The c.1262A>G variant in SLC26A4 is a missense variant predicted to cause substitution of glutamine by arginine at amino acid 421 (p.Gln421Arg). The highest population minor allele frequency in gnomAD v2.1.1 is 0.003% (3/113084) in the European (non-Finnish) population, which is lower than the ClinGen Hearing Loss VCEP threshold (<0.007%) for PM2_Supporting, meeting this criterion (PM2_Supporting). The computational predictor REVEL gives a score of 0.954, which is above the threshold of 0.7, evidence that correlates with impact to SLC26A4 function (PP3). Another missense variant, c.1262A>C (p.Gln421Pro), at the same codon has been classified as likely pathogenic for autosomal recessive Pendred syndrome (PM5; PMID: 17718863, 23918157, 24224479, 28964290). The p.Gln421Arg variant has been reported in five individuals with hearing loss and inner ear abnormalities, which is highly specific for Pendred syndrome (PP4). Two individuals did not have a variant on the second allele identified (PMIDs: 23965030, 14679580). Two individuals were compound heterozygous for the CEVA haplotype, and one individual was compound heterozygous for a variant of uncertain significance, c.284G>A p.Gly95Glu. Phase for these individuals was unknown (0 PM3 points, PMID: 36833263). This variant was re-reviewed on 6.27.2023, and PM2 was downgraded to PM2_Supporting following the most recent specification criteria. Because no contradictory evidence was added, this variant was retained at likely pathogenic for autosomal recessive Pendrome syndrome based on the ACMG/AMP criteria applied, as specified by the ClinGen Hearing Loss VCEP: PM5, PM2_Supporting, PP3, PP4. (VCEP specifications version 2; 06.21.2023).