Partial KCNQ1OT1 hypomethylation: A disguised familial Beckwith-Wiedemann syndrome as a sporadic adrenocortical tumor

Dorra H'mida Ben-Brahim; Sabeur Hammami; Marwa Haddaji Mastouri; Saoussen Trabelsi; Maroua Chourabi; Sihem Sassi; Soumaya Mougou; Moez Gribaa; Abdelfattah Zakhama; Mohamed Neji Guédiche; Ali Saad

doi:10.1016/j.atg.2014.10.001

Partial KCNQ1OT1 hypomethylation: A disguised familial Beckwith-Wiedemann syndrome as a sporadic adrenocortical tumor

Appl Transl Genom. 2014 Oct 15:4:1-3. doi: 10.1016/j.atg.2014.10.001. eCollection 2015 Mar.

Affiliations

¹ Department of Cytogenetics and Reproductive Biology, Farhat Hached University Hospital, Sousse, Tunisia.
² Department of Pediatrics, Fattouma Bourguiba University Hospital, Monastir, Tunisia.
³ Department of Pathology, Fattouma Bourguiba University Hospital, Monastir, Tunisia.

Abstract

Beckwith-Wiedemann syndrome has a wide spectrum of complications such as embryonal tumors, namely adrenocortical tumor. Tumor predisposition is one of the most challenging manifestations of this syndrome. A 45-day old female with a family history of adrenocortical tumor presented with adrenocortical tumor. The case raised suspicion of a hereditary Beckwith-Wiedemann syndrome, therefore molecular analysis was undertaken. The results revealed partial KCNQ1OT1 hypomethylation in the infant's blood DNA which was associated with a complete loss of methylation in the infant's adrenocortical tumor tissue. It is unique for familial Beckwith-Wiedemann syndrome caused by KCNQ1OT1 partial hypomethylation to manifest solely through adrenocortical tumor. Incomplete penetrance and specific tissue mosaicism could provide explanations to this novel hereditary Beckwith-Wiedemann syndrome presentation.

Keywords: Adrenocortical tumor; Beckwith–Wiedemann syndrome; Hereditary; KCNQ1OT1.