To understand the full contribution of LETM1 in WHS cases, further studies would be needed to investigate which phenotypes of WHS can be restored by the re-expression of LETM1. Apart from this, the identification of phenotypes that were consistent with both LETM1 haploinsufficiency in WHS and LETM1 bi-allelic variants will advance our understanding of the contribution of LETM1 in WHS. Here, LETM1 is linked to Wolf-Hirschhorn syndrome.