Bathing suit ichthyosis (BSI) is a rare variant of autosomal recessive lamellar 
ichthyosis due to transglutaminase-1 (TGase-1) gene mutations leading to a 
temperature sensitive phenotype. It is characterized by dark-grey or brownish 
scaling restricted to the 'bathing suit' areas, whereas the extremities and 
central face are almost completely spared. We report a 2-year-old African girl 
with BSI with ultrastructural and biochemical demonstration of TGase-1 
deficiency over the affected skin. TGase-1 gene analysis disclosed the 
homozygous p.R315L mutation, which may lead to a temperature sensitive 
dysfunction of the enzyme.