PMC6066270_01
Fundus photography of the proband. Mild macular atrophy (A) with mild peripheral bone spicule-like pigmentation in the periphery (B) at age 14 years in comparison with severe atrophic macular changes, waxy pallor of the optic disc (C), and more pronounced peripheral bone spicule-like pigmentation in the periphery (D) at age 22 years.
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At her last examination, she was 22 years old and had poor night vision and peripheral vision, bilateral visual acuity of 6/76, mild to moderate attenuation of arterioles, mild peripheral bone spicule-like pigmentation in the fundus, and no optic disc atrophy (Figure 1).
Optical coherence tomography showing severe thinning of the macula in both eyes at age 12 years, as demonstrated by the thickness being less than 1% of normal distribution (red) for both eyes.
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Optical coherence tomography showed severe thinning at the macula (Figure 2).
Genetic analysis of the proband. A: Sanger sequencing electropherograms showing (top to bottom) TULP1 reference sequence (NM_003322.3), paternal electropherogram showing wild-type sequence, maternal electropherogram revealing heterozygous duplication, c.524dupC (arrow), and proband electropherogram showing homozygous duplication (arrow) of the preceding C nucleotide. B: Single nucleotide polymorphism (SNP) array showing the absence of heterozygous calls on chromosome 6, corresponding to uniparental isodisomy.
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TULP1 gene (NM_003322.3) in the proband (Figure 3A). The genotype of the proband and the father were compared: Informative SNPs confirmed paternity and demonstrated no paternal inheritance of the whole of chromosome 6, confirming maternal isodisomy of this entire chromosome (Figure 3B).