocrine and nonendocrine abnormalities. Genetic studies revealed a novel pathogenic variant (homozygous c.3233+2T>c) confirming and expanding the mutation spectrum of Werner syndrome. This report highlights the need for precise diagnosis, which has important implications for prognosis and genetic counseling.

FTD-PSP is an Unusual Clinical Phenotype in A Frontotemporal Dementia Patient with A Novel Progranulin Mutation.

Progranulin (GRN) mutations are a major cause of frontotemporal dementia (FTD); the spectrum of clinical phenotypes of FTD is much more extensive than previously reported. The frequency and locations of GRN mutations in Chinese patients with FTD remain uncertain. We performed cDNA sequencing in one sporadic male patient who initially presented FTD symptoms. Brain magnetic resonance imaging (MRI) and positron emission computed tomography/computed tomography (PET/CT) were applied to further confirm the diagnosis of FTD from this patient. Cellular apoptosis and survival test were performed to identify the function of GRN. We identified one novel missense GRN mutation (c.1498G>A, p.V500I) in this patient, who initially presented typical behavioral-variant frontotemporal dementia (bvFTD) features but then presented progressive supranuclear palsy (PSP) clinical characteristics 5 years after onset. Besides, WT GRN protein showed an adequate trophic stimulus to preserve the survival of SH-SY5Y cells in the medium free of serum, while GRN mutation (c.1498G>A, p.V500I) may impair the ability of supporting cell survival. This study owns significant implications for genetic counseling and clinical heterogeneity. We illustrate the fact that FTD presenting features of bvFTD and PSP in one patient could be considered as a specific phenotype in patients with GRN mutations. GRN p.V500I led to the neuronal degeneration in vitro; this finding provides a significant evidence that this mutation may be a new causative mutation in patients with FTD.

Auditory Neuropathy Spectrum Disorder (ANSD)-Clinical Characteristics and Pathogenic Variant Analysis of Three Nonsyndromic Deafness Families.

Objective To analyze the phenotypic features and pathogenic variants of three unrelated families presenting with nonsyndromic auditory neuropathy spectrum disorder (ANSD). Methods Three recruited families that were affected by congenital deafness were clinically evaluated, including a detailed family history and audiological and radiological examination. The peripheral blood of all patients and their parents was collected for DNA extraction, and then, the exonic and flanking regions were enriched and sequenced using targeted capture and high-throughput sequencing technology. Bioinformatics analyses and the Sanger sequencing were carried out to screen and validate candidate pathogenic variants. The pathogenicity of candidate variants was evaluated by an approach that was based on the standards and guidelines for interpreting genetic variants as proposed by the American College of Medical Genetics and Genomics (ACMG). Results Four patients in three families were diagnosed as nonsyndromic ANSD, and all exhibited OTOF gene mutations. Among them, two individuals in family 1 (i.e., fam 1-II-2 and fam 1-II-3) carried homozygous variants c.[2688del];[2688del] (NM_194248.3). Two individuals from family 2 (fam 2-II-1) and family 3 (fam 3-II-4) carried compound heterozygous variants c.[4960G>A];[1469C>G] and c.[2675A>G];[2977_2978del], respectively. Conclusions Three unrelated pedigrees with ANSD were caused by pathogenic variants in the OTOF gene. Five mutations were found and included c.2688del, c.2675A>G, c.2977_2978del, c.4960G>A, and c.1469C>G, of which the first two are novel and expanded mutational spectrum of the OTOF gene, thus having important implications for genetic counseling of the family.

The Expanding Phenotypic Spectrums Associated with ATP1A3 Mutation in a Family with Rapid-Onset Dystonia Parkinsonism

Introduction: Rapid-onset dystonia parkinsonism (RDP), also referred to as Dystonia 12, is a rare autosomal dominant genetic disease characterized by abrupt onset of a rostrocaudal gradient of dystonia with prominent bulbar symptoms, and parkinsonian features, primarily bradykinesia and postural instability without tremor. The purpose of this study was to identify the genetic defect in a Chinese pedigree with familial RDP and to explore genotype-phenotype correlation. Methods: A 3-generation Chinese Han pedigree consisting of 9 members and 3 patients with RDP, and 200 unrelated ethnically matched normal subjects were recruited in this study. Exome sequencing was performed in the proband, and Sanger sequencing was then conducted in other family members and 200 normal controls. Results: In addition to the typical clinical manifestations of RDP, the proband and her sister presented tongue tremor which developed at the onset, and intriguingly the proband showed a “re-emergent” tongue tremor. Both the proband and her sister had a medical history of hyperthyroidism, and at the psychiatric interview they both received diagnoses of depression and anxiety. Excessive grammar errors existed in most sentences written by the proband, and this written-expression disorder occurred years before the onset of RDP. The mother of the proband presented tongue enlargement, oromandibular dystonia, and limb dystonia, which were not observed in her 2 daughters at the time of study. A missense variant, c.1838C>T (p.T613M), in the ATP1A3 gene, was identified in the 3 patients in the family and in 2 young children but was absent in family members without RDP and in the 200 normal controls. Conclusion: These findings may broaden the phenotypic spectrums of RDP with mutations in the ATP1A3 gene, provide new insights into the diagnosis of RDP, and have implications for genetic counseling.

