Phenotype in X chromosome rearrangements: pitfalls of X inactivation study.
Fiche publication
Date publication
février 2007
Auteurs
Membres identifiés du Cancéropôle Est :
Dr JEANDIDIER Eric
Tous les auteurs :
Schluth C, Cossee M, Girard-Lemaire F, Carelle N, Dollfus H, Jeandidier E, Flori E
Lien Pubmed
Résumé
Objective. - X inactivation pattern in X chromosome rearrangements usually favor the less unbalanced cells. It is correlated to a normal phenotype, small size or infertility. We studied the correlation between phenotype and X inactivation ratio in patients with X structural anomalies. Patients and methods. - During the 1999-2005 period, 12 X chromosome rearrangements, including three prenatal cases, were diagnosed in the Laboratoire de Cytogenetique of Strasbourg. In seven cases, X inactivation ratio could be assessed by late replication or methylation assay. Results. - In three of seven cases (del Xp, dup Xp, t(X;A)), X inactivation ratio and phenotype were consistent. The four other cases showed discrepancies between phenotype and X inactivation pattern: mental retardation and dysmorphism in a case of balanced X-autosome translocation, schizophrenia and autism in two cases of XX maleness and MLS syndrome (microphthalmia with linear skin defects) in a case of Xp(21.3-pter) deletion. Conclusion. - Discrepancies between X inactivation ratio and phenotype are not rare and can be due to gene disruption, position effect, complex microrearrangements, variable pattern of X inactivation in different tissues or fortuitous association. In this context, the prognostic value of X inactivation study in prenatal diagnosis will be discussed. (c) 2006 Elsevier Masson SAS. All rights reserved.
Référence
Pathol Biol (Paris). 2007 Feb;55(1):29-36