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Updated: Jun 8, 2026

Array Comparative Genomic Hybridization (Array CGH) for Detection of Genomic Copy Number Variants
Published on: February 21, 2015
Xq26.2-q26.3 microduplication in two brothers with intellectual disabilities: clinical and molecular characterization
Irene Madrigal1, Miguel Fernández-Burriel, Laia Rodriguez-Revenga
1CIBER de Enfermedades Raras, Barcelona, Spain.
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.
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