Crygs, the gene for gammaS-crystallin, is crucial for maintaining lens transparency. GammaS-crystallin is a monomeric betagamma-crystallin, which is composed of two paired homologous domains, each with two Greek key motifs [4]. It may also have non-lens functions, as its expression has been detected in non-lens tissues such as the retina and cornea, potentially acting as a stress-related protein in the eye [5].

Mutations in Crygs are associated with various cataract-related phenotypes. In a Chinese family, a G57W mutation of CRYGS was found to be associated with autosomal dominant pulverulent cataracts [1]. A missense mutation c.199T>A, p.(Tyr67Asn) in CRYGS was identified in a five-generation Chinese family with autosomal dominant nuclear congenital cataracts, and this substitution was predicted to affect the protein's structure and translocation [2]. In mice, a temperature-sensitive mutation of Crygs in the Opj cataract led to disrupted fiber cell morphology and loss of maturing fiber cell nuclei, suggesting a loss of gammaS-crystallin function in maintaining cytoarchitecture [3]. The G18V mutation in human gammaS-crystallin associated with autosomal dominant cortical progressive cataract was shown to increase the protein's sensitivity to thermal and chemical stress, consistent with progressive cataract formation in family members carrying this mutation [4]. In Crygs-mutated cataractous mice, the mutant gene led to changes in BFSP/filensin and other crystallins, which may secondarily lead to cataract formation [6].

In conclusion, Crygs plays a vital role in maintaining lens transparency and the cytoarchitecture of the lens. Research on Crygs-mutated mouse models has significantly contributed to understanding the molecular mechanisms underlying cataract formation, providing insights into the genetic basis of this common eye disorder.