The Human Phenotype Ontology (HPO) provides the following list of features that have been reported in people with this condition. Much of the information in the HPO comes from Orphanet, a European rare disease database. If available, the list includes a rough estimate of how common a feature is (its frequency). Frequencies are based on a specific study and may not be representative of all studies. You can use the MedlinePlus Medical Dictionary for definitions of the terms below.
|Signs and Symptoms||Approximate number of patients (when available)|
|Sensorineural hearing impairment||90%|
|Aplasia/Hypoplasia of the lens||50%|
|Edema of the lower limbs||50%|
|Abdominal situs inversus||7.5%|
|Abnormality of the macula||7.5%|
|Feeding difficulties in infancy||7.5%|
|Nausea and vomiting||7.5%|
|Neoplasm of the colon||7.5%|
|Diffuse glomerular basement membrane lamellation||-|
|Stage 5 chronic kidney disease||-|
|X-linked dominant inheritance||-|
Type IV collagen is also an important component of the organ of Corti, an inner ear structure that transforms sound waves into nerve impulses for the brain. Alterations in type IV collagen may result in abnormal inner ear function, which can lead to hearing loss. In addition, type IV collagen plays a role in the eye, where it helps maintain the shape of the lens and the normal color of the retina. Mutations found in Alport syndrome may affect the shape of the lenses and the color of the retina.
In approximately 15 percent of cases, Alport syndrome results from mutations in both copies of the COL4A3 or COL4A4 gene and is inherited in an autosomal recessive pattern. The parents of an individual with the autosomal recessive form of this condition each have one copy of the mutated gene and are called carriers. Some carriers are unaffected and others develop a less severe condition called thin basement membrane nephropathy, which is characterized by hematuria.
Alport syndrome has an autosomal dominant pattern of inheritance in about 5 percent of cases. People with this form of Alport syndrome have one mutation in either the COL4A3 or COL4A4 gene in each cell. It remains unclear why some individuals with one mutation in the COL4A3 or COL4A4 gene have autosomal dominant Alport syndrome and others have thin basement membrane nephropathy.
Other aspects of the condition are addressed as needed. For instance, surgical repair of cataracts (cataract extraction), or repair of the anterior lenticonus in the eye may be needed. Loss of hearing is likely to be permanent. Counseling and education to increase coping skills can be helpful. Learning new skills such as lip reading or sign language may be of some benefit. Hearing aids are helpful. Young men with Alport syndrome should use hearing protection in noisy environments. Genetic counseling may be recommended because of the inherited pattern of the disorder.
Research helps us better understand diseases and can lead to advances in diagnosis and treatment. This section provides resources to help you learn about medical research and ways to get involved.
Nonprofit support and advocacy groups bring together patients, families, medical professionals, and researchers. These groups often raise awareness, provide support, and develop patient-centered information. Many are the driving force behind research for better treatments and possible cures. They can direct people to research, resources, and services. Many groups also have experts who serve as medical advisors. Visit their website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.
Living with a genetic or rare disease can impact the daily lives of patients and families. These resources can help families navigate various aspects of living with a rare disease.
These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.
2015 Collagen Gordon Research Conference and Gordon Research Seminar
Sunday, July 12, 2015 -
Friday, July 17, 2015
Location: New London, NH
Description: The 2015 Collagen GRC program will include invited and platform presentations as well as posters on (a) new data and concepts about the genetics, chemistry, biology and pathology of collagens; (b) advances in closely related areas of research, such as cell-matrix interactions, developmental biology and diseases of connective tissues, and bioengineering, that are relevant to the collagen field; (c) new and emerging technologies and approaches that may be applied to the collagen field.
Contact: Hung Tseng, Ph.D., (301) 496-0810, firstname.lastname@example.org
Co-funding Institute(s): National Institute of Arthritis and Musculoskeletal and Skin Diseases, Office of Rare Diseases Research
Questions sent to GARD may be posted here if the information could be helpful to others. We remove all identifying information when posting a question to protect your privacy. If you do not want your question posted, please let us know. Submit a new question
I was just diagnosed with Alport syndrome as an adult. Is this more common in those of Ashkenazi Jewish ancestry? See answer
What damage does Alport syndrome do to the kidney? See answer
My son rejected his first kidney transplant, can I be a donor since I am also a carrier? See answer
My sister's daughter has a son with X-linked Alport syndrome. Although my niece was not genetically tested as a carrier, her doctor assumed she is a carrier because of the large amount of blood in her urine. I have 2 sons and one daughter. I am told that my sons cannot be carriers and therefore don't have to worry about passing on this syndrome. Is that true? Also, how about my daughter? I have not been tested but if I do get tested and am not a carrier, then can I assume she is ok and will not pass down the syndrome to her children? Also, if I have my urine tested for hematuria and I don't have blood, can I assume that I am not a carrier? See answer
What causes Alport syndrome? Is it always inherited? See answer
I have been on hemodialysis for a year as a result of Alport syndrome. My two uncles died of kidney disease associated with this condition. What treatments are available for this condition? See answer