Accuracy in identification of patients with 22q11.2 deletion by likely care providers using facial photographs

Numerous facial characteristics are associated with velocardiofacial syndrome. Care providers may use these facial characteristics to identify patients who may benefit from fluorescence in situ hybridization genetic testing to determine the presence of the 22q11.2 deletion. The purpose of this study was to test the hypothesis that experienced care providers were able to correctly diagnose the 22q11.2 deletion on the basis of studying frontal facial photographs. After approval was obtained from the human studies committee, patients who had undergone fluorescence in situ hybridization genetics testing for the presence of a 22q11.2 deletion were asked to submit two frontal photographs: one at infancy and one beyond the second birthday. These photographs were randomized, made anonymous, and then placed on a secure Web site. Specialists in the fields of plastic surgery, otolaryngology, genetics, and speech pathology were asked to evaluate their experience and confidence levels in diagnosing a 22q11.2 deletion and were then asked to rate the photographs by likelihood of deletion using a five-point Likert scale. Thirty-two specialists (10 surgeons, nine geneticists, and 13 speech pathologists) participated in the study. On the basis of clear responses, respondents predicted the presence (sensitivity) and absence (specificity) of the 22q11.2 deletion at chance levels. Of the remaining responses, 20 to 25 percent were unsure and 20 to 25 percent were clearly wrong. When an unsure response was treated as a weak positive, the results favored sensitivity slightly, with a sensitivity of 70 percent and a specificity of 50 percent. Sensitivity improved somewhat with experience, as measured by the number of patients seen per year. The prediction of the presence or absence of the 22q11.2 deletion at chance levels suggests that the ability to diagnose on the basis of appearance alone is not a sufficient diagnostic tool. Although the ability does increase with experience, it is of statistical but not clinical significance.