A patient with Rothmund-Thomson syndrome and all features of RAPADILINO

Background: Mutations of the human helicase gene RECQL4 have been identified in a subset of patients with Rothmund-Thomson syndrome (RTS) and in children with the diagnosis of RAPADILINO syndrome (RAdial hypoplasia/aplasia, PAtellar hypoplasia/aplasia, cleft or highly arched PAlate, DIarrheal and DIslocated joints, Llttle size [> 2 SDs below the mean in height] and LImb malformation, and slender NOse and NOrmal intelligence). While many features of the 2 genetic disorders overlap, poikiloderma-a hallmark of RTS-has been described as generally absent in RAPADILINO syndrome. Observations: We report herein a patient with RTS who carries a truncating mutation and a newly identified missense mutation of RECQL4. The proband uniquely developed all criteria of RAPADILINO in addition to his prominent skin findings. Conclusions: Patients with RTS may possess all features of RAPADILINO. Consequently, a genetic approach to RTS and RAPADILINO could be beneficial. This approach may provide a better understanding of the wide variety of related phenotypic findings and improve prognostics.