Symptoms
Symptoms vary greatly but can include:
Physical: Small head size (microcephaly), distinctive facial features (e.g., droopy eyelids, broad nasal tip, small jaw), cleft palate, webbing of toes, extra fingers or toes (polydactyly), ambiguous genitalia in males, heart defects, kidney abnormalities, growth retardation.
Neurological: Intellectual disability, developmental delays, behavioral problems (e.g., hyperactivity, aggression, autism spectrum disorder), seizures, hypotonia (low muscle tone).
Feeding difficulties: Difficulty feeding or swallowing, failure to thrive.
Causes
SLOS is caused by mutations in the DHCR7 gene. This gene provides instructions for making the 7-DHCR enzyme. Mutations in this gene reduce or eliminate the enzyme's activity, leading to a buildup of 7-dehydrocholesterol (7-DHC) and a deficiency of cholesterol. It is inherited in an autosomal recessive pattern, meaning both parents must carry a copy of the mutated gene for a child to be affected.
Medicine Used
There is no cure for SLOS. Treatment focuses on managing symptoms and improving the quality of life.
Cholesterol supplementation: Supplementing with dietary cholesterol can help alleviate some symptoms, especially in milder cases.
Medications: Medications may be used to manage specific symptoms, such as seizures, behavioral problems, or gastrointestinal issues.
Surgery: Surgery may be necessary to correct physical abnormalities like cleft palate, heart defects, or polydactyly.
Is Communicable
No. SLOS is a genetic disorder and is not contagious or communicable. It cannot be spread from person to person.
Precautions
Since SLOS is a genetic condition, there are no specific precautions to prevent acquiring it. For parents who are carriers of the DHCR7 gene mutation, genetic counseling and prenatal testing (such as chorionic villus sampling or amniocentesis) can help assess the risk of having a child with SLOS.
How long does an outbreak last?
SLOS is not an infectious disease and does not have outbreaks. It is a chronic, lifelong condition.
How is it diagnosed?
Diagnosis typically involves:
Physical Examination: Identifying characteristic physical features.
Biochemical Testing: Measuring levels of 7-DHC and cholesterol in the blood. Elevated 7-DHC and low cholesterol levels are indicative of SLOS.
Genetic Testing: Confirming the diagnosis by identifying mutations in the DHCR7 gene.
Timeline of Symptoms
Symptoms can manifest at different stages:
Prenatal: Some severe cases can be detected prenatally through ultrasound (e.g., growth retardation, physical abnormalities) or biochemical testing of amniotic fluid or chorionic villi.
Newborn: Hypotonia, feeding difficulties, distinctive facial features, and genital abnormalities are often apparent at birth.
Infancy/Childhood: Developmental delays, intellectual disability, and behavioral problems become more evident as the child grows.
Important Considerations
Early Diagnosis and Intervention: Early diagnosis and intervention are crucial to maximizing the child's potential.
Multidisciplinary Care: Management of SLOS requires a multidisciplinary approach, involving specialists such as geneticists, pediatricians, neurologists, cardiologists, gastroenterologists, and therapists.
Family Support: Families affected by SLOS require significant support and resources to cope with the challenges of caring for a child with a complex genetic disorder. Support groups and online communities can be valuable sources of information and emotional support.
Variable Expression: The severity of SLOS can vary widely, even among individuals with the same DHCR7 gene mutations.