title: Cryptic unbalanced translocation t(17;18)(p13.2;q22.3) identified by subtelomeric FISH and defined by array-based comparative genomic hybridization in a patient with mental retardation and dysmorphic features.
abstract: Molecular cytogenetics allows the identification of cryptic chromosome rearrangements, which is clinically useful in mentally retarded and/or dysmorphic individuals with normal results from conventional cytogenetics analysis. We report on a 3-year-old girl with mental retardation, growth deficiency, speech delay, and dysmorphic features including hypertelorism, upslanting palpebral fissures, midfacial hypoplasia, and posteriorly rotated ears. The G-banding analysis showed a 46,XX,t(3;8)(q26.2;p21.1)mat karyotype. However, her clinical features were suggestive of the 18q syndrome. Subtelomeric FISH analysis revealed a der(18) translocated material from chromosome 17. Array-based comparative genomic hybridization (array-CGH) with subtelomeric BAC and PAC clones confirmed the abnormality and refined the breakpoints to 18q22.3-qter and 17p13.2-pter (deletion of 8.5 Mb and duplication of 3.9 Mb, respectively). This case demonstrates the diagnostic utility of combining conventional cytogenetics with molecular chromosome analyses for the identification of subtle chromosome abnormalities.
authors: Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA.
authors: Kwei Shuai
authors: KS
authors: Hwang
authors: Margaret A
authors: MA
authors: Pearson
authors: Pawel
authors: P
authors: Stankiewicz
authors: P Alan
authors: PA
authors: Lennon
authors: M Lance
authors: ML
authors: Cooper
authors: Jessica
authors: J
authors: Wu
authors: Zhishuo
authors: Z
authors: Ou
authors: Wei-Wen
authors: WW
authors: Cai
authors: Ankita
authors: A
authors: Patel
authors: Sau Wai
authors: SW
authors: Cheung
mesh_terms: D000015:Abnormalities, Multiple / Q000235:genetics* / Q000473:pathology; D002675:Child, Preschool; D002871:Chromosome Banding; D002886:Chromosomes, Human, Pair 17 / Q000235:genetics*; D002887:Chromosomes, Human, Pair 18 / Q000235:genetics*; D005145:Face / Q000002:abnormalities*; D005260:Female; D015894:Genome, Human; D006801:Humans; D017404:In Situ Hybridization, Fluorescence / Q000379:methods; D008607:Intellectual Disability / Q000473:pathology*; D007621:Karyotyping; D009693:Nucleic Acid Hybridization / Q000379:methods; D013577:Syndrome; D016615:Telomere / Q000235:genetics; D014178:Translocation, Genetic