Abstract
Abstract: :
Purpose: To investigate for the presence of abnormal forms of crystallins occurring in idiopathic infantile cataracts. Method: Lens tissue from seven infantile cataract cases (age six weeks to nine months) and one normal fetal lens (33 weeks gestation) were analyzed using MALDI-TOF (matrix assisted laser desorption ionization with time of flight analysis) mass spectrometry to accurately determine the molecular weights (MWt) and fractions of the crystallin subunits ( A, B, A1, A3, A4, B1, B2, C, D, S) in each specimen. Results: Of the seven infantile cataract specimens, four revealed crystallin molecular weights and fractions similar to that of the normal foetal lens and in the previously published literature. Three cases however possessed similarly different crystallin patterns with reduced fractions of B2 (MWt 23125-23170) and A (MWt 19813-19824), and a significant expression of a protein of novel molecular weight (MWt 23724-23732). Conclusion: This initial study has identified a significantly occurring aberration in lens protein composition, and may identify a common abnormality in idiopathic infantile cataracts, which have been considered an etiologically diverse condition. Further studies involving protein and lens/somatic DNA analysis on these and subsequently collected tissue aims to elucidate the natures of this novel crystallin (MWt 23724-23732) and A/ B2 reductions.
Keywords: 338 cataract • 356 clinical (human) or epidemiologic studies: systems/equipment/techniques • 527 protein structure/function