Metacarpophalangeal pattern profile (MCPP) analysis of Noonan syndrome. D.D. Gale1, G.A. Dahir2, F.J. Meaney3, R. Kumar4, M.G. Butler4. 1) Col Allied Health & Nursing, Eastern Kentucky Univ, Richmond, KY; 2) University of Virginia, Charlottesville; 3) University of Arizona, Tucson; 4) The Children's Mercy Hospitals and Clinics, Kansas City, MO.
Metacarpophalangeal pattern profile (MCPP) analysis is an application of an anthropometric technique which provides a quantitative assessment of the amount and direction of abnormality in the hand skeleton. MCPP analysis was undertaken on 15 individuals (9 males; 6 females) with Noonan syndrome ranging in age from 0.1 to 36 years with a mean age of 11.6 years. This syndrome is associated with neck webbing, pectus excavatum, cryptorchidism, pulmonic stenosis, low posterior hairline, short stature and a particular facial appearance. The overall average Z score for the MCPP variables in individuals with Noonan syndrome was -2.1 and the range was -2.5 (metacarpal 2) to -1.5 (middle phalanx 5). The average pattern variability index, a measure of hand dysmorphogenesis, was 1.0. A value above 0.7 is considered abnormal. A Pearsonian correlation analysis was used to assess similarity between the mean pattern and each of the 19 individual patterns. Nine of 15 individuals with Noonan syndrome had significant positive correlations (p < 0.05) indicating homogeneity or similarity in hand patterns among Noonan syndrome subjects. A stepwise discriminant analysis was performed on 12 subjects with Noonan syndrome (8 males, 4 females; mean age = 7.3 years with age range of 0.1 to 13.5 years) and 41 controls (24 females, 17 males; mean age = 13.1 years with age range of 9.6 to 18 years). This analysis produced a discriminant function with age and one MCPP variable (middle phalanx 5) entered into the function. Although the hand pattern variability index indicated an abnormal MCPP, the multivariant analysis identified only one MCPP variable contributing to the overall difference between individuals with Noonan syndrome and the normative sample. The discriminant function will require testing with additional Noonan syndrome subjects for interpretation of its rate of correct classification of all individuals with Noonan syndrome.