Sjogren-Larsson syndrome (SLS) is a rare genetic disease in which patients typically exhibit ichthyosis (dry, scaly skin), intellectual disability, spasticity, seizures and a distinctive maculopathy. The purpose of this study is to define the clinical spectrum and natural history of Sjogren-Larsson syndrome, and identify biomarkers that correlate with disease phenotype while establishing a registry for future investigations of biochemical pathogenesis and therapy.

The study will consist of a clinical component and a scientific component consisting of laboratory investigations of potentially useful biochemical (lipid and protein) markers. Up to 50 SLS patients of all ages, gender and ethnic origins will be enrolled. A detailed clinical evaluation will be performed to determine the presence and extent of disease involving the skin, nervous system and eyes. Clinical testing will include brain magnetic resonance imaging (MRI) and spectroscopy (MRS), electroencephalography (EEG), neurocognitive tests, ophthalmologic examination with retinal photographs and optical coherence tomography (OCT), photographs of the skin and tests of cutaneous transepidermal water loss. Laboratory investigations will include lipid analyses (e.g. fatty alcohols, farnesol, fatty acids, ether glycerolipids, etc.) of blood, skin and urine; proteomic analysis of skin (stratum corneum); and measurements of leukocyte fatty alcohol and farnesol oxidation. A skin biopsy (optional) will be obtained for electron microscopy, measurement of lanthanum perfusion (transepidermal water loss), and/or establishing keratinocyte cultures. Correlations between clinical abnormalities and laboratory measurements will be tested to identify the most useful biomarkers for future diagnostic and therapeutic studies. To characterize the progression of phenotypic features over time, patients <6 years of age will be followed yearly and patients ≥6 years of age will be followed every 3 years. In addition, a SLS patient registry will be established as a resource for future investigations in SLS.

Inclusion Criteria:

• The only eligibility criterion is that subjects have a genetically or biochemically confirmed diagnosis of Sjogren-Larsson syndrome.

Exclusion Criteria:

• The primary exclusion criteria are the patients' failure to consent or inability to travel to a STAIR site.

The study population will come from cohorts of Sjögren-Larsson syndrome patients currently followed at STAIR sites, from the RDCRN contact registry, and from the pool of new patients who directly contact STAIR sites or are referred to STAIR centers by their physicians.