COL4A5 and Alport syndrome: Males hemizygous for a COL4A5 mutation, and individuals of either sex with homozygous or compound heterozygous COL4A3/4 mutations, are at risk of X-linked and autosomal recessive Alport Syndrome (AS) respectively, in which there is a high likely of ESRD within the first three decades of life, associated with sensorineural deafness and ocular abnormalities, including asymptomatic dot and fleck retinopathy and lenticonus.