Hwang Kwei Shuai, Pearson Margaret A, Stankiewicz Pawel, Lennon P Alan, Cooper M Lance, Wu Jessica, Ou Zhishuo, Cai Wei-Wen, Patel Ankita, Cheung Sau Wai
Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA.
Am J Med Genet A. 2005 Aug 15;137(1):88-93. doi: 10.1002/ajmg.a.30858.
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.
分子细胞遗传学能够识别隐匿性染色体重排，这对于常规细胞遗传学分析结果正常的智力发育迟缓及/或畸形个体具有临床诊断价值。我们报告了一名3岁女童，她存在智力发育迟缓、生长发育不足、语言发育迟缓以及畸形特征，包括眼距增宽、睑裂向上倾斜、面中部发育不全和耳向后旋转。G显带分析显示其核型为46,XX,t(3;8)(q26.2;p21.1)mat。然而，她的临床特征提示为18q综合征。亚端粒荧光原位杂交分析显示一条der(18)染色体上有来自17号染色体的易位物质。使用亚端粒BAC和PAC克隆进行的基于阵列的比较基因组杂交（array-CGH）证实了该异常，并将断点精确到18q22.3 - qter和17p13.2 - pter（分别缺失8.5 Mb和重复3.9 Mb）。该病例证明了将常规细胞遗传学与分子染色体分析相结合用于识别细微染色体异常的诊断效用。
