Spastic paraplegia in a 4-year-old boy

Abstract

Sjogren-Larsson syndrome (SLS) is an autosomal recessive disorder caused by the deficiency of fatty aldehyde dehydrogenase activity. It comprises a clinical triad of congenital ichthyosis, spastic paraplegia, and mental retardation. Seizures occur in 40% of patients. Some patients with SLS also exhibit minor features such as a pattern of glistening white dots in the fovea, defective development of tooth enamel, joint hyperextensibility, kyphoscoliosis, defective sweating and short stature. Brainstem auditory, visual, and short latency somatosensory evoked potentials may also be impaired in these children. The imaging findings of SLS consist of T2-hyperintense signal in the deep white matter with sparing of the subcortical U fibers, as seen in our patient. Myelination is not complete until 20 years of age in some subjects, and at age 4, incomplete myelination may also be present in the trigonal areas and the periventricular region in the frontal lobe. The basic defect of SLS is impairment in fatty alcohol oxidation because of deficient activity of alcoholnicotinamide adenine dinucleotide oxidoreductase (alcohol-NAD+ oxidoreductase), specifically the fatty aldehyde dehydrogenase component. As a consequence of this enzyme deficiency, long chain alcohols accumulate, which may lead to alteration of the epidermal water barrier and increased transepidermal water loss,