The Importance of Autopsy in Early Neonatal Death in Portugal

The early neonatal period is the most critical for the newborn's life. The autopsy is important to understand the cause of death, and find other diagnoses not clinically identified. However, the rate of neonatal autopsy is declining worldwide. This study aims to characterize early neonatal death and the clinical importance of the autopsy, evaluating the concordance between clinical and pathological diagnosis. Retrospective study of the clinical records of all neonates admitted to a level III Neonatal Intensive Care unit in Portugal who died during the first week of life in 10 consecutive years (2008 - 2017). In order to classify the concordance found between clinical and pathological diagnoses, the modified Goldman classification was used. During the first week of life, 76 newborns died. The main causes of death were complications related with prematurity and congenital malformations. The autopsy was performed in 50 newborns. Additional findings were found in 62% of the cases, and in 12% findings with important implications for genetic counseling of future pregnancies. There was concordance between the clinical and pathological findings in 38% of cases. An autopsy was performed more frequently in newborns with greater gestational age. The number of additional diagnoses found at autopsy, including diagnoses with implications for genetic counseling, confirm the importance of performing them. An autopsy should be proposed to all parents after early neonatal death, given its importance in clarifying the cause of death.

Preferential Maternal Transmission of STX16-GNAS Mutations Responsible for Autosomal Dominant Pseudohypoparathyroidism Type Ib (PHP1B): Another Example of Transmission Ratio Distortion.

Preferential transmission of a genetic mutation to the next generation, referred to as transmission ratio distortion (TRD), is well established for several dominant disorders, but underlying mechanisms remain undefined. Recently, TRD was reported for patients affected by pseudohypoparathyroidism type Ia or pseudopseudohypoparathyroidism. To determine whether TRD is observed also for autosomal dominant pseudohypoparathyroidism type Ib (AD-PHP1B), we analyzed kindreds with the frequent 3-kb STX16 deletion or other STX16/GNAS mutations. If inherited from a female, these genetic defects lead to loss-of-methylation at exon A/B alone or at all three differentially methylated regions (DMR), resulting in parathyroid hormone (PTH)-resistant hypocalcemia and hyperphosphatemia and possibly resistance to other hormones. In total, we investigated 212 children born to 80 females who are unaffected carriers of a STX16/GNAS mutation (n = 47) or affected by PHP1B (n = 33). Of these offspring, 134 (63.2%) had inherited the genetic defect (p = .00012). TRD was indistinguishable for mothers with a STX16/GNAS mutation on their paternal (unaffected carriers) or maternal allele (affected). The mechanisms favoring transmission of the mutant allele remain undefined but are likely to include abnormalities in oocyte maturation. Search for mutations in available descendants of males revealed marginally significant evidence for TRD (p = .038), but these analyses are less reliable because many more offspring of males than females with a STX16/GNAS mutation were lost to follow-up (31 of 98 versus 6 of 218). This difference in follow-up is probably related to the fact that inheritance of a mutation from a male does not have clinical implications, whereas inheritance from an affected or unaffected female results in PHP1B. Lastly, affected PHP1B females had fewer descendants than unaffected carriers, but it remains unclear whether abnormal oocyte development or impaired actions of reproductive hormones are responsible. Our findings highlight previously not recognized aspects of AD-PHP1B that are likely to have implications for genetic testing and counseling. © 2020 American Society for Bone and Mineral Research (ASBMR).

KLF13 loss-of-function variation contributes to familial congenital heart defects.

