Examples of spectratyping by age. Examples of spectratypings of 4 different VB families obtained from 4 different patients studied at different ages. The 2 left columns represent examples of normal spectratyping in 2 pDGS patients studied at 1 and 7 years, respectively. The 2 right columns represent examples of abnormal spectratyping, with a non-Gaussian and skewed profile in 2 pDGS patients studied at 13 and 16 years, respectively.