1：Experimental Design and Method Selection:

Whole-exome sequencing was performed on 56 samples from 16 families with diverse IRD phenotypes that had remained undiagnosed after screening for known mutations using genotyping-based microarrays. Variants in reported IRD genes were identified using WES and validated by Sanger sequencing. Custom TaqMan assays were used to screen for identified mutations in 193 unrelated indigenous Africans with IRDs.

2：Sample Selection and Data Sources:

Samples from indigenous African families were selected from the registry if DNA was available from at least three family members and if a proband had been screened using the appropriate microarray but no molecular diagnosis had been obtained.

3：List of Experimental Equipment and Materials:

Genomic DNA samples were quantified using the QuantiFluor dsDNA system. Whole-exome capture was performed using the Nextera Rapid Capture Expanded Exome kit, and sequences were obtained on a HiSeq2500 platform.

4：Experimental Procedures and Operational Workflow:

FastQC was used to confirm quality of sequencing, after which adapter indexes were removed using Trimmomatic. Reads were mapped to the human reference sequence using BWA, and GATK was used for variant calling, local realignment, base quality recalibration, and variant recalibration. Annotation of variants was performed with ANNOVAR.

5：Data Analysis Methods:

Variants with a minor allele frequency (MAF) of <0.1 in the 1000 Genomes Project were prioritized, as were exonic or splicing variants. The variants were subsequently selected based on cosegregation with the disease phenotype within each family.