C1QTNF5 missense variant causing autosomal dominant gyrate atrophy-like choroidal dystrophy

Area of Science:

• Ophthalmology
• Medical Genetics
• Retinal Diseases

Background:

• Autosomal dominant gyrate atrophy-like choroidal dystrophy (adGALCD) is a rare chorioretinal dystrophy.
• The C1QTNF5 gene, specifically the c.538C>G; p.(Q180E) variant, has been recently implicated in adGALCD.
• AdGALCD shares phenotypic similarities with other retinal dystrophies but differs from late-onset retinal degeneration (L-ORD).

Purpose of the Study:

• To report a case of a simplex patient diagnosed with adGALCD.
• To confirm the association between the C1QTNF5 c.538C>G; p.(Q180E) variant and adGALCD.
• To characterize the clinical and genetic findings in a patient with adGALCD.

Main Methods:

• Comprehensive ophthalmic examinations including visual field testing and multimodal retinal imaging (OCT, fundus autofluorescence).
• Genetic analysis using whole exome sequencing.
• Clinical phenotyping of a 70-year-old female simplex patient.

Main Results:

• The patient presented with progressive concentric visual field defects and photophobia.
• Multimodal imaging revealed bilateral symmetric chorioretinal atrophy with foveal sparing and characteristic autofluorescence and OCT findings.
• Whole exome sequencing identified a heterozygous missense variant p.(Q180E) in the C1QTNF5 gene.

Conclusions:

• The findings confirm that the C1QTNF5 c.538C>G; p.(Q180E) missense variant is associated with autosomal dominant gyrate atrophy-like choroidal dystrophy (adGALCD).
• This case adds to the understanding of the genetic basis and clinical presentation of adGALCD.