Smith-Lemli-Opitz syndrome (SLO) is an inherited condition that impairs the body’s ability to make cholesterol correctly.
Symptoms include distinct facial features, a small head size, developmental delay or intellectual disability, and behavioral problems. SLO is also associated with different birth defects, including abnormal genitalia, cleft palate, heart defects, extra fingers, or fused toes.
This condition is caused by pathogenic (disease-causing) variants in the DHCR7 gene and exhibits autosomal recessive inheritance. This means that both parents must be carriers to have a 25% chance to have a child with the condition. The risk of being a carrier is based on a person’s ancestry or ethnic background. For example, individuals of Ashkenazi Jewish descent have a 1 in 41 chance to be a carrier. Carriers typically do not experience any symptoms.