RESULTS
Whole exome sequencing was performed and analysed as previously described(Tham et al., 2015) and revealed a hemizygous four basepair deletion in EIF2S3, c.1394_1397del, located on the X-chromosome in both boys and their mother who was a healthy heterozygous carrier of the variant. The variant leads to a premature stop codon p.(Ile465Serfs*4) in the final exon of the gene (Fig. 2).