Establishing a nephrology genetic clinic Pinto e Vairo, Filippo; Kemppainen, Jennifer L.; Lieske, John C. ...
Kidney international,
08/2021, Letnik:
100, Številka:
2
Journal Article
Though next-generation sequencing (NGS) tests like exome sequencing (ES), genome sequencing (GS), and panels derived from exome and genome data (EGBP) are effective for rare diseases, the ideal ...diagnostic approach is debated. Limited research has explored reanalyzing raw ES and GS data post-negative EGBP results for diagnostics.
We analyzed complete ES/GS raw sequencing data from Mayo Clinic's Program for Rare and Undiagnosed Diseases (PRaUD) patients to assess whether supplementary findings could augment diagnostic yield. ES data from 80 patients (59 adults) and GS data from 20 patients (10 adults), averaging 43 years in age, were analyzed. Most patients had renal (n=44) and auto-inflammatory (n=29) phenotypes. Ninety-six cases had negative findings and in four cases additional genetic variants were found, including a variant related to a recently described disease (RRAGD-related hypomagnesemia), a variant missed due to discordant inheritance pattern (COL4A3), a variant with high allelic frequency (NPHS2) in the general population, and a variant associated with an initially untargeted phenotype (HNF1A).
ES and GS show diagnostic yields comparable to EGBP for single-system diseases. However, EGBP's limitations in detecting new disease-associated genes underscore the necessity for periodic updates.
To describe the experience and outcome of performing whole-exome sequencing (WES) for resolution of patients on a diagnostic odyssey in the first 18 months of an individualized medicine clinic (IMC).
...The IMC offered WES to physicians of Mayo Clinic practice for patients with suspected genetic disease. DNA specimens of the proband and relatives were submitted to WES laboratories. We developed the Genomic Odyssey Board with multidisciplinary expertise to determine the appropriateness for IMC services, review WES reports, and make the final decision about whether the exome findings explain the disease. This study took place from September 30, 2012, to March 30, 2014.
In the first 18 consecutive months, the IMC received 82 consultation requests for patients on a diagnostic odyssey. The Genomic Odyssey Board deferred 7 cases and approved 75 cases to proceed with WES. Seventy-one patients met with an IMC genomic counselor. Fifty-one patients submitted specimens for WES testing, and the results have been received for all. There were 15 cases in which a diagnosis was made on the basis of WES findings; thus, the positive diagnostic yield of this practice was 29%. The mean cost per patient for this service was approximately $8000. Medicaid supported 27% of the patients, and 38% of patients received complete or partial insurance coverage.
The significant diagnostic yield, moderate cost, and notable health marketplace acceptance for WES compared with conventional genetic testing make the former method a rational diagnostic approach for patients on a diagnostic odyssey.
To increase genetic counseling referrals for patients with newly diagnosed epithelial ovarian cancer (EOC).
A practice-gap analysis was performed after measuring baseline genetic counseling referral ...rates to identify barriers to referral from the multidisciplinary single institution EOC care group. A Genetics Referral Toolkit consisting of a referral template, a genetic risk checklist, family history worksheet and provider and patient awareness was developed to address identified gaps with the goal of increasing referral rates. Clinical characteristics, referral placement, completion of genetic counseling/testing were abstracted for a historic cohort and intervention cohort. Data for the two cohorts were compared using chi-square, Fisher's exact test, or t-test. Association with referral was determined by univariate logistic regression.
Eighty one patients from July through December 2013 (historic cohort) and 62 patients from July through December 2015 (intervention cohort) were identified as having a new diagnosis of EOC. Among these women, genetic counseling referral rates increased from 48.1% (39/81) in 2013 to 74.2% (46/62) in 2015 (p=0.002) after implementation of the toolkit. In a subset of patients without a previous genetic counseling referral, 87.9% (29/33) completed counseling and 79.3% (23/29) pursued testing from the historic cohort. In the intervention cohort, 60% (24/40) were seen for counseling and 100% (24/24) had testing.
Application of a quality improvement process to create a Genetics Referral Toolkit increased the genetic counseling referral rate in patients with a new diagnosis of EOC. The majority of patients who were referred completed genetics consultation and elected genetic testing.
