Novel mutations and a severe neurological phenotype in Sjögren-Larsson syndrome patients from Iran

Sjögren-Larsson syndrome (SLS) is a rare autosomal recessive disorder characterized by ichthyosis, spasticity and intellectual disability. The disease is caused by mutations in the ALDH3A2 gene that encodes fatty aldehyde dehydrogenase. We describe 7 Iranian SLS patients from 5 unrelated consanguineous families. Sequencing of ALDH3A2 identified 4 novel mutations, including a 26-bp deletion (c.25_50del), small in-frame deletion (c.370_372del; p.G124del), a termination (p.Q35Ter) and a missense mutation (p.Lys211Glu). Bacterial expression of the p.Lys211Glu and p.G124del mutations showed little or no detectable enzyme activity. Three of the patients exhibited an unusual neuro-regressive clinical course associated with seizures, which may reflect the presence of unidentified genetic or environmental modifiers in this consanguineous population. This cohort represents the largest group of Iranian patients with molecularly confirmed SLS and expands the mutational and clinical spectrum of this disease.