Molecular Vision: Štabuc-Šilih, Mol Vis 2009; 15:2848-2860. Table 7

Table 7. Prediction of effect of substitution polymorphisms found in KC and healthy population.

COL4A3 polymorphism	PolyPhen prediction (score)	SIFT prediction (score)
G43R	possibly damaging (1.800)	not tolerated (0.00)
P141L	probably damaging (2.250)	tolerated (0.40)
E162G	benign(0.024)	tolerated (0.64)
D326Y	probably damaging (2.025)	tolerated (0.08)
H451R	benign (1.426)	tolerated (0.54)
P574L	probably damaging (2.250)	tolerated (0.19)
COL4A4 polymorphism	PolyPhen prediction (score)	SIFT prediction (score)
P482S	benign (1.125)	tolerated (0.71)
G545A	benign (1.350)	not tolerated (0.01)
M1327V	benign(0.017)	tolerated (0.13)

The PolyPhen (Polymorphism Phenotyping) tool predicts the possible impact of an amino acid substitution on the structure and function of a human protein using straightforward physical and comparative considerations. The SIFT (Sorting Intolerant From Tolerant) tool predicts whether an amino acid substitution will affect the protein function; based on sequence homology and the physical properties of amino acids it calculates the potential impact of the amino acid change (score lower than 0.05 is considered potentially damaging).