Reproductive Risk Estimation Calculator for Balanced Translocation Carriers: An Improved Web-based Resource for Medical Genetics Professionals

Abstract

Balanced translocation carriers experience elevated reproductive risks, including pregnancy loss and children with anomalies due to generating chromosomally unbalanced gametes. While understanding the likelihood of producing unbalanced conceptuses is critical for individuals to make reproductive decisions, risk estimates are difficult to obtain as most balanced translocations are unique. To improve reproductive risk estimates, Drs. Trunca and Mendell created models based on a logistic regression analysis of a dataset of over 6000 individuals from over 1000 translocation families. While risk assessments using these models have been offered as a free service for years, this protocol aims to create a sustainable model for genetics professionals to obtain risk estimates for their patients directly. This protocol guides the user through collecting clinical information, using a risk-generating calculator based on the models, and interpreting the calculator outputs. This version of the protocol has been updated from the initial publication to introduce an additional resource to the community that is intended to improve accessibility and reduce error in calculating risks. In addition to the previously offered custom Java program, a web-based calculator that calculates age-adjusted miscarriage risks is now available. A practice tutorial is provided for both versions of the calculator to ensure competency in interpretation prior to use. © 2025 Wiley Periodicals LLC.

Basic Protocol 1: Estimation of reproductive risks for balanced translocation carriers

Basic Protocol 2: Practical examples of typical patient encounters with instructive interpretations