EYA1 and BOR syndrome: For murine kidney development, the EYA1 gene is indispensable: Heterozygous EYA1 deficient mice exhibit renal abnormalities and conductive hearing loss similar to those observed in BOR syndrome, whereas mice with a homozygous knock-out of EYA1 lack ears and kidneys altogether, the latter being attributed to an absence of ureteric bud outgrowth and a subsequent failure of metanephric mesenchyme induction [7].