Abstract
Purpose:
To report two novel mutations in the PIKFYVE gene, one frameshift and the other an interstitial deletion, associated with fleck corneal dystrophy (FCD) in two previously unreported individuals.
Methods:
A slit-lamp examination was performed prior to the collection of a saliva sample as a source of genomic DNA. Following DNA extraction, PCR amplification and automated sequencing of all 41 exons of PIKFYVE was performed. Copy number variation (CNV) detection was performed using quantitative PCR (qPCR).
Results:
Numerous, panstromal, grayish-white, punctate opacities were observed in both corneas of each individual, consistent with the diagnosis of FCD. Screening of PIKFYVE in the first proband demonstrated a novel heterozygous frameshift mutation in exon 19, c.3151dupA, which is predicted to encode for a truncated PIKFYVE protein, p.(Asp1052Argfs*18). Sanger sequencing of all exons and exon-intron boundaries of PIKFYVE in the second proband did not demonstrate a presumed pathogenic variant. However, qPCR revealed a novel heterozygous deletion involving exon 16[AA1] . Deletions involving PIKFYVE have been reported at a population frequency of 0.000105 (Database of Genomic Variation).<br /> <br />
Conclusions:
We report two novel PIKFYVE mutations associated with FCD: a heterozygous frameshift mutation (c.3151dupA), which is only the sixth frameshift mutation associated with FCD; and a heterozygous deletion, which is the first CNV associated with FCD.