Banding pattern on polarized hair microscopic examination and unilateral polymicrogyria in a patient with steroid sulfatase deficiency.

BACKGROUND Several forms of ichthyosis are associated with neurologic manifestations, including Sjögren-Larsson syndrome, Refsum disease, and mental retardation-enteropathy-deafness-neuropathy-ichthyosis-keratoderma (MEDNIK) syndrome. We report a case of X-linked steroid sulfatase deficiency, ichthyosis, seizures, abnormal hair banding pattern, and unilateral polymicrogyria. OBSERVATIONS A 3-year-old Caucasian male with a history of ichthyosis since birth presented with generalized tonic seizures. Findings from a physical examination were remarkable for thin hair, retinitis pigmentosa, and poor dentition. Polarized light microscopic examination of all the hair samples demonstrated a banding pattern. Magnetic resonance imaging of the brain revealed left hemispheric polymicrogyria with decreased sulcal pattern and stable asymmetric dilation of the left lateral ventricle. Constitutional microarray revealed the typical approximately 1.5-Mb deletion of the steroid sulfatase gene. CONCLUSIONS Steroid sulfatase deficiency is a cause of X-linked ichthyosis; however, our patient also had retinitis pigmentosa, seizures, and abnormal hair findings. The presence of abnormal hair with a banding pattern on polarized microscopy may be helpful for diagnosis; however, this pattern is not specific to this disease. In addition, to our knowledge, the presence of a malformation of cortical development has not been previously reported in patients with steroid sulfatase deficiency.