HomeGeneticsGeneCOL4A4 gene
Back to Gene
COL4A4 gene
Reviewed by Medicinsk Expert•Last updated: 2026-10-22•Gene

COL4A4 gene

The COL4A4 gene provides instructions for making the alpha4(IV) chain of collagen IV, a protein essential for the structural integrity of basement membranes in the kidneys, ears, and eyes.

Normal Function

The COL4A4 gene provides instructions for making the alpha4(IV) chain of collagen IV. This chain combines with two other types of alpha(IV) chains (the alpha3 and alpha5 chains) to form alpha345(IV) collagen molecules. These molecules form complex protein networks that constitute a large portion of basement membranes—thin, sheet-like structures that support cells in many tissues. These networks are particularly important in the basement membranes of the kidney, inner ear, and eye.

Health Conditions Related to Genetic Changes

Alport syndrome

Many variants in the COL4A4 gene can cause Alport syndrome, a condition characterized by kidney disease, hearing loss, and eye abnormalities. These variants either alter the structure of the alpha4(IV) collagen chain or severely decrease/prevent its production. This impairs the formation of alpha345(IV) collagen networks. In the kidney, this leads to the buildup of other types of collagen, resulting in scarring and eventual kidney failure.

  • Autosomal dominant Alport syndrome: Caused by a variant in one copy of the COL4A4 gene. Individuals typically experience kidney problems, including blood in the urine (hematuria), excess protein in the urine (proteinuria), and gradual loss of kidney function.
  • Autosomal recessive Alport syndrome: Caused by variants in both copies of the COL4A4 gene. Individuals may experience hearing loss and eye abnormalities in addition to kidney problems.

Other disorders

A variant in one copy of the COL4A4 gene can cause thin basement membrane nephropathy. People with this condition typically have blood in their urine (hematuria) but rarely progress to kidney failure.

Other Names for This Gene

  • alpha 4 type IV collagen
  • CA44
  • CO4A4_HUMAN
  • Collagen IV, alpha-4 polypeptide
  • collagen of basement membrane, alpha-4 chain
  • collagen type IV alpha 4
  • collagen, type IV, alpha 4

Frequently Asked Questions

lport syndrome linked to the COL4A4 gene can be inherited in two main ways. Autosomal dominant Alport syndrome occurs when only one copy of the COL4A4 gene has a variant, meaning there's a 50% chance for each child to inherit the condition from an affected parent. Autosomal recessive Alport syndrome requires variants in both copies of the COL4A4 gene. This means a child must inherit one variant copy from each parent, who are typically carriers and may not show symptoms themselves. Genetic counseling can help families understand their specific inheritance risks and options.
The long-term outlook for kidney disease caused by COL4A4 gene variants varies depending on the specific condition and inheritance pattern. For thin basement membrane nephropathy, the prognosis is generally good, with most individuals only experiencing microscopic hematuria and rarely progressing to kidney failure. For Alport syndrome, particularly the autosomal recessive form, kidney function often declines over time, potentially leading to end-stage kidney disease requiring dialysis or a kidney transplant. Management typically involves medications to control blood pressure and reduce protein in the urine, such as ACE inhibitors or ARBs, to slow the progression of kidney damage. Regular monitoring of kidney function, hearing, and eyes is also essential.
The earliest and most common sign of kidney problems related to COL4A4 gene variants, such as in Alport syndrome or thin basement membrane nephropathy, is blood in the urine (hematuria), which may not always be visible without a microscope. Other early signs can include excess protein in the urine (proteinuria), which might be detected during routine urine tests. In more severe cases, especially with autosomal recessive Alport syndrome, hearing loss and specific eye abnormalities might also develop, often becoming noticeable in childhood or adolescence. Regular monitoring by a doctor is crucial to detect these signs early.
Source: MedlinePlus, National Library of Medicine

MedlinePlus brings together authoritative health information from the National Library of Medicine (NLM), the National Institutes of Health (NIH), and other government agencies and health-related organizations.

kontakt@hittavard.se

Ⓒ 2024. Alla rättigheter förbehålls av juxt ab

Sök
Om ossVillkor och policyVanliga frågorKontakta oss