A Polygenic Score for Type 2 Diabetes Improves Risk Stratification Beyond Current Clinical Screening Factors in an Ancestrally Diverse Sample.

A substantial proportion of the adult United States population with type 2 diabetes (T2D) are undiagnosed, calling into question the comprehensiveness of current screening practices, which primarily rely on age, family history, and body mass index (BMI). We hypothesized that a polygenic score (PGS) may serve as a complementary tool to identify high-risk individuals. The T2D polygenic score maintained predictive utility after adjusting for family history and combining genetics with family history led to even more improved disease risk prediction. We observed that the PGS was meaningfully related to age of onset with implications for screening practices: there was a linear and statistically significant relationship between the PGS and T2D onset (-1.3 years per standard deviation of the PGS). Evaluation of U.S. Preventive Task Force and a simplified version of American Diabetes Association screening guidelines showed that addition of a screening criterion for those above the 90th percentile of the PGS provided a small increase the sensitivity of the screening algorithm. Among T2D-negative individuals, the T2D PGS was associated with prediabetes, where each standard deviation increase of the PGS was associated with a 23% increase in the odds of prediabetes diagnosis. Additionally, each standard deviation increase in the PGS corresponded to a 43% increase in the odds of incident T2D at one-year follow-up. Using complications and forms of clinical intervention (i.e., lifestyle modification, metformin treatment, or insulin treatment) as proxies for advanced illness we also found statistically significant associations between the T2D PGS and insulin treatment and diabetic neuropathy. Importantly, we were able to replicate many findings in a Hispanic/Latino cohort from our database, highlighting the value of the T2D PGS as a clinical tool for individuals with ancestry other than European. In this group, the T2D PGS provided additional disease risk information beyond that offered by traditional screening methodologies. The T2D PGS also had predictive value for the age of onset and for prediabetes among T2D-negative Hispanic/Latino participants. These findings strengthen the notion that a T2D PGS could play a role in the clinical setting across multiple ancestries, potentially improving T2D screening practices, risk stratification, and disease management.

Genetic Counselors' Perspectives and Practices Regarding Expanded Carrier Screening after Initial Clinical Availability.

Expanded carrier screening (ECS), introduced in 2009, identifies carriers for dozens or hundreds of recessive diseases. At the time of its introduction into clinical use, perspectives of the genetic counseling community regarding ECS were unknown. We conducted a survey in early 2012 of GCs and report the results here. They represent a snapshot of opinions and usage at that time, providing a baseline for comparison as the technology continues to evolve and as usage increases. The survey assessed personal perspectives, opinions on clinical implementation and clinical utilization of ECS. The sample included 337 GCs of varying clinical fields, of whom 150 reported practicing in reproductive settings. Our findings demonstrate that, at the time, GCs indicated general agreement with ECS as a concept - for example, most GCs agreed that carrier screening should address diseases outside of current guidelines and also indicated personal interest in electing ECS. There were also disagreements or concerns expressed regarding appropriate pre- and post-test counseling (e.g., the content and delivery mode of adequate informed consent) and practical implementation (e.g., the amount of time available for follow-up care). This was the first quantitative study of a large number of GCs and it revealed initial overall support for ECS among the GC profession. The authors plan to re-administer a similar survey, which may reveal changes in opinions and/or utilization over time. A follow up survey would also allow further exploration of questions uncovered by these data.

Orthopedic manifestations and implications for individuals with Costello syndrome.

Costello syndrome is a rare genetic condition caused by heterozygous alterations in HRAS and characterized by multi-system abnormalities. Individuals with Costello syndrome usually present with severe feeding difficulties in infancy, short stature, coarse facial features, increased tumor risks, cardiac and neurological complications, intellectual disability and orthopedic complications. This study further defines the orthopedic manifestations affecting individuals with Costello syndrome. We studied 43 participants and performed medical records review, clinical examinations and orthopedic inquiry forms. In 23 participants, hip and or spinal imaging assessments were completed. Serial radiographs were analyzed when available. A total of 25 orthopedic manifestations were identified. Ten manifestations were seen in the majority of the participants: hypotonia (87%), ligamentous laxity (85%), scoliosis (63%), kyphosis (58%), characteristic hand deformities (85%), ulnar deviation of the wrist (63%), elbow (55%) and shoulder contractures (65%), tight Achilles tendon (73%), and pes planus (53%). Other characteristics of special note were hip dysplasia (45%), foot deformities requiring surgical intervention (38%) and osteopenia/osteoporosis (47%). We also studied the development of the hips and spine. Uni- or bilateral hip dysplasia was congenital in some, while it developed throughout childhood in others. Spinal involvement included scoliosis, kyphosis, lordosis, and curvature reversal (thoracic lordosis and lumbar kyphosis). Based on these findings, we recommend routine referral to an orthopedic surgeon as well as instituting screening protocols for hips and spine for individuals with Costello syndrome.