Diseases may be confused with Alport syndrome simply because they are familial and not polycystic, because they are associated with deafness, or because they have an abnormal-looking GBM. Sometimes they will be Alport Syndrome with unusual features, but at other times they may be one of the following:
|
|
|
|
|
| Alport syndrome, about 80% | COL4A5, X |
XLr
|
Basement membrane collagen |
| Alport syndrome, <20% | COL4A3/4, 2 |
Ar
|
Basement membrane collagen |
| Alport syndrome, less common | COL4A3/4, 2 |
Ad
|
Basement membrane collagen |
| Fechtner syndrome | MYH9, 22 |
Ad
|
The gene is a non-muscle myosin heavy chain. Progressive renal failure (but is there any BM abnormality??), associated with deafness, macrothrombocytopenia, wbc inclusions. Various names for variants: eg. Epstein is the same without wbc abnormalities; Sebastian is the haematological abnormalities alone. May-Hegglin anomaly is the same as Sebastian syndrome but with structurally different wbc inclusions. Check any of these in OMIM |
| Thin basement membrane disease | COL4A3/4, 2 |
|
Basement membrane collagen. Probably a minority of families are carriers of autosomal recessive Alport syndrome, but a significant proportion are. Unlike female carriers of COL4A5 mutations, there are not areas of thickening/ basket weave, just global thinning of the GBM. |
| Mitochondrial DNA mutations | A3245G esp. |
|
May cause sensorineural deafness and progressive renal disease (Fanconi syndrome, tubulointerstitial nephritis, occasionally FSGS). These mutations are also assoc with diabetes mellitus and with the MELAS syndrome ( mitochondrial myopathy (inc. HOCM and other cardiac), encephalopathy, lactic acidosis, stroke-like episodes). However many of these manifestations may be subclinical or absent. |
| Branchio-oto-renal dysplasia | EYA1, 8 |
Ad
|
EYA is the "eyes absent" gene in Drosophila. Mild or partial forms have presented in adult life. EYA 2,3 or other genes may be implicated in other families. |
| Other inherited GBM disorders | various |
-
|
See Single Gene Disorders |
| Renal tubular acidosis with deafness | ATP6B1 |
Ar
|
. |
| Other inherited glomerular diseases | various |
-
|
Just because they are familial |
Note that the deafness of Alport syndrome is not congenital, it comes from during late childhood or early adult life.
Link to OMIM (Online Mendelian Inheritance in Man) for further information on individual diseases.
Up to top of page
Back to Education home page
Back to EdREN home page
Page last updated