Macular abnormalities such as incomplete foveal hypoplasia or staircase foveopathy are common in Alport syndrome.It may also be associated with retinitis pigmentosa. Leiomyomatosis
Diffuse leiomyomatosis of the oesophagus and tracheobronchial tree has been reported in some families with Alport syndrome. Symptoms usually appear in late childhood and include dysphagia, postprandial vomiting, substernal or epigastric pain, recurrent bronchitis, dyspnea, cough, and stridor. Leiomyomatosis is confirmed by computed tomography (CT) scanning or magnetic resonance imaging (MRI). Other abnormalities
Aortic dissection has been described very rarely in patients with early-onset disease. Leiomyomas, tumours of smooth muscle affecting the oesophagus and female genital tract, may occur in a rare overlap syndrome involving the adjacent COL4A5 and COL4A6 genes. Pathophysiology
Alport Syndrome is a relatively common genetic disorder affecting around 1 in 5,000-10,000 children,

Genetics
Alport syndrome is caused by mutations in COL4A3, COL4A4, and COL4A5, three of six human genes involved in basement membrane (type IV) collagen biosynthesis. Mutations in any of these genes prevent the proper production or assembly of the specialised type IV collagen 345 network which is an important structural component of basement membranes in the kidney, inner ear, and eye. It is also found in other locations, including the alveoli of the lungs. Basement membranes are thin, sheet-like structures that separate and support cells in many tissues. Type IV collagen 112 type is found in both vertebrates and invertebrates and is the major isoform in most human basement membranes.
Mannosidosis is a deficiency in mannosidase, an enzyme.There are two types:

Alpha-mannosidosis
Beta-mannosidosis

See also
Swainsonine


== References ==