Nevertheless, to date, since no genotype–phenotype correlation has yet been elucidated in HGPPS, possibly because of intra-familial variability of the cardinal features [38], and whereas HGPPS with scoliosis has been described without detectable mutations in ROBO3 gene [32], it is not possible to state that scoliosis is linked to ROBO3 mutations [46]. The gene discussed is ROBO3; the disease is horizontal gaze palsy with progressive scoliosis.