De novo mutation in the COL4A5 gene converting glycine 325 to glutamic acid in Alport syndrome.

Southern blot analysis of the COL4A5 gene in a 6 year old Italian Alport patient (proband VIZ) showed the loss of an MspI site that was present in the mother and control DNAs. PCR amplification and DNA sequencing revealed a single G-->A nucleotide change. The mutation results in substitution of a glutamic acid for a glycine residue at position 325 in the triple helical region of the alpha 5(IV) chain.