Biochemical composition of the glomerular extracellular matrix in patients with diabetic kidney disease

Table 3 Type IV collagen-related kidney disease

	Gene/location	Protein	Mutation	Risk of progression to end-stage kidney disease
X-linked Alport syndrome	COL4A5/X chromosome	α5 chain of type IV collagen	Hemizygous (males) or heterozygous (females) mutations	Hemizygous: 100%; Heterozygous: 25%
Autosomal recessive Alport syndrome	COL4A4 or COL4A3/2q36-37	α4 and α3 chains of type IV collagen	Biallelic (homozygous or compound heterozygous) mutations	100%
Autosomal dominant Alport syndrome	COL4A4 or/COL4A32q36-37	α4 and α3 chains of type IV collagen	Heterozygous mutations in the α4 or α3 chains	20% in patients with risk factors for progression
Digenic Alport syndrome	Two of the COL4A3-5 genes	Two of the α3-5 chains