TBC1D7 Mutations are Associated with Intellectual Disability, Macrocrania, Patellar Dislocation and Celiac Disease.
TBC1D7 forms a complex with TSC1 and TSC2 that inhibits mTORC1 signaling and limits cell growth. Mutations in TBC1D7 were reported in a family with intellectual disability and macrocrania. Using exome sequencing we identified two sisters homozygote for the novel c.17_20delAGAG, p.R7TfsX21 TBC1D7 truncating mutation. In addition to the already described macrocephaly and mild intellectual disability, they share osteo-articular defects, patella dislocation, behavioral abnormalities, psychosis, learning difficulties, celiac disease, prognathism, myopia and astigmatism. Consistent with a loss-of-function of TBC1D7 the patient’s cell lines show an increase in the phosphorylation of 4EBP1, a direct downstream target of mTORC1 and a delay in the initiation of the autophagy process. This second family allows enlarging the phenotypic spectrum associated with TBC1D7 mutations and defining a TBC1D7 syndrome. Our work reinforces the involvement of TBC1D7 in the regulation of mTORC1 pathways and suggests an altered control of autophagy as possible cause of this disease. This article is protected by copyright. All rights reserved.
This article is protected by copyright. All rights reserved.
TBC1D7, TSC, exome sequencing, intellectual disability, mTORC1