Jamra, Rami Abou/0000-0002-1542-1399; caglar, caner/0000-0002-5857-757X; Zaki, Maha/0000-0001-7840-0002; Caglayan, Ahmet/0000-0002-2332-322X; Campbell, Kevin/0000-0003-2066-5889 WOS: 000387529600015 PubMed: 27773428 Cobblestone lissencephaly (COB) is a severe brain malformation in which overmigration of neurons and glial cells into the arachnoid space results in the formation of cortical dysplasia. COB occurs in a wide range of genetic disorders known as dystroglycanopathies, which are congenital muscular dystrophies associated with brain and eye anomalies and range from Walker-Warburg syndrome to Fukuyama congenital muscular dystrophy. Each of these conditions has been associated with alpha-dystroglycan defects or with mutations in genes encoding basement membrane components, which are known to interact with alpha-dystroglycan. Our screening of a cohort of 25 families with recessive forms of COB identified six families affected by biallelic mutations in TMTC3 (encoding transmembrane and tetratricopeptide repeat containing 3), a gene without obvious functional connections to alpha-dystroglycan. Most affected individuals showed brainstem and cerebellum hypoplasia, as well as ventriculomegaly. However, the minority of the affected individuals had eye defects or elevated muscle creatine phosphokinase, separating the TMTC3 COB phenotype from typical congenital muscular dystrophies. Our data suggest that loss of TMTC3 causes COB with minimal eye or muscle involvement. Francois Wallace Mohanan fellowship; NIHUnited States Department of Health & Human ServicesNational Institutes of Health (NIH) - USA [R01GM077243, R01NS041537, R01NS048453, R01NS052455, P01HD070494]; Deutsche ForschungsgemeinschaftGerman Research Foundation (DFG) [AB393/2-1, AB393/2-2]; Simons Foundation Autism Research Initiative; Qatar National Research Fund [6-1463]; Paul D. Wellstone Muscular Dystrophy Cooperative Research Center [1U54NS053672] We thank the children and their families for their contributions to this study. This work was supported by the Francois Wallace Mohanan fellowship (J.J.); NIH grant R01GM077243 (J.A.-A.); Deutsche Forschungsgemeinschaft grants AB393/2-1 and AB393/2-2 (R.A.J.); NIH grants R01NS041537, R01NS048453, R01NS052455, and P01HD070494, the Simons Foundation Autism Research Initiative, and Qatar National Research Fund grant 6-1463 (T.B.-O., M.A., and J.G.G.); and Paul D. Wellstone Muscular Dystrophy Cooperative Research Center grant 1U54NS053672 (K.P.C.). K.P.C. and J.G.G. are Howard Hughes Medical Institute Investigators. We thank the Broad Institute (U54HG003067 to E. Lander and UM1HG008900 to D. MacArthur), the Yale Center for Mendelian Disorders (U54HG006504 to R. Lifton and M.G.), and the Gregory M. Kiez and Mehmet Kutman Foundation (M.G.). We acknowledge M. Gerstein, S. Mane, A.B. Ekici, and S. Uebe; the Yale Biomedical High Performance Computing Center for data analysis and storage; the Yale Program on Neurogenetics; and the Yale Center for Human Genetics and Genomics.