In situ hybridization of known genes like ptchd3a, stc2a, robo4, sox9b and pcdh7b as well as novel transcripts like si:ch211-137a8.2 (the human orthologue that has been implicated in autosomal recessive nonsyndromic deafness 76) and zgc:194210 corroborated our RNAseq data and displayed either a complete loss or severe reduction of the respective gene in a quarter of the embryos (Fig. 2B-H). The gene discussed is ROBO4; the disease is hearing loss, autosomal recessive.