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. This evidence concerns the gene COL4A3 and Alport syndrome.