title: Xq26.2-q26.3 microduplication in two brothers with intellectual disabilities: clinical and molecular characterization.
abstract: Partial duplications involving the long arm of the X chromosome are associated with mental retardation, short stature, microcephaly, hypopituitarism and a wide range of physical findings. We identified an inherited Xq26.2-Xq26.3 duplication in two brothers with severe mental retardation, hypotonia, growth delay, craniofacial disproportion and dental malocclusion. Chromosome analysis was normal and multiplex ligation-dependent probe amplification analysis detected duplication on Xq26. Further characterization by array comparative genomic hybridization and quantitative PCR helped to determine proximal and distal duplication breakpoints giving a size of approximately 2.8 Mb. The duplication encompasses 24 known genes, including the X-linked mental retardation genes ARHGEF6, PHF6, HPRT1 and SLC9A6. Clinical and molecular characterization of Xq duplications will shed more light into the phenotypic implication of functional disomy of X-chromosome genes.
authors.affiliation: CIBER de Enfermedades Raras, Barcelona, Spain.
authors.forename: Irene
authors.initials: I
authors.lastname: Madrigal
authors.forename: Miguel
authors.initials: M
authors.lastname: Fernández-Burriel
authors.forename: Laia
authors.initials: L
authors.lastname: Rodriguez-Revenga
authors.forename: Jose Carlos
authors.initials: JC
authors.lastname: Cabrera
authors.forename: Milagros
authors.initials: M
authors.lastname: Martí
authors.forename: Antonio
authors.initials: A
authors.lastname: Mur
authors.forename: Montserrat
authors.initials: M
authors.lastname: Milà
mesh_terms: D000293:Adolescent; D002352:Carrier Proteins / Q000235:genetics; D041321:Chromosomes, Human, X / Q000235:genetics*; D020440:Gene Duplication; D050172:Genes, X-Linked; D020662:Guanine Nucleotide Exchange Factors / Q000235:genetics; D006801:Humans; D007041:Hypoxanthine Phosphoribosyltransferase / Q000235:genetics; D008297:Male; D038901:X-Linked Intellectual Disability / Q000235:genetics*; D012097:Repressor Proteins; D064067:Rho Guanine Nucleotide Exchange Factors; D012729:Sex Chromosome Aberrations; D025064:Sex Chromosome Disorders / Q000235:genetics; D017923:Sodium-Hydrogen Exchangers / Q000235:genetics; D014314:Trisomy / Q000235:genetics; D055815:Young Adult
chemical_list: C576603:ARHGEF6 protein, human; D002352:Carrier Proteins; D020662:Guanine Nucleotide Exchange Factors; C502542:PHF6 protein, human; D012097:Repressor Proteins; D064067:Rho Guanine Nucleotide Exchange Factors; C445316:SLC9A6 protein, human; D017923:Sodium-Hydrogen Exchangers; D007041:Hypoxanthine Phosphoribosyltransferase