Abnormal oral mucosal light reflectance in achondroplasia.

No markers for the unaffected parents of children with achondroplasia (ACH) are known to date. Here, the value of oral mucosal reflectance in identifying unaffected parents of ACH patients with sporadic mutations was assessed. The study involved ACH children (n = 30), unaffected ACH parents (n = 60), and a sex- and age-matched controls (control children, n = 30; control parents, n = 60). Light reflectance of the lower gingival and vestibular oral mucosa was measured using an imaging reflectance system in the optical spectrum (400-700 nm wavelengths). Significantly higher reflectance values in the 410 to 630 nm wavelength range were observed in ACH patients (P < or = .0063), whereas significantly lower reflectance values over the whole optical spectrum were observed in ACH parents (P < or = .0001). A reflectance cutoff value < or =4.71\% at the 430 nm wavelength identified ACH parents with 100\% sensitivity and 96.4\% specificity. These findings indicate the presence of previously unrecognized oral mucosal reflectance abnormalities in unaffected ACH parents of ACH children.