Congenital heart defect (CHD) represents the most common form of human developmental abnormality and contributes to substantial morbidity, mortality, and socioeconomic burden worldwide. Accumulating evidence underscores the strong genetic basis of CHD. Nevertheless, CHD is of pronounced genetic heterogeneity, and the genetic determinants underlying CHD in most patients are still unclear. This study was mainly sought to identify the causative gene for CHD in a consanguineous Chinese family. Whole-exosome sequencing and bioinformatics analyses were performed in a Chinese family with CHD (double-outlet right ventricle and ventricular septal defect), which was transmitted in an autosomal dominant pattern. A total of 312 unrelated healthy individuals were then genotyped for the identified genetic variation. The functional effect of the identified variation was characterized by utilizing a Dual-Luciferase reporter assay system. A novel heterozygous variation, NM_015995.3: c.370G>T; p.(Glu124*), was identified in the KLF13 gene, which encodes Kruppel-like factor 13 key to proper heart development. Genetic analysis of the pedigree unveiled that the variation co-segregated with CHD, with complete penetrance. The variation was absent from 624 control chromosomes. The biological analysis revealed that the Glu124*-mutant KLF13 protein failed to transactivate its cardiac target genes ACTC1 and ANP. Furthermore, the variation disrupted the synergistic transactivation between KLF13 and GATA4, as well as GATA6, two other genes that have been recognized to cause CHD. These findings firstly indicate that genetically defective KLF13 predisposes to familial CHD, implying potential implications for genetic counseling and an improved prophylactic strategy in a subset of CHD patients.

Novel compound heterozygous variants in the STIL gene identified in a Chinese family with presentation of foetal microcephaly

Primary microcephaly 7 (MCPH7) is an autosomal recessive human neurodevelopmental disorder characterized by microcephaly, sloping forehead, and prominent midface. The STIL gene encodes a protein that regulates the mitotic spindle checkpoint. STIL is the pathogenic gene of MCPH7. Although more than 25 genes have been reported to cause MCPH, many patients lack a molecular diagnosis. The clinical manifestations and genetic factors of MCPH7 remain to be revealed. This research reported two consecutive microcephalic foetuses from unaffected parents. Prenatal ultrasound examination and pre- and postnatal MRI studies were performed. Whole-genome sequencing (WGS) was performed using blood derived from the umbilical cord, and variants were confirmed by Sanger sequencing on the parents. Ultrasound examination showed that the two foetuses suffered primary microcephaly. Using the WGS approach, novel compound heterozygous variants in STIL (c.2344_2347delTTGC, p. Leu782Thrfs*2 in exon 13; c.3838C > T, p. Arg1280Cys in exon 17) were identified in two foetuses with MCPH7. The MRI results of the two siblings were quite similar. Postnatal MRI confirmed the ultrasound and prenatal examinations. The two foetuses had typical microcephaly. Ultrasound and MRI showed that the two foetuses had a thick skull plate, significantly reduced bilateral frontal lobe, upward rotated cerebellum vermis, and dilated fourth ventricle. Our findings have important implications for prenatal diagnosis and genetic counselling for any patients with MCPH7. We extend both the mutational spectrum in the STIL gene and the clinical spectrum of MCPH7.

PAX6 missense variants in two families with isolated foveal hypoplasia and nystagmus: evidence of paternal postzygotic mosaicism

PAX6 is considered the master regulator of eye development, the majority of variants affecting this gene cause the pan-ocular developmental eye disorder aniridia. Although no genotype-phenotype correlations are clearly established, missense variants affecting the DNA-binding paired domain of PAX6 are usually associated with non-aniridia phenotypes like microphthalmia, coloboma or isolated foveal hypoplasia. In this study, we report two missense heterozygous variants in the paired domain of PAX6 resulting in isolated foveal hypoplasia with nystagmus in two independent families: c.112 C > G; p.(Arg38Gly) and c.214 G > C; p.(Gly72Arg) in exons 5 and 6, respectively. Furthermore, we provide evidence that paternal postzygotic mosaicism is the cause of inheritance, with clinically unaffected fathers and reduced affected allele fraction. This work contributes to increase the phenotypic spectrum caused by PAX6 variants, and to our knowledge, is the first report to describe the presence of postzygotic parental mosaicism causing isolated foveal hypoplasia with nystagmus. These results support the growing evidence that suggest an overestimation of sporadic cases with PAX6 variants, which has strong implications for both genetic counselling and family planning.

