Alport syndrome
| Alport syndrome | |
|---|---|
 |
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| Hearing loss effect of Alport syndrome in 13-year-old boy. | |
| Classification and external resources | |
| Specialty | medical genetics |
| ICD-10 | Q87.8 |
| ICD-9-CM | 759.89 |
| OMIM | 301050 104200 203780 300195 |
| DiseasesDB | 454 |
| MedlinePlus | 000504 |
| eMedicine | med/110 |
| Patient UK | Alport syndrome |
| MeSH | y D009394 y |
| GeneReviews | |
Alport syndrome is a genetic disorder affecting around 1 in 50,000 children, characterized by glomerulonephritis, end-stage kidney disease, and hearing loss. Alport syndrome can also affect the eyes, though the changes do not usually affect sight, except when changes to the lens occur in later life. Blood in urine is universal. Proteinuria is a feature as kidney disease progresses.
The disorder was first identified in a British family by University of Edinburgh Medical School graduate Cecil A. Alport in 1927,. Alport Syndrome once also had the label hereditary nephritis, but this is misleading as there are many other causes of hereditary kidney disease and 'nephritis'.
Alport syndrome is caused by an inherited defect in type IV collagen—a structural material that is needed for the normal function of different parts of the body. Since type IV collagen is found in the ears, eyes, and kidneys, this explains why Alport syndrome affects different seemingly unrelated parts of the body (ears, eyes, kidneys, etc.).
These descriptions refer to 'classic' Alport Syndrome, which usually causes significant disease from young adult or late childhood life. Some individuals, usually with milder mutations or 'carrier' status, develop disease later, or show only some of the features of classic disease.
Blood in urine is a usual feature of Alport Syndrome from early infancy, identifiable on urine dipsticks. In young children, episodes of visible (macroscopic) haematuria may occur. Protein begins to appear in urine as the disease progresses. This is now regarded as an indication for treatment with ACE inhibitors.
Alport syndrome can also cause hearing loss although some patients are not affected. Hearing in Alport syndrome patients is normal at birth. Hearing loss in affected patients develops progressively, usually at the stage when kidney function is normal, but there is substantial proteinuria. However, in some patients, hearing loss is only noted after kidney function has been lost. Characteristically the early changes are reduced abililty to hear high frequency sounds, 'high-tone hearing loss'. This becomes more severe and affects lower frequencies too. Hearing loss is not usually complete in Alport Syndrome, good communication is almost always possible with the use of hearing aids.
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Wikipedia