Background: Keratoconus (KC) is usually bilateral, noninflammatory
progressive corneal ectasia in which the cornea becomes progressively thin and conical.
Despite the strong evidence of genetic contribution in KC, the etiology of KC is not
understood in most cases.
Methods: In this study, we used whole-exome sequencing to identify the genetic cause
of KC in two sibs in a consanguineous family. The Homozygous frameshift variant
NM_001253826.1:c.60delC;p.Leu21Cysfs*6 was identified in the gene Nacetylgalactosaminyltransferase
14 (GALNT14). The variant does not exist in all public
databases neither in our internal exome database. Moreover, no database harbours
homozygous loss of function variants in the candidate gene.
Result: GALNT14 catalyses the initial reaction in O-linked oligosaccharide biosynthesis,
the transfer of an N-acetyl-D- galactosamine residue to a serine or threonine residue on
target proteins especially Mucins.
Conclusion: As alterations of mucin’s glycosylation are linked to a number of eye
diseases, we demonstrate in this study an association between the truncated protein
GALNT14 and KC.