Cold-induced sweating syndrome (CISS) is a rare autosomal recessive disorder characterized by excess sweating induced by cold exposure, camptodactyly and kyphoscoliosis. CISS is genetically heterogeneous. Deficiency of the CRLF1 or the CLCF1 gene function results in one of two clinically indistuinguishable disorders called CISS1 and CISS2, respectively. We present two Turkish brothers (22 and 13 years old) who had excess sweating induced by cold exposure, severe dorsal scoliosis, camptodactyly, reduced pain sensitivity and marfanoid habitus. The patients were homozygous and their parents heterozygous for a novel missense mutation c.413C>T (p.Pro138Leu) in CRLF1 gene. The cranial magnetic resonance imaging (MRI) of two patients also showed multiple small hyperintense lesions in the subcortical white matter. Similar MRI finding has also been reported in a Japanese woman with CISS1 and marfanoid habitus. The lesions found in the present cases showed no characteristic features. However, multiple small hyperintense lesions in subcortical white matter on T2 weighted and fluid attenuation inversion recovery (FLAIR) images may support the clinical diagnosis of CISS. (C) 2012 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.