Fig. 1

Identification of the genetic cause of severe microcephaly in a Chinese family. a Family pedigree. Filled triangles with oblique lines indicate the two successive foetuses affected with severe microcephaly and terminated by therapeutic abortion. Arrow indicates the proband. Open symbols indicate clinically unaffected family members. Genotypes with respect to the RNU4ATAC gene are also provided where it was possible to determine them. wt, wild-type. b U4atac snRNA secondary structure elements, evolutionary conservation status of each nucleotide position and MOPD1-causative SNVs (adapted from [46]). The novel variant found in the present study, 29T>C, is highlighted in red and boxed. For a detailed description of the structure and function of U4atac, see Merico et al. [46] and references therein