In a screen for mutations in COL4A4 in 48 patients (of all ethnicities) with Thin Membrane Basement Disease, this variant was seen in 2 individuals. These patients were confirmed to not have Alport Syndrome. This variant was seen in 1/48 controls who did not have a renal biopsy, so they may not be actual controls. Glycine mutations in type IV collagen chains are often pathogenic, and pathogenicity cannot be excluded. The authors classify this as p. pathogenic. OR=2.
In a screen for mutations in COL4A3 and the COL4A3/COL4A4 promoter in 62 patients (of unreported ethnicities) with Thin Membrane Basement Disease, this variant was seen in one 30yo female along with the “known mutation” COL4A3 G695R. The COL4A3 variants were not seen in 50 controls, but it is not clear if this variant was sampled. The authors report that glycine mutations are typically causative for disease, but the status of this variant is not clear.