The Development of an Infrastructure to Facilitate the Use of Whole Genome Sequencing for Population Health

The clinical use of genomic analysis has expanded rapidly resulting in an increased availability and utility of genomic information in clinical care. We have developed an infrastructure utilizing informatics tools and clinical processes to facilitate the use of whole genome sequencing data for population health management across the healthcare system. Our resulting framework scaled well to multiple clinical domains in both pediatric and adult care, although there were domain specific challenges that arose. Our infrastructure was complementary to existing clinical processes and well-received by care providers and patients. Informatics solutions were critical to the successful deployment and scaling of this program. Implementation of genomics at the scale of population health utilizes complicated technologies and processes that for many health systems are not supported by current information systems or in existing clinical workflows. To scale such a system requires a substantial clinical framework backed by informatics tools to facilitate the flow and management of data. Our work represents an early model that has been successful in scaling to 29 different genes with associated genetic conditions in four clinical domains. Work is ongoing to optimize informatics tools; and to identify best practices for translation to smaller healthcare systems.

Population prevalence of individuals meeting criteria for hereditary breast and ovarian cancer testing

Background

Personal cancer diagnosis and family cancer history factor into which individuals should undergo genetic testing for hereditary breast and ovarian cancer (HBOC) syndrome. Family history is often determined in the research setting through kindreds with disease clusters, or clinically from self‐report. The population prevalence of individuals with diagnostic characteristics and/or family cancer history meeting criteria for HBOC testing is unknown.

Methods

Utilizing Surveillance, Epidemiology, and End Results (SEER) cancer registry data and a research resource linking registry records to genealogies, the Utah Population Database, the population‐based prevalence of diagnostic and family history characteristics meeting National Comprehensive Cancer Network (NCCN) criteria for HBOC testing was objectively assessed.

Results

Among Utah residents with an incident breast cancer diagnosis 2010‐2015 and evaluable for family history, 21.6% met criteria for testing based on diagnostic characteristics, but the proportion increased to 62.9% when family history was evaluated. The proportion of cases meeting testing criteria at diagnosis was 94% for ovarian cancer, 23% for prostate cancer, and 51.1% for pancreatic cancer. Among an unaffected Utah population of approximately 1.7 million evaluable for family history, 197,601 or 11.6% met testing criteria based on family history.

Conclusions

This study quantifies the population‐based prevalence of HBOC criteria using objectively determined genealogy and cancer incidence data. Sporadic breast cancer likely represents a portion of the high prevalence of family cancer history seen in this study. These results underline the importance of establishing presence of a deleterious mutation in an affected family member, per NCCN guidelines, before testing unaffected relatives.

The impact of utilization of early aneuploidy screening on amniocenteses available for training in obstetrics and fetal medicine

OBJECTIVE

First-trimester aneuploidy screening has high detection rates and low false-positive rates. Their use as well as the implementation of non-invasive prenatal testing may affect specialty training in prenatal diagnosis procedures.

STUDY DESIGN

Descriptive study of first-trimester aneuploidy screening and amniocentesis in an obstetric training program. Screening methods were tracked from their introduction in 2004 through 2011. The volume of amniocentesis procedures from 2000 to 2011 was evaluated.

RESULTS

First-trimester screening tests increased from 283 to 1225 between 2005 and 2011, whereas genetic amniocenteses declined from 460 to 168 during the same period. The percent of older women who chose a first-trimester screen test rose from 12.7% to 44.2%

CONCLUSION

First-trimester screening options reduce genetic amniocenteses available for training. Fetal medicine and general obstetrics training programs need to evaluate their clinical experience and determine whether simulation training methods are needed for education.

141. DEVELOPMENT OF A MODEL SYSTEM TO ASSESS THE REGULATION OF LEYDIG STEM CELL DIFFERENTIATION

The Leydig cells of the testis are responsible for the production of ca. 95% of all circulating androgens in the adult male. There is substantial evidence now that loss of Leydig cell (LC) functionality may account in part for declining androgen levels in the ageing male. Some of this loss of functionality appears to be due to disruption of early LC differentiation processes caused by exposure to environmental endocrine disrupting substances. We have made use of the ability of the alkylating agent ethane dimethane sulfonate (EDS) to destroy specifically all immature and adult LC to develop a model system which allows us to quantitatively assess the differentiation of a new population of LC from resident stem cells in the testis. Following a single bolus injection of EDS into adult Sprague Dawley rats, unless additional testosterone is present to suppress the HPG axis, new LC redifferentiate from the resident stem cells in the testis. These are small spindle-shaped mesenchymal cells which are located in the peritubular region adjacent to the seminiferous tubules. In the absence of mature LC these mesenchymal cells differentiate first into LC progenitor cells, then immature LC, and finally into adult LC, following a precisely defined kinetic which can be mapped using quantitative RT-PCR for LC specific genes in whole testis samples. We are using this model to examine the effect of in vivo application of known environmental endocrine disrupting agents on LC differentiation, and hence their potential to cause long-term loss of LC functionality.

280. INSL3 is a measure of human Leydig cell functionality both during fetal and adult life

Insulin like factor 3 (INSL3) and testosterone are the two major secretory products of the testis, both produced by the interstitial Leydig cells. The Leydig cells of the testis have two distinct generations, one developing before birth (fetal Leydig cells, FLC) and an adult type (adult Leydig cells, ALC) that become differentiated and functional at puberty. Although these two types of Leydig cells represent distinct populations, rodent studies show that both types produce testosterone and INSL3. Both are presumed to have evolved from a common stem cell pool. We measured INSL3 levels in human amniotic fluids collected at various times of gestation and show for the first time that the human male fetus indeed generates INSL3 at a time appropriate for the first transabdominal phase of testicular descent, which appears to be the primary physiological role for the fetal hormone. INSL3 appears to be independent of androgen production. The adult type Leydig cells (in adult men) secrete INSL3 that can be measured in the peripheral circulation at levels ranging from 0.5 to 2.5 ng/mL. We studied a large randomly recruited cohort of 1183 men from South Australia, comparing serum INSL3 concentrations with age, and a variety of endocrine, cognitive and morphological parameters. INSL3 concentration was observed to decline significantly with age. This however, had no correlation with testosterone or components of the HPG axis. INSL3 is an independent measure of Leydig cell function (quality and number), which appears to be independent of acute control via the HPG axis. Its decline with age reflects a decline in the properties of the Leydig cell population only, and emphasises a gonadal component in the age-related decrease in androgen production. Research supported by ARC Discovery grant DP0773315.