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

Narjes Armanet,Dominique Pineau,Corinne Metay,François M Petit,Sophie Brisset,Philippe Labrune,Lucie Tosca,Michel Goossens,Federico Di Rocco,Georges Deschenes,Gérard Tachdjian

doi:10.1186/s13039-015-0107-x

Abstract

BackgroundHere 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.ResultsThe 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.ConclusionsArray-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.

Highlights

We report the clinical and molecular characterization of two Xp11.22 deletions including SHROOM4 and CLCN5 genes
We report the first clinical description and molecular characterization using array-CGH of a patient presenting two maternally inherited interstitial deletions of Xp11.22 in the same chromosome associated with severe psychomotor retardation and Dent disease
Taking into consideration that the asymptomatic mother carried the aberrant X chromosome inherited by the proband and by the male fetus aborted upon a subsequent pregnancy, X-inactivation assay was performed on the mother by analyzing the human androgen receptor CAG repeat polymorphism [14]

Summary

Conclusions

We report two familial interstitial deletions of Xp11.22 in the same X chromosome of the same patient presenting with hydrocephalus, severe growth and psychomotor retardation, renal proximal tubulopathy with. Besides the gene content of the two interstitial deletions and the most plausible candidates, one may not exclude position effects on neighboring genes which are not included in the deletions To our knowledge, this patient is the first description of a double Xp11.22 deletion causing a CLCN5 disruption and associated with a such characteristic renal proximal tubulopathy. The Xp11.22 deletion including CLCN5 and, the loss of CIC-5 exchanger allowed us to confirm the diagnosis of Dent disease. Our results strengthen the potential role of SHROOM4 in syndromic XLMR

Background

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Methods