Brittle and sparse hair with normal cystine content caused by methionine deficiency?

Abstract

The unusual case of an 8-year-old girl with a hair disorder is presented, characterized by brittle, short and sparse hair. On polarizing microscopy the latter reveals a "tiger tail" pattern, whereas severe cuticular defects are detected on scanning electron microscopy. The patient's hair has a normal cystine content but is completely devoid of methionine and reveals distinct changes of its visoelastic parameters. It is presently unknown whether the lack of methionine may be implicated in the pathogenesis of this hair disorder, which to the best of our knowledge has not been previously described.