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Specific language impairment as the prominent feature in a patient with a low‐level trisomy 21 mosaicism
Author(s) -
PaoloniGiacobino A.,
Lemieux N.,
Lemyre E.,
Lespinasse J.
Publication year - 2007
Publication title -
journal of intellectual disability research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.941
H-Index - 104
eISSN - 1365-2788
pISSN - 0964-2633
DOI - 10.1111/j.1365-2788.2006.00912.x
Subject(s) - intellectual disability , trisomy , supernumerary , down syndrome , fluorescence in situ hybridization , karyotype , specific language impairment , biology , genetics , aneuploidy , phenotype , psychology , pathology , chromosome , medicine , developmental psychology , gene , anatomy
Background The extent and severity of the disabilities is variable among individuals with Down syndrome, although generally characterized by a range of physical and intellectual conditions, including language impairment. Whether the language deficit is due to the intellectual disability (ID) or associated to the supernumerary or portion of chromosome 21 is still debated. Methods Karyotyping was performed on blood lymphocyte and skin fibroblasts. Fluorescence in situ hybridization analysis was performed on cultured lymphocytes and buccal smear cells. Results The trisomy 21 (T21) mosaicism was characterized by 0.7–10% of mosaic cells in the different tissues, in a 14‐year‐old girl presenting an intellectual development within the normal range and specific language impairment (SLI) as the only prominent feature. Conclusion This case illustrates the wide range of phenotypical abnormalities possibly associated with T21 mosaicism. We propose that SLI is indeed a phenotypic trait specific to Down syndrome rather than subsequent to the ID most often associated to the syndrome.