# Mutational Profile and Retinal Phenotypes of PCARE-Related Cone-Rod Dystrophies in a Mexican Cohort

## TL;DR

This study identifies new genetic mutations in a Mexican group with retinal disease and confirms a shared pattern of vision loss.

## Contribution

The study reports three novel PCARE pathogenic variants and expands the known mutational profile of PCARE-related retinal dystrophies.

## Key findings

- Six different PCARE pathogenic alleles were identified, including three novel mutations.
- Eighty-two percent of PCARE alleles in the cohort carried one of three specific mutations.
- All patients exhibited a cone-rod dystrophy pattern despite phenotypic variations.

## Abstract

The aim of the study is to describe the genotype and phenotype of a Mexican cohort with PCARE-related retinal disease.

The study included 14 patients from 11 unrelated pedigrees with retinal dystrophies who were demonstrated to carry biallelic pathogenic variants in PCARE. Visual assessment methods included best corrected visual acuity, color fundus photography, Goldmann visual field test, kinetic perimetry, dark/light adapted chromatic perimetry, full-field electroretinography, autofluorescence imaging, and spectral domain-optical coherence tomography imaging. Genetic screening was performed either by gene panel sequencing or by exome sequencing.

According to the results of multimodal imaging and functional tests, all 14 patients were diagnosed with cone-rod dystrophy. Six different PCARE pathogenic alleles were identified in our cohort, including three novel mutations: c.3048_3049del (p.Tyr1016∗), c.3314_3315del (p.Ser1105∗), and c.551A > G (p.His184Arg). Notably, alleles p.His184Arg, p.Arg613∗, and p.Arg984∗ were present in 18 of the 22 (82%) PCARE alleles from probands in our cohort.

Our work expands the PCARE mutational profile by identifying three novel pathogenic variants causing retinal dystrophy. While phenotypic variations occurred among patients, a cone-rod dystrophy pattern was observed in all affected individuals.