MSH: An autosomal dominant disorder manifested by various combinations of preauricular pits, branchial fistulae or cysts, lacrimal duct stenosis, hearing loss, structural defects of the outer, middle, or inner ear, and renal dysplasia. Associated defects include asthenic habitus, long narrow facies, constricted palate, deep overbite, and myopia. Hearing loss may be due to Mondini type cochlear defect and stapes fixation. (Jablonski's Dictionary of Syndromes & Eponymic Diseases, 2d ed),NCI: An autosomal dominant inherited syndrome caused by mutations in the EYA1, SIX1, and SIX5 genes. It is characterized by the abnormal development of the second branchial arch, resulting in the formation of branchial cleft cysts and fistulae, hearing loss and ear malformations, and renal abnormalities.