Townes-Brocks Syndrome as Familial Isolated Bilateral Cup Ear Deformity: A Case Report

Townes-Brocks syndrome (TBS) is a rare autosomal dominant disorder caused by pathogenic variants in SALL1. Although classically characterized by external ear anomalies, anorectal malformations, and thumb/radial defects, its expressivity is highly variable and mild presentations may be overlooked. We report a 7-year-old boy presenting for cosmetic correction of bilateral cup ear deformities. Initial hearing screening and renal ultrasonography showed no abnormalities, and no other anomalies were identified on clinical examination. Detailed history-taking and construction of a three-generation pedigree revealed that the patient's father and paternal grandfather had similar bilateral auricular deformities, suggesting autosomal dominant familial transmission. Genetic testing of the proband and father demonstrated a heterozygous frameshift variant in exon 2 of SALL1 (c.1949del; p.Gly650AlafsTer46). The proband and his father underwent corrective otoplasty and achieved satisfactory early cosmetic outcomes. This family illustrates that SALL1-related TBS can present as an apparently isolated auricular phenotype. Familial congenital cup ear deformity, even when encountered in a cosmetic setting, should prompt careful family history-taking, consideration of genetic evaluation, counseling, and longitudinal surveillance.