Type of alpha (IV) chain | Genes | Location on the chromosome | Relevant mutation found in |
Alpha-1 | COL4A1 | 13 | Not known |
Alpha-2 | COL4A2 | 13 | Not known |
Alpha-3 | COL4A3 | 2q36-q37 | ARAS* |
Alpha-4 | COL4A4 | 2q36-q37 | ARAS |
Alpha-5 | COL4A5 | Xq22.3 | XLAS† |
Alpha-6 | COL4A6 | X | Leiomyomatosis‡ |
*Autosomal recessive AS (mutations spanning 5’ regions of COL4A5 and COL4A6 genes).
†X-linked AS: to date, more than 300 mutations of all types have been described in the COL4A5 gene.
‡Found in autosomal recessive AS.
AS, Alport’s syndrome.