Quantitative assessment of craniofacial morphology in Johanson-Blizzard syndrome.

BACKGROUND: Here we apply objective, reliable methods of dysmorphology diagnosis to a patient with Johanson-Blizzard syndrome (MIM #243800). Using an extensive normative database, we computed standardized scores on a graded continuum for operational definitions of nasal alar hypoplasia, a commonly observed feature of this condition. CASE: Most of these measurements in this case were greater than 2 standard deviations below the mean, adjusted for age, gender, and ethnicity. CONCLUSION: This report provides a worked example of quantitative anthropometric assessment in the context of a case report, using tools that may find general application in clinical genetics.