1 in 200,000 male infants. Costeff syndrome is another name for 3-methylglutaconic aciduria type III. This disorder is characterized mainly by the degeneration of the optic nerves, which carry information from the eyes to the brain. Sometimes other nervous system problems occur, such as an inability to maintain posture, poor muscle tone, the development of certain involuntary movements (extrapyramidal dysfunction), and a general decrease in brain function (cognitive deficit). The incidence of 3-methylglutaconic aciduria type III is about 1 in 10,000 newborns in the Iraqi Jewish population. This disorder is extremely rare in all other populations. The signs and symptoms of 3-methylglutaconic aciduria type IV are variable and overlap with types I-III. The incidence of 3-methylglutaconic aciduria type IV is unknown. Treatment There is no known treatment or cure. Epidemiology 3-Methylglutaconic aciduria seems to be most prevalent amongst the Jewish population of Iraq. However, a high concentration of one type is found in the Saguenay-Lac-Saint-Jean region of Canada. This suggests that the disease is more frequent in insular areas where there is more likelihood that both parents are carriers, a higher birth rate, and a greater frequency of consanguineous marriages. As all types of 3-Methylglutaconic aciduria are known to be genetic diseases and show a recessive inheritance pattern, consanguineous marriages (in which both partners may have inherited the mutation from the same ancestor) increase the chances of having a baby with the condition. References External links Phospholipid metabolism disorders