Clinically, both homozygosity for p.T721M and compound heterozygosity for p.T721M with another SLC26A4 mutation have been linked to non-syndromic DFNB4 or PS, as characterized by EVA, progressive or fluctuating severe-to-profound SNHI, and/or goiter18–21. The gene discussed is SLC26A4; the disease is autosomal recessive nonsyndromic hearing loss 4.