Somatic Testing and Germline Genetic Status: Implications for Cancer Treatment Decisions and Genetic Counseling

We review recent precision oncology literature pertaining to the implications of germline and somatic genetic information in cancer treatment. The goal of this work is to provide a practical resource for oncology practitioners and genetic providers and discuss practice considerations for those on the frontline of precision oncology. Understanding germline and somatic tumor alterations, patients can be matched to targeted therapy options attacking the specific genetic makeup of that tumor. This information informs treatment decisions about which therapies the cancer is likely to respond to and which treatment options should be avoided. Timely access to germline and somatic genetic testing is critical to ensure that patients have this information for treatment planning, both at diagnosis and through later lines of therapy. The hope of precision oncology is here although significant challenges remain for implementation for routine cancer care.

Empiric Recurrence Risk Estimates for Chronic Tic Disorders: Implications for Genetic Counseling.

Background: Tourette disorder (TD) and other chronic tic disorders are neurodevelopmental/neuropsychiatric disorders characterized by motor and/or vocal tics. Family studies indicate that TD strongly aggregates within families and that other chronic tic disorders are biologically related such that studies typically combine them into any chronic tic disorder (CTD). Because of stigma, bullying, and comorbidity with other neuropsychiatric disorders, CTDs can severely impact the quality of life of individuals with these disorders.Objectives: The genetic architecture of CTDs is complex and heterogeneous, involving a myriad of genetic variants. Thus, providing familial recurrence risks is based on empirical recurrence risk estimates rather than genetic testing. Because empiric recurrence risks for CTDs have not been published, the purpose of this study is to calculate and report these recurrence risks estimates.Methods: Based on population prevalence and increased risk to different relatives from a large population-based family study, we calculated the empiric recurrent risk estimate for each relative type (full sibling, parents, offspring, all first-degree, and all second-degree).Results: The recurrence risk estimate for CTDs in first-degree relatives is 29.9% [95% confidence interval (CI) = 23.2–38.5%]. The risk is higher in males, 33.7% (95% CI = 26.2–43.3%), than females, 24.3% (95% CI = 18.9–31.3%).Conclusions: Given the complex, heterogeneous genetic architecture of CTDs, individuals concerned about recurrence risk should be referred to genetic counseling. Such counseling should include discussion of the derivation and limitations of these empiric recurrence risk estimates, including the upper and lower limits of the range of risk.

Molecular tumor testing in patients with Lynch-like syndrome reveals a de novo mosaic variant of a mismatch repair gene transmitted to offspring

In Lynch-like syndrome, patients have tumors with microsatellite instability but no germline pathogenic variant in mismatch repair genes or somatic methylation of the MLH1 promoter. Identification of the mechanism that causes these tumors is crucial for guiding screening of the patients and their relatives. Double somatic hits are the usual explanation for these cases; however, we have previously reported a de novo mosaic pathogenic variant in a patient with Lynch-like syndrome. Using tumoral NGS analysis of a series of 16 patients with Lynch-like syndrome, we found six patients with double somatic hits, including one patient with mosaicism of a de novo pathogenic variant in MSH2. This variant was transmitted to the patient's offspring, which has significant implications for genetic counseling.

Update on multi-gene panel testing and communication of genetic test results.

With technological advances, multi-gene panel testing has become increasingly used to identify patients at risk for hereditary breast cancer (HBC). There are currently evidence-based interventions and breast cancer screening strategies that exist for cancer prevention and early detection among patients with HBC. Moreover, in addition to the personal impact of identifying HBC, this information may be shared with at-risk family members to amplify the benefits of testing and subsequent care among those at high risk. Opportunities and challenges with the utilization of updated multi-gene panel testing for HBC, including: (a) tumor sequencing with germline consequences; (b) genetic counseling implications; and (c) strategies to improve the communication of genetic test results to family members will be reviewed. With the advances and expansion of genetic testing, all health care providers need to be updated on both the importance and complexities of HBC counseling and testing, in order to optimize patient care.

XAF1 as a modifier of p53 function and cancer susceptibility

Cancer risk is highly variable in carriers of the common TP53-R337H founder allele, possibly due to the influence of modifier genes. Whole-genome sequencing identified a variant in the tumor suppressor XAF1 (E134*/Glu134Ter/rs146752602) in a subset of R337H carriers. Haplotype-defining variants were verified in 203 patients with cancer, 582 relatives, and 42,438 newborns. The compound mutant haplotype was enriched in patients with cancer, conferring risk for sarcoma (P = 0.003) and subsequent malignancies (P = 0.006). Functional analyses demonstrated that wild-type XAF1 enhances transactivation of wild-type and hypomorphic TP53 variants, whereas XAF1-E134* is markedly attenuated in this activity. We propose that cosegregation of XAF1-E134* and TP53-R337H mutations leads to a more aggressive cancer phenotype than TP53-R337H alone, with implications for genetic counseling and clinical management of hypomorphic TP53 mutant carriers.

