Practice resource-focused revision: Standardized pedigree nomenclature update centered on sex and gender inclusivity: A practice resource of the National Society of Genetic Counselors.

This focused revision builds on the expert opinions from the original publications of 'Recommendations for human standardized pedigree nomenclature' published in 1995 and updated in 2008. Our review of medical publications since 2008 did not identify any fundamental systematic alternative pedigree nomenclature. These findings attest to the relevance of most of the nomenclature with the critical exception of the nomenclature used to denote sex assigned at birth and gender. While we are not recommending the creation of any new pedigree symbols, a major focus of this publication is clarification of the use of symbols and language in the description of the distinction between sex and gender, with a view to ensuring safe and inclusive practice for people who are gender-diverse or transgender. In addition, we recommend modifications to the way that carrier status is depicted. Our goal is to respect individual differences and identities while maintaining biologically, clinically, and genetically meaningful information.

Impact of Cell-Free Fetal DNA Screening on Patients' Choice of Invasive Procedures after a Positive California Prenatal Screen Result.

Until recently, maternal serum analyte levels paired with sonographic fetal nuchal translucency measurement was the most accurate prenatal screen available for Trisomies 18 and 21, (91% and 94% detection and false positive rates of 0.31% and 4.5% respectively). Women with positive California Prenatal Screening Program (CPSP) results have the option of diagnostic testing to determine definitively if the fetus has a chromosomal abnormality. Cell-free fetal (cff-) DNA screening for Trisomies 13, 18, and 21 was first offered in 2012, allowing women with positive screens to choose additional screening before diagnostic testing. Cff-DNA sensitivity rates are as high as 99.9% and 99.1%, with false positive rates of 0.4% and 0.1%, for Trisomies 18 and 21, respectively. A retrospective chart review was performed in 2012 on 500 CPSP referrals at the University of California, San Diego Thornton Hospital. Data were collected prior to and after the introduction of cff-DNA. There was a significant increase in the number of participants who chose to pursue additional testing and a decrease in the number of invasive procedures performed after cff-DNA screening was available. We conclude that as fetal aneuploidy screening improves, the number of invasive procedures will continue to decrease.

Standardized human pedigree nomenclature: update and assessment of the recommendations of the National Society of Genetic Counselors.

In 1995, the Pedigree Standardization Task Force (PSTF) of the National Society of Genetic Counselors (NSGC) proposed a system of pedigree nomenclature. Recently, the PSTF (now called the Pedigree Standardization Work Group or PSWG) sought evidence that the published symbols met the needs of health professionals, were incorporated into health professional training and were utilized in publications. We searched PubMed and reference lists of select publications, reviewed the Instructions for Authors of several journals, searched the websites of professional societies, sought comment from the membership of the NSGC, and looked at recommendations and training practices of various health professional organizations. Many journals still do not cite specific standards for pedigrees, but those found cited the PSTF nomenclature. We did not find significant objections or alternatives to the 1995 nomenclature. Based on our review, we propose only a few minor stylistic changes to the pedigree symbols. The pedigree nomenclature of the NSGC is the only consistently acknowledged standard for drawing a family health history. We recommend regular and continued review of these pedigree standards to determine if additional symbols are needed to accommodate changes in clinical practice to ensure that the symbols continue to meet the needs of health professionals and researchers as well as adhere to evolving ethical and privacy standards. All health professionals, trainees, and researchers should be made aware of the utility of using a common pedigree nomenclature in clinical practice and publication. This will become particularly important as electronic medical records become more widely utilized.