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Inborn errors of metabolism

Smith-Lemli-Opitz syndrome (SLOS)

An inherited problem with making cholesterol. The body cannot produce enough cholesterol. Growth, development and the structure of some organs are affected.

Not part of the panel of Türkiye's National Newborn Screening Programme (heel-prick test). Source

Prepare an emergency card

This page is translated from the Turkish original.

This disease is followed through the “Inborn errors of metabolism” group.

Understanding the disease

This section has not yet been reviewed by a physician. It summarises patient information from sources such as MedlinePlus, Orphanet and the NHS in plain language. The disease can differ from person to person; talk to your doctor about diagnosis and treatment.

What happens in this disease?

Cholesterol is needed for cell membranes, the sheath around nerves and some hormones. In this disease, the last step of making cholesterol is disrupted. Cholesterol stays low and a harmful in-between substance builds up. This affects development starting in the womb.

Which symptoms can occur?

Symptoms vary greatly, from mild to severe.

  • A small head and slow growth
  • Joined second and third toes (in most)
  • Extra fingers or toes (sometimes)
  • Cleft palate and distinctive facial features
  • Intellectual disability, behavior and sleep problems
  • Differences in the heart, kidneys or genitals (sometimes)
  • Feeding difficulties and floppy muscles in infancy

How is it diagnosed?

A substance called 7-DHC is found to be high in the blood. The diagnosis is confirmed with a genetic test. This test looks at the DHCR7 gene. A screening test during pregnancy may raise suspicion. The diagnosis can be confirmed by testing the fluid around the baby.

Treatment and care

Care is planned by a team according to the person's needs. Cholesterol supplements may help with some symptoms and with growth. Surgery may be needed for differences in the palate, heart or genitals. Early special education, physiotherapy and behavioral support are important. If there is sensitivity to sunlight, the skin is protected. The doctor who follows the disease decides which treatment is suitable.

For the family: inheritance and genetic counselling

The disease is passed on through recessive inheritance. The mother and father are usually healthy carriers. For a couple who are both carriers, the chance of having an affected child is 1 in 4 in each pregnancy. In marriages between relatives, the chance of carrying the same gene is higher. Genetic counselling is recommended for the family.

Source: MedlinePlus Genetics: Smith-Lemli-Opitz syndrome · NORD: Smith-Lemli-Opitz Syndrome

Key facts

How is it inherited?
Autosomal recessive
When does it usually start?
Before birth, Infancy, Newborn period
Gene(s) involved
DHCR7

These facts are taken from Orphanet and MedlinePlus records (last checked: October 7, 2026). Frequency values are approximate ranges.

You are not alone: patient associations in Türkiye

Non-profit patient and family organizations in Türkiye working on this disease or disease group. Links are for information; Doktorclub is not affiliated with these organizations and does not endorse them.

We could not find a patient association specific to this disease.

For all rare diseases: Nadir Hastalıklar Federasyonu

Guides related to this disease

  • Rare disease at school · Telling the school, medicines and emergency plan, inclusion and BEP, support education room, absences, LGS/YKS arrangements, peer bullying.

Support and help

Doktorclub does not diagnose, recommend treatments or refer you to hospitals or doctors. These pages are meant to help you talk with your doctor.

News about SLOS

Clinical trials (ClinicalTrials.gov)

A clinical trial is a regulated study that tests whether a new treatment is safe and whether it works, in patients who volunteer. Most trials look for a certain age, genetic change and health condition. Taking part is voluntary.

This list is not a treatment recommendation. Treatments tested in phase 1–3 trials are investigational (experimental): their efficacy and safety have not yet been proven and they are not approved treatments. Taking part depends on each trial’s criteria and a physician’s assessment; the first step is to talk to the doctor who manages your care.

ClinicalTrials.gov currently lists no active interventional studies for this disease. Last checked: October 7, 2026.

See all studies on ClinicalTrials.gov · Joining clinical trials

Inborn errors of metabolism: other news

Medical codes (for talking with your doctor and finding sources)

These codes identify the disease in international classifications and databases. They can help when you talk with your doctor or look for reliable sources.

Orphanet code: ORPHA:818

No separate ICD-11 code; WHO classifies this disease under: 5C52.10

Codes checked against WHO ICD-11 and Orphanet on October 7, 2026.

This page provides general information and does not replace diagnosis or treatment. Talk to your doctor about symptoms, diagnosis and treatment.

The information on these pages is for general information only and does not replace medical advice. Talk to your doctor about diagnosis and treatment decisions. In an emergency in Türkiye, call 112.

Every update is based on an open source and labeled with its level of evidence. No advertising and no drug brand names. Our scientific principles

This page was translated from Turkish by the Doktorclub editorial team.