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Smith-Lemli-Opitz syndrome


SLOS is a genetic disorder that affects the development of children both before and after birth. The syndrome was first described in 1964 in three boys with poor growth, developmental delay and a common pattern of congenital malformations including cleft palate, genital malformations and polydactyly (extra fingers and toes).

Although the name "RSH syndrome" (after the initials of the first three patients) was first used for the disorder, the syndrome is now better known by the names of the three geneticists who first described it. Although SLO/RSH has always been known as a genetic disorder, the cause was not known for the first 30 years after its description.

However, in 1993, scientists discovered that children with SLO/RSH are unable to make cholesterol, an essential nutrient that is not provided by the mother to the baby before birth. Because the body also makes most of its own cholesterol after birth, children with SLO/RSH continue to have trouble with development and general health after birth. The discovery of abnormal cholesterol metabolism in SLO/RSH has made possible not only a laboratory test for more precise diagnosis of SLO/RSH, but also provided a rationale for treatment of affected children.

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