PMC4575904_01
Depiction of the PIKFYVE gene with associated functional domains found using PredictProtein. Mutations have been reported in exons 15, 16, 19, 20, and 24. The novel mutations that we report are indicated in red. Predicted binding sites and secondary structures are depicted in relation to the PIKFYVE protein. Functional domains are denoted by letters: A, zinc finger phosphoinositide kinase; B, Disheveld EGL-10, plextrin homology domains; C, beta-sheet winged helix DNA/RNA-binding motif; D, cytosolic chaperone CCTgamma apical domain-like motif; E, spectrin repeats; and F, C-terminal fragment similar to the common kinase core found in II beta phosphatidylinositol-4-phospohate 5-kinase. Binding regions are designated by shapes: Circles represent polynucleotide-binding regions, and diamonds represent protein binding regions. Secondary structures are denoted by blue and red boxes: Blue boxes represent beta strands, and red boxes represent alpha helices.
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The proband's mother (Figure 2A, individual I:1) and brother (Figure 2A, individual II:3) did not demonstrate stromal opacities in either cornea. However, the proband's sister (Figure 2A, individual II:1) demonstrated focal, gray-white stromal opacities diffusely distributed in the mid and posterior stroma of each eye.
Pedigree and PIKFYVE sequencing in a family with Fleck corneal dystrophy. A: Proband 1 is designated with an arrowhead. Filled symbols represent affected individuals, and question marks indicate individuals with undetermined affected status. B: Chromatograms demonstrate the presence of the c.3151dupA variant in proband 1 (individual II:2) and her affected sister (individual II:1); this variant was not present in the unaffected mother (individual I:1) and brother (individual II:3).
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A 40-year-old woman (proband 2; Figure 4A, individual II:2) was referred to one of the authors (AJA) for evaluation of bilateral corneal stromal opacities.
Slit-lamp photomicrograph of two individuals with Fleck corneal dystrophy. A: In proband 1, punctate discrete opacities are visible in retroillumination (arrows), and a few larger opacities are seen in the posterior stroma in direct illumination (arrowheads). B: In proband 2, discrete punctate grayish-white opacities are seen diffusely distributed in the corneal stroma (arrows).
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Slit-lamp examination revealed discrete, punctate, grayish-white stromal opacities, located primarily in the corneal mid-periphery OD and throughout the cornea OS (Figure 3B).
PMC4575904_02
Pedigree and PIKFYVE sequencing in a family with Fleck corneal dystrophy. A: Proband 1 is designated with an arrowhead. Filled symbols represent affected individuals, and question marks indicate individuals with undetermined affected status. B: Chromatograms demonstrate the presence of the c.3151dupA variant in proband 1 (individual II:2) and her affected sister (individual II:1); this variant was not present in the unaffected mother (individual I:1) and brother (individual II:3).
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A 40-year-old woman (proband 2; Figure 4A, individual II:2) was referred to one of the authors (AJA) for evaluation of bilateral corneal stromal opacities.
Slit-lamp photomicrograph of two individuals with Fleck corneal dystrophy. A: In proband 1, punctate discrete opacities are visible in retroillumination (arrows), and a few larger opacities are seen in the posterior stroma in direct illumination (arrowheads). B: In proband 2, discrete punctate grayish-white opacities are seen diffusely distributed in the corneal stroma (arrows).
mv-v21-1093-f3.jpg
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Slit-lamp examination revealed discrete, punctate, grayish-white stromal opacities, located primarily in the corneal mid-periphery OD and throughout the cornea OS (Figure 3B).
Pedigree of proband 2 and CNV analysis of PIKFYVE using qPCR. A: Proband 2 is designated with an arrowhead and the filled symbol represents the affected status of the individual. B: The CNV ratios were calculated between proband 2 and the unaffected control. PIKFYVE exons 15 and 16 demonstrated mean (minimum of 3 technical replicates) CNV ratios of approximately 0.5, which is evidence of a hemizygous deletion including these two exons. Error bars represent standard error of the mean.
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A 40-year-old woman (proband 2; Figure 4A, individual II:2) was referred to one of the authors (AJA) for evaluation of bilateral corneal stromal opacities. CNV ratios of approximately 0.5 were obtained for exons 15 and 16, suggestive of a heterozygous deletion in the range of approximately 2,500-9,000 nucleotides (Figure 4B).