Cri-du-chat syndrome: Application of array CGH in diagnostic evaluation
Cri-du-chat syndrome: Application of array CGH
Abstract
The human genome contains many submicroscopic copy number variations which includes deletions, duplications and insertions. Although conventional karyotyping remains an important diagnostic tool in evaluating a dysmorphic patient with mental retardation, molecular diagnostic technology such as array comparative genomic hybridization (aCGH) has proven to be sensitive and reliable in detecting these submicroscopic anomalies. A 3 month-old infant with dysmorphic facies, microcephaly and global developmental delay was referred for genetic evaluation. Preliminary karyotyping which was confounded by the quality of metaphase spread was normal; however, aCGH detected a 30.6Mb deletion from 5p15.33-p13.3. This case illustrates the usefulness of aCGH as an adjunctive investigative tool