Type: Poster

Event: 2005 Annual Clinical Genetics Meeting

Date: March 18, 2005

Location: Grapevine (Dallas), Texas

Authors: Amy E. Roberts, Christine T. Finn, Taryn A. Schiripo, Raju S. Kucherlapati, and Curtis K. Deutsch

Abstract: Objective: Although facial dysmorphology is a very common feature of many disorders, no clear-cut criteria for defining this characteristic dysmorphology are available in many cases. Instead, the facial features have been grouped under categories such as dysmorphic features, and clinicians rely on a visual gestalt assessment as well as quantitative morphometric assessments. These manual measurements require time and an expert to obtain them. Facial feature assessment is an essential component of the clinical diagnosis of both Noonan syndrome (NS) and Velocardiofacial syndrome (VCFS), especially in patients who lack major clinical manifestations. We have developed a new approach to systematically and quantitatively obtain morphometric measurements that would help better define the dysmorphology in patients with NS and VCFS. Methods: We used three-dimensional photogrammetric methods to assess dysmorphology seen among patients with a clinical diagnosis of NS or VCFS and relate these findings to other phenotypic features and genotype status. The apparatus (from Atlanta-based 3dMD) we use generates a 3D point cloud for analysis of facial images and a software analytic system enables specific measurements. The three dimensional image data correlate with manual measurements and the results are virtually interchangeable. The measurements are resolute, valid, and reliable. Patients were measured for broad nasal root, hypoplastic nasal alae, narrow palpebral fissure, downward palpebral slant, hypertelorism, malar flatness, narrow mouth, elongated face, decreased calvarial size, small auricles (width and length), retrusive mandible, and short stature. Patients with NS were measured for broad forehead, broad nasal root, hypertelorism, downward palpebral slant, malar flatness, retrusive mandible, low set ears, and posteriorly rotated ears. Each NS patient had PTPN11 gene sequencing and each VCFS patient had 22q11 deletion testing completed.

( back )