Cholesterol and Antioxidant Treatment in Patients With Smith-Lemli-Opitz Syndrome (SLOS)

Phase 2

Recruiting

• Conditions: Smith-Lemli-Opitz Syndrome; Hearing Loss; Cone-Rod Dystrophy
• Interventions: Drug: Antioxidants; Drug: Cholesterol

• Registration Number: NCT01773278
• Lead Sponsor: University of Colorado, Denver

Brief Summary

Patients with biochemically confirmed SLOS are being treated with cholesterol supplementation and antioxidant medication. They are carefully monitored with visits to clinic, laboratory testing including cholesterol and 7-dehydrocholesterol levels, vitamin levels, blood counts and liver and kidney function. On a serial basis, no more often than once a year, the patients undergo a series of tests under anesthesia, including electroretinogram (ERG), brainstem audiometry (ABR), and ophthalmologic exam under anesthesia to follow pigmentary retinopathy.

Detailed Description

Smith-Lemli-Opitz Syndrome (SLOS) is an autosomal recessive disorder caused by a metabolic error in the final step of cholesterol biosynthesis, leading to cholesterol deficiency and accumulation of the cholesterol precursor, 7-dehydrocholesterol.Patients with SLOS display complex medical problems including growth failure, intellectual disability, behavioral disorders, progressive retinal dystrophy, hearing loss and photosensitivity. Dr Elias was one of the original geneticists who discovered the cause of this disorder in 1994, and ever since has been treating SLOS patients with cholesterol supplementation. In 2008, a second medication called AquADEKS, a mixture of vitamins and other compounds with antioxidant properties was added to the treatment regimen. AquADEKS has since been replaced with a comparable medication named DEKAS plus.The purpose of the DEKAS plus is to allow treatment with antioxidant medications in an effort to prevent retinal degeneration, hearing and skin problems associated with SLOS.

This protocol has been approved by the Colorado Multiple Institutional Review Board and supported by the Clinical Translational Research Center (CTRC) since 2001. The following updated information is available about the protocol:

1. Research has revealed that oxysterols are toxic compounds made from the cholesterol precursor, 7-dehydrocholesterol. These oxysterol compounds are severely neurotoxic and toxic to the retina, and treatment with antioxidants may help lower their levels, resulting in slowing of retinal deterioration. Testing of oxysterol levels in patients with SLOS is now ongoing, in collaboration with a laboratory at University of Washington in Seattle (Dr Libin Xu). It is hoped that testing of oxysterol levels in blood may help provide more updated info to help guide treatment.

Study Timeline

• Study Start: 2008-12
• Study First Submitted: 2012-12-03
• Study First Submitted QC: 2013-01-17
• Study First Posted: 2013-01-23
• Status Verified: 2024-05
• Last Update Submitted: 2024-05-07
• Last Update Posted: 2024-05-08
• Primary Completion: 2025-12
• Study Completion: 2025-12

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 100

Inclusion Criteria

• Clinical diagnosis of Smith-Lemli-Opitz Syndrome
• Elevated levels of 7-dehydrocholesterol and 8-dehydrocholesterol
• Must be able to travel to Children's Hospital Colorado annually
• Must have insurance coverage for ERG/ABR studies

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Exclusion Criteria

• absence of detectable 7-dehydrocholesterol/8-dehydrocholesterol
• allergy to Antioxidant medication

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Study & Design

• Study Type: INTERVENTIONAL
• Study Design: SINGLE_GROUP

Arm && Interventions

Group	Intervention	Description
antioxidant effects on retinal function	Antioxidants	Patients with SLOS will be treated with both cholesterol supplementation and antioxidants. Retinal function will be followed by serial electroretinogram (ERG) testing and pigmentary retinopathy will be followed by Serial Ophthalmologic exams under anesthesia
antioxidant effects on hearing	Antioxidants	Patients with SLOS will be treated with cholesterol and antioxidant medication and their hearing will be followed by serial brainstem audiometry (ABR)
Antioxidant effect on Oxysterols	Antioxidants	Patients with SLOS will be treated with antioxidants and cholesterol. Blood oxysterol levels will be measured. Future focus will be on being able to use oxysterol levels to regulate antioxidant doses, and to determine which particular antioxidants might have the most benefit in lowering oxysterols
antioxidant effects on hearing	Cholesterol	Patients with SLOS will be treated with cholesterol and antioxidant medication and their hearing will be followed by serial brainstem audiometry (ABR)
antioxidant effects on retinal function	Cholesterol	Patients with SLOS will be treated with both cholesterol supplementation and antioxidants. Retinal function will be followed by serial electroretinogram (ERG) testing and pigmentary retinopathy will be followed by Serial Ophthalmologic exams under anesthesia
Antioxidant effect on Oxysterols	Cholesterol	Patients with SLOS will be treated with antioxidants and cholesterol. Blood oxysterol levels will be measured. Future focus will be on being able to use oxysterol levels to regulate antioxidant doses, and to determine which particular antioxidants might have the most benefit in lowering oxysterols

Primary Outcome Measures

Name	Time	Method
Change in Electroretinogram (ERG) results over time	1-2 year	ERG testing will be performed on an serial basis while the patient is being treated with antioxidants (AquADEKS), to follow the amplitude and latency time on ERG. Improvement would be determined by an increased amplitude and decreased latency time.

Secondary Outcome Measures

Name	Time	Method
Change in ABR (Auditory Brainstem response) testing over time	1-2 years	Patients will be followed serial with ABR to determine the latency time in Wave I, when treated with antioxidant medication

Trial Locations

Locations (1)

Children's Hospital Colorado; 🇺🇸 Aurora, Colorado, United States