title: De novo interstitial direct duplication of Xq21.1q25 associated with skewed X-inactivation pattern.
abstract: Genotype-phenotype correlation in women with an abnormal phenotype associated with a duplication of the long arm of the X chromosome remains unclear. We report on prenatal diagnosis and follow-up of a girl with an Xq duplication and dysmorphic features. The abnormal phenotype included growth retardation, hypotonia, and nystagmus. In order to improve the resolution of the cytogenetic analysis, we used both conventional and array-based comparative genomic hybridization to perform a global molecular cytogenetic analysis of the genome. These molecular cytogenetic analyses showed a direct duplication Xq21.1 --> q25 without other chromosomal abnormalities. This duplication was originating from the paternal X chromosome. Moreover, a skewed X-inactivation pattern was observed leading to a partial functional disomy of the chromosomal region Xq21.1q25. This report and review of the literature suggest that functional disomy for chromosome X could explain the abnormal phenotype. In prenatal diagnosis, this can have implication for patient management and genetic counseling.
authors.affiliation: Biologie et Génétique de la Reproduction, AP-HP Hôpital Antoine Béclère, 92140 Clamart, France. gerard.tachdjian@abc.ap-hop-paris.fr
authors.forename: G
authors.initials: G
authors.lastname: Tachdjian
authors.forename: A
authors.initials: A
authors.lastname: Aboura
authors.forename: M
authors.initials: M
authors.lastname: Benkhalifa
authors.forename: I
authors.initials: I
authors.lastname: Creveaux
authors.forename: L
authors.initials: L
authors.lastname: Foix-Hélias
authors.forename: J F
authors.initials: JF
authors.lastname: Gadisseux
authors.forename: O
authors.initials: O
authors.lastname: Boespflug-Tanguy
authors.forename: M
authors.initials: M
authors.lastname: Mohammed
authors.forename: P
authors.initials: P
authors.lastname: Labrune
mesh_terms: D001483:Base Sequence; D041321:Chromosomes, Human, X; D017931:DNA Primers; D004303:Dosage Compensation, Genetic; D005260:Female; D018628:Gene Dosage; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007231:Infant, Newborn; D007621:Karyotyping; D009693:Nucleic Acid Hybridization; D020411:Oligonucleotide Array Sequence Analysis
chemical_list: D017931:DNA Primers