Synonymous GATA2 mutations result in selective loss of mutated RNA and are common in patients with GATA2 deficiency

Deficiency of the transcription factor GATA2 is a highly penetrant genetic disorder predisposing to myelodysplastic syndromes (MDS) and immunodeficiency. It has been recognized as the most common cause underlying primary MDS in children. Triggered by the discovery of a recurrent synonymous GATA2 variant, we systematically investigated 911 patients with phenotype of pediatric MDS or cellular deficiencies for the presence of synonymous alterations in GATA2. In total, we identified nine individuals with five heterozygous synonymous mutations: c.351C>G, p.T117T (N = 4); c.649C>T, p.L217L; c.981G>A, p.G327G; c.1023C>T, p.A341A; and c.1416G>A, p.P472P (N = 2). They accounted for 8.2% (9/110) of cases with GATA2 deficiency in our cohort and resulted in selective loss of mutant RNA. While for the hotspot mutation (c.351C>G) a splicing error leading to RNA and protein reduction was identified, severe, likely late stage RNA loss without splicing disruption was found for other mutations. Finally, the synonymous mutations did not alter protein function or stability. In summary, synonymous GATA2 substitutions are a new common cause of GATA2 deficiency. These findings have broad implications for genetic counseling and pathogenic variant discovery in Mendelian disorders.

Identification of four novel mutations in the

Alport syndrome (AS) is an inherited progressive nephropathy caused by mutations in one or two of the type IV collagen novel chains (α3, α4 and α5), which are encoded by COL4A3, COL4A4 and COL4A5, respectively. To date, three genetic forms of AS have been reported, including X-linked AS, autosomal recessive AS, and autosomal dominant AS, and ~80% of patients have X-linked AS caused by mutations in COL4A5. In the present study, four novel and one previously reported COL4A5 mutations were identified using targeted next-generation sequencing in Chinese patients suspected of having AS. The results were confirmed by Sanger sequencing, which revealed two novel missense mutations resulting in the substitution of various glycine residues in a collagenous domain containing Gly-X-Y triplet sequence repeats [c.4198G>C, p.(Gly1400Arg) and c.3428G>T, p.(Gly1143Val)], a previously reported missense mutation [c.3071G>A, p.(Gly1024Glu)], a splice site mutation (c.2146+2T>A) and one frameshift mutation [c.1810delC (p.Thr605Ilefs*13)]. After analyzing the affected family members, it was shown that the identified mutations were associated with severe clinical phenotypes. These results broaden the known spectrum of mutations of the COL4A5 gene associated with AS and may have implications for genetic diagnosis, therapy and genetic counseling of affected families.

Whole exome sequencing identified a new compound heterozygous PRKN mutation in a Chinese family with early-onset Parkinson's disease.

Early-onset Parkinson’s disease (EOPD) is usually caused by genetic variants and patients with EOPD develop symptoms before the age of 50, accounting for 5% Parkinson’s disease (PD). Here we present a Chinese Han pedigree with clinical features of EOPD. To determine the diagnosis and pathogenic mutations of this pedigree, whole exome sequencing, Sanger sequencing and real-time quantitative PCR were performed to detect all the four family members. Our results showed that a new form of compound heterozygous mutation in the PRKN gene, consisting of heterozygous point mutation c.850G > C (p.G284R) along with exon 4 deletion, is the causative genetic factor for EOPD in this pedigree. These discoveries may have implications for genetic counseling, clinical management and developing PRKN target gene therapy strategy.

LARS2-Perrault syndrome: a new case report and literature review

BackgroundPerrault syndrome is a rare recessive and genetically heterogeneous disorder characterized by sensorineural hearing loss in males and females and gonadal dysgenesis in females. Mutations in seven different genes have been identified: HARS2, HSD17B4, CLLP, C10orf, ERAL1, TWNK and LARS2.To date, 19 variants have been reported in 18 individuals with LARS2-Perrault syndrome.Case presentationHere we describe the case of an 8-year-old girl with compound heterozygous missense mutations in the LARS2 gene. We identified two missense mutations [c.457A > C, p.(Asn153His) and c.1565C > A, p.(Thr522Asn)] and subsequent familial segregation showed that each parent had transmitted a mutation.ConclusionsThese results have implications for genetic counseling and provide insight into the functional role of LARS2. This case highlights the importance of an early diagnosis. Systematic genetic screening of children with hearing loss allows the early identification of a Perrault syndrome in order to ensure specific endocrinological surveillance and management to prevent secondary complications. Clinical data are compared with the other cases reported in the literature.

