Using a combination of linkage mapping and massively parallel sequencing of the X-chromosome exome, we identified an 18-bp deletion in exon 8 of the oral-facial-digital syndrome type 1 (OFD1) gene in a family with X-linked Joubert syndrome (JBTS10). The deletion results in an in-frame deletion of six amino acids. New features not noted in the two previously reported cases of X-linked Joubert syndrome include the presence of polycystic kidney disease, polymicrogyria and hydrocephalus. Our study further underlines the power of genetic mapping combined with massively parallel sequencing as a powerful tool for novel disease gene and mutation discovery. ; Michael Field, Ingrid E Scheffer, Deepak Gill, Meredith Wilson, Louise Christie, Marie Shaw, Alison Gardner, Georgie Glubb, Lynne Hobson, Mark Corbett, Kathryn Friend, Saffron Willis-Owen and Jozef Gecz