Both heavy and light chains bear Asn-linked glycans, on three distinct glycosylation sites each.

In addition to the following diseases, low factor I is associated with recurrent bacterial infections in children.

Research suggests that mutations in the CFI gene contribute to development of age-related macular degeneration.

[18] This contribution is thought to be due to the dysregulation of the alternative pathway, leading to increased inflammation in the eye.

[20] Heterozygous mutations in the serine protease domain of the CFI gene account for 5-10% of cases.