•Implementation of bundled interventions improved genetics referral in EOC patients.•Genetics referrals from oncology providers yield a high rate of consult completion.•There is a high rate of completing genetic testing after genetic counseling.
This abstract is based on unpublished data
. OBJECTIVES/GOALS: The estimates of unbiased first-degree relatives (FDRs) risk of cancers would enhance genetic counseling of at-risk FDRs in families ...where the pancreatic cancer (PC) proband carrying a germline variant. This study aims at quantifying gene-specific risks of six cancers among FDRs of PC patients with germline variants in cancer-associated genes. METHODS/STUDY POPULATION: In the prospective, clinic-based Mayo Clinic Biospecimen Resource for Pancreas Research registry, 4,562 PC patients had previously undergone germline genetic testing for pancreatic cancer-associated genes through either research studies or clinical testing. Of these, 234 PC probands were found to carry germline pathogenic/likely pathogenic variants (PLPV) among 9 genes of interest and had provided detailed demographic and cancer data on their FDRs by questionnaire. We focused on six cancer types (ovary, breast, uterus, pancreas, colon, and malignant melanoma) in FDRs as reported by the probands. Standardized incidence ratios were calculated to estimate risk of six cancers among FDRs of PC patients carrying PLPV by gene. RESULTS/ANTICIPATED RESULTS: 1,670 FDRs (mean age 58.1+17.8SD; 48.9% female) were included in the study. We found significantly increased risk of ovarian cancer in female FDRs of PC probands who carry PLPV in BRCA1 (SIR 9.49, 95%CI:3.06-22.14) or BRCA2 (3.72, 95%CI:1.36-8.11), and breast cancer risks were higher with BRCA2 (2.62, 95%CI:1.89-3.54). Uterine cancer risk was increased in FDRs of PC probands who carry PLPV for Lynch Syndrome mismatch repair (MMR) (6.53, 95%CI:2.81-12.86). PC risk was also increased (ATM 4.53, 95% CI:2.69-7.16; BRCA2 3.45, 95%CI:1.72-6.17; CDKN2A 7.38, 95%CI:3.18-14.54; PALB2 5.39, 95%CI:1.45-13.79). Increased colon cancer risk was observed in FDRs of probands who carried MMR PLPV (5.83, 95%CI:3.70-8.75), while melanoma risk was elevated for FDRs of probands with CDKN2A PLPV (7.47, 95%CI:3.97-12.77). DISCUSSION/SIGNIFICANCE: PLPV in nine syndrome-associated genes in PC probands are associated with increased risk of six cancers in FDRs. The findings underscore the importance of risk estimation of various other cancers in PC families for screening, early detection, intervention, and cascade genetic testing.
Increased cancer risk in first-degree relatives of probands with pancreatic ductal adenocarcinoma (PDAC probands) who carry pathogenic or likely pathogenic germline variants (PGVs) in cancer ...syndrome-associated genes encourages cascade genetic testing. To date, unbiased risk estimates for the development of cancers on a gene-specific basis have not been assessed.
To quantify the risk of development of PDAC and extra-PDAC among first-degree relatives of PDAC probands who carry a PGV in 1 of 9 cancer syndrome-associated genes-ATM, BRCA1, BRCA2, PALB2, MLH1, MSH2, MSH6, PMS2, and CDKN2A.
This case series focused on first-degree relatives of PDAC probands carrying PGVs in specific cancer syndrome-associated genes. The cohort comprised clinic-ascertained patients enrolled in the Mayo Clinic Biospecimen Resource for Pancreas Research registry with germline genetic testing. In total, 234 PDAC probands carrying PGVs were drawn from the prospective research registry of 4562 participants who had undergone genetic testing of cancer syndrome-associated genes. Demographic and cancer-related family histories were obtained by questionnaire. The data were collected from October 1, 2000, to December 31, 2021.
For the PDAC probands, the genetic test results of the presence of PGVs in 9 cancer syndrome-associated genes were obtained by clinical testing. Cancers (ovary, breast, uterus or endometrial, colon, malignant melanoma, and pancreas) among first-degree relatives were reported by the probands. Standardized incidence ratios (SIRs) were used to estimate cancer risks among first-degree relatives of PDAC probands carrying a PGV.
