Double Xp11.22 deletion including SHROOM4 and CLCN5 associated with severe psychomotor retardation and Dent disease

Background: Here we report the clinical and molecular characterization of two Xp11.22 deletions including SHROOM4 and CLCN5 genes. These deletions appeared in the same X chromosome of the same patient.

Results: The patient is a six-year-old boy who presented hydrocephalus, severe psychomotor and growth retardation, facial dysmorphism and renal proximal tubulopathy associated with low-molecular-weight proteinuria, hypercalciuria, hyperaminoaciduria, hypophosphatemia and hyperuricemia. Standard and high resolution karyotypes showed a 46,XY formula. Array-CGH revealed two consecutive cryptic deletions in the region Xp11.22, measuring respectively 148 Kb and 2.6 Mb. The two deletions were inherited from the asymptomatic mother.

Conclusions: Array-CGH allowed us to determine candidate genes in the deleted region. The disruption and partial loss of CLCN5 confirmed the diagnostic of Dent disease for this patient. Moreover, the previously described involvement of SHROOM4 in neuronal development is discussed.