The presence of a heterozygous potentially deleterious C5orf42 (JBTS17) variant in the only c.428delGKIAA0586-homozygous patient reported by Bachmann-Gagescu et al. (2015), and the co-occurence of such variants in four ciliopathy genes in patient G2 (including a truncation in the JBTS gene KIF7) support the categorization of c.428delGKIAA0586 as a hypomorphic mutation of incomplete penetrance. Here, KIF7 is linked to ciliopathy.