Movement Disorders in Genetic Pediatric Ataxias.

Genetic pediatric ataxias are heterogeneous rare disorders, mainly inherited as autosomal-recessive traits. Most forms are progressive and lack effective treatment, with relevant socioeconomical impact. Albeit ataxia represents the main clinical feature, the phenotype can be more complex, with additional neurological and nonneurological signs being described in several forms. In this review, we provide an overview of the occurrence and spectrum of movement disorders in the most relevant forms of childhood-onset genetic ataxias. All types of hypokinetic and hyperkinetic movement disorders of variable severity have been reported. Movement disorders occasionally represent the symptom of onset, predating ataxia even of a few years and therefore challenging an early diagnosis. Their pathogenesis still remains poorly defined, as it is not yet clear whether movement disorders may directly relate to the cerebellar pathology or result from an extracerebellar dysfunction, including the basal ganglia. Recognition of the complete movement disorder phenotype in genetic pediatric ataxias has important implications for diagnosis, management, and genetic counseling.

PD12-09 INHERITED CANCER PREDISPOSITION GENE VARIANTS IN PATIENTS WITH NON-MUSCLE INVASIVE BLADDER CANCER

INTRODUCTION AND OBJECTIVE: Emerging data have shown that patients with locally advanced and metastatic urothelial cancer frequently harbor rare germline variants in cancer predisposition genes, particularly in DNA damage response (DDR) genes. The prevalence of such rare germline variants in patients with non-muscle invasive bladder cancer (NMIBC), the most common form of urothelial cancer, has not been thoroughly studied. METHODS: Patients with NMIBC who were unselected for inherited cancer syndromes were prospectively enrolled in a protocol for molecular profiling of tumor-normal DNA pairs using next-generation sequencing within a CLIA-certified lab (NCT01775072). Germline variation analysis was performed on a clinically annotated cohort of 100 patients with NMIBC that we had previously reported on their somatic mutational spectrum (Pietzak et al Eur Urol 2017). Pathogenic or likely pathogenic (P/LP) germline variants in a panel of 82 genes associated with hereditary cancer predisposition were assessed in accordance with recommendations of the American College of Medical Genetics and Genomics. RESULTS: We identified P/LP germline variants in 12 (15.7%) patients with high-grade NMIBC (n = 76) and 0 patients with low-grade NMIBC (n = 24). Nine (11.8%) patients with high-grade NMIBC had P/LP variants in DDR genes; four were in nucleotide excision repair genes (ERCC2 [2] and ERCC3 [2]) and four were in homologous recombination repair genes (BRCA1 [1], BARD1 [1], RAD50 [1], and RECQL4 [1]). An additional patient had a P/LP germline mutation SDHA and two others had P/LP low-penetrance germline mutations in FH and APC. Interestingly, no patient with a germline mutation had early-onset disease (≤ 45 years at diagnosis) or a family history of urothelial cancer. Compared to patients with high-grade NMIBC without germline variants, those with P/LP germline variants had a higher frequency of nonurothelial cancers (15% vs 42%), Ashkenazi Jewish ancestry (27% vs 42%), and multifocal tumors at initial diagnosis (42% vs 75%). Correlation of P/LP variants with clinical outcomes in a larger cohort is ongoing and is expected to be available for presentation at the meeting. CONCLUSIONS: Our findings suggest that genetic predisposition may play a larger role than expected in NMIBC, as P/LP germline variants were seen in 16% of patients with high-grade NMIBC. If validated, these results may have profound implications for genetic counseling, screening, and prevention. The prevalence of germline DDR variants, which may increase susceptibility to bladder cancer, suggests that therapeutic strategies exploiting tumor vulnerabilities due to impaired DNA repair warrant further investigation in high-grade NMIBC. Source of Funding: This work was supported by the Sidney Kimmel Center for Prostate and Urologic Cancers, the Michael and Zena Wiener for Therapeutics Program in Bladder Cancer, Pin Down Bladder Cancer, Cycle for Survival, the Marie-Josee and Henry R. Kravis Center for Molecular Oncology, NIH/NCATS Grant Number UL1-TR002384, the National Cancer Institute Cancer Center Core Grant Number P30-CA008748, MSKCC SPORE in Bladder Cancer P50-CA221745, NIH/NCI K12 Paul Calabresi Career Development Award for Clinical Oncology (K12 CA184746)