This document summarizes a study that aims to determine which combinations of clinical signs observed on prenatal ultrasounds best predict a mutation in genes COL1A1 or COL1A2 that causes Osteogenesis imperfecta (OI), a genetic disorder that causes brittle bones. The study analyzes data collected from prenatal cases submitted to a collagen diagnostic lab, including ultrasound findings of signs like shortened long bones, bowed bones, and fractures, as well as the results of genetic testing. The goal is to establish guidelines for physicians to help recognize OI in fetuses and determine when genetic testing is required, in order to provide better care for affected fetuses and families.

1. Does ultrasound identification of in-utero fractures predict Osteogensis
imperfecta?
Maryam Rahmani1,2
, Melanie Pepin2
, Dr. Peter H. Byers2
1
University of Washington GenOM Project, 2
University of Washington Department of Pathology
Osteogenesis imperfecta (OI) is an inherited brittle bone disorder that varies in clinical severity
from mild to lethal forms. The mutation generally occurs in type one collagen genes (COL1A1
and COL1A2), and it can be confirmed by molecular testing. The goal of this project is to
discover which combinations of clinical signs of Osteogenesis imperfecta are most likely to yield
positive results for a mutation in COL1A1 or COL1A2, and to develop guidelines which could
be used by physicians when diagnosing OI with in-utero fetuses. The data for this study was
collected from in-utero cases submitted to the University of Washington Collagen Diagnostic
Lab from around the world. In this study, I tabulated the multiple signs of OI from patient data
organized by the signs shown on ultrasounds previous to genetic testing (ex: shortened long
bones, bowed bones, multiple fractures, etc.), and the results of genetic testing. With this
information, it will be easier for doctors and genetic counselors to recognize cases of OI in
fetuses and determine when the appropriate genetic testing is required. The findings in this study
will make it easier for care to be administered to the fetuses and family members dealing with
Osteogenesis imperfecta.