In total, 1670 first-degree relatives (mean SD age, 58.1 17.8 years; 853 male 51.1%) of 234 PDAC probands (mean SD age, 62.5 10.1 years; 124 male 53.0%; 219 94.4% White; 225 98.7% non-Hispanic or non-Latino) were included in the study. There was a significantly increased risk of ovarian cancer in female first-degree relatives of probands who had variants in BRCA1 (SIR, 9.49; 95% CI, 3.06-22.14) and BRCA2 (SIR, 3.72; 95% CI, 1.36-8.11). Breast cancer risks were higher with BRCA2 variants (SIR, 2.62; 95% CI, 1.89-3.54). The risks of uterine or endometrial cancer (SIR, 6.53; 95% CI, 2.81-12.86) and colon cancer (SIR, 5.83; 95% CI, 3.70-8.75) were increased in first-degree relatives of probands who carried Lynch syndrome mismatch repair variants. Risk of PDAC was also increased for variants in ATM (SIR, 4.53; 95% CI, 2.69-7.16), BRCA2 (SIR, 3.45; 95% CI, 1.72-6.17), CDKN2A (SIR, 7.38; 95% CI, 3.18-14.54), and PALB2 (SIR, 5.39; 95% CI, 1.45-13.79). Melanoma risk was elevated for first-degree relatives of probands with CDKN2A variants (SIR, 7.47; 95% CI, 3.97-12.77).
In this case series, the presence of PGVs in 9 cancer syndrome-associated genes in PDAC probands was found to be associated with increased risk of 6 types of cancers in first-degree relatives. These gene-specific PDAC and extra-PDAC cancer risks may provide justification for clinicians to counsel first-degree relatives about the relevance and importance of genetic cascade testing, with the goal of higher uptake of testing.
•Adrenomyeloneuropathy may present with only mild myelopathic features.•Targeted gene approach aids diagnosis in atypical presentations.•Functional assay confirmation is needed to confirm causality ...of genetic variants.
X-linked adrenoleukodystrophy is a peroxisomal disorder caused by a mutation in ABCD1 gene. The three main phenotypes of X-linked adrenoleukodystrophy include cerebral adrenoleukodystrophy, adrenomyeloneuropathy, and isolated primary adrenal insufficiency. More than 750 non-recurrent mutations exist throughout the coding region of the ABCD1 gene. We report a 62-year-old man with a 17-year history of progressive gait imbalance and numb feet. He had noted difficulty rising from a chair for 3 years. Examination revealed proximal lower limb weakness and length-dependent sensory loss with preservation of reflexes and unilateral Babinski sign. Electrodiagnostic evaluation confirmed a length-dependent sensorimotor peripheral neuropathy and proximal myopathy. Family history was remarkable for similar symptoms in 6 siblings. A targeted gene approach for 102 known peripheral neuropathy genes led to discovery of ABCD1 mutation confirmed by kindred evaluation and biochemical assay. This case highlights the importance of combining targeted gene approaches with functional assay confirmation especially for atypical clinical presentations.
Newborn screening is designed for presymptomatic identification of serious conditions with effective early interventions. Clinical laboratories must perform prospective pilot studies to ensure that ...the analytical performance and workflow for a given screening test are appropriate. We assessed the potential to screen newborns for fragile X syndrome, a monogenic neurodevelopmental disorder, by establishing a customized, high-throughput PCR and analysis software system designed to detect fragile X mental retardation 1 gene repeat expansions from dried blood spots (DBSs). Assay precision, accuracy, sensitivity, and specificity were characterized across the categorical range of repeat expansions. The assay consistently resolved genotypes within three CGG repeats of reference values up to at least 137 repeats and within six repeats for larger expansions up to 200 repeats. Accuracy testing results were concordant with reference results. Full and premutation alleles were detected from subnanogram DNA inputs eluted from DBSs and from mixtures with down to 1% relative abundance of the respective expansion. Analysis of 963 deidentified newborn DBS samples identified 957 normal and 6 premutation specimens, consistent with previously published prevalence estimates. These studies demonstrate that the assay system can support high-throughput newborn screening programs.
PDF