Decreased expression of miR-122 in pterygium might result in abnormal cell apoptosis via its regulation of the expression of Bcl-w, and subsequently contribute to the development of pterygium.
In our patient, compound heterozygosity with PLOD2 mutations is associated with a clinical phenotype distinctive from classic BRKS2 indicating that when COL1A1 and COL1A2 mutation testing is negative for OI without congenital contractures or pterygia, atypical BRKS should be considered.
Bruck syndrome type 2 (BRKS2; MIM:609220) is a rare form of autosomal recessive OI caused by biallelic PLOD2 variants and is associated with congenital joint contractures with pterygia.
There were no significant differences between pterygium and control groups in age, sex, and distribution of genotype and allelic frequency of VEGF-460 polymorphism.
Several researchers believe that pterygium is UV-related and that abnormal expression of p53 protein and infection with human papillomavirus (HPV) are risk factors for pterygium, but their experiments have been inconclusive.
Other findings in pterygium include the frequent detection of HPV DNA, ocular surface changes such as the overexpression of various proteins, including defensins and phospolipases D, as well as the up-regulation of growth factors, such as bFGF or VEGF.