Recessive XLI: high prevalence of neurological disorders. (1st October 2018)

• Record Type: Journal Article
• Authors: Rodrigo‐Nicolás, B.; Bueno‐Martínez, E.; Martín‐Santiago, A.; Cañueto, J.; Vicente, A.; Torrelo, A.; Noguera‐Morel, L.; Duat‐Rodríguez, A.; Jorge‐Finnigan, C.; Palacios‐Álvarez, I.; García‐Hernández, J.L.; Sebaratnam, D.F.; González‐Sarmiento, R.; Hernández‐Martín, A.
• Is Part Of: British journal of dermatology. Volume 179:Number 4(2018)
• Page Start: e180
• Page End: e180
• Publication Date: 2018-10-01
• Subjects: Dermatology -- Periodicals; Skin -- Diseases -- Periodicals; 616.5
• DOI: 10.1111/bjd.17182
• Languages: English
• ISSNs: 0007-0963

Abstract

Summary: This study from Spain concerns a group of genetic conditions called ichthyosis in which the skin is abnormally scaly. The particular type studied here is caused by a defective gene on the X chromosome and generally affects males, while female carriers have normal skin, hence the name X linked recessive ichthyosis (XLI). People with XLI lack steroid sulphatase (STS), an enzyme needed for normal skin exfoliation. Affected boys are otherwise healthy but may have undescended testes. Using hospital databases, the authors identified 30 males with XLI and obtained information from medical records and telephone interviews, aiming to clarify the clinical features of this relatively rare condition. Twenty‐nine had normal palms, a useful marker distinguishing XLI from other types of ichthyosis. Ten percent had surgery for undescended testis, 30% had attention‐deficit hyperactivity disorder (ADHD), and 13% had epilepsy, all three figures higher than in the general population (3%, 7% and 1% respectively). Epilepsy in patients with XLI only occurred in those missing the whole STS gene and may result from damage to neighbouring genes. By contrast, ADHD occurs in boys with small mutations within the STS gene and is probably caused by a direct biochemical effect of STS deficiency on neuropsychological functions. None of these patients had autism or intellectual disability. Interestingly other studies show that the drug methylphenidate, widely used to treat ADHD, reverses the biochemical defect caused by STS deficiency. As Professor Traupe from Germany points out in the accompanying commentary, XLI is more complex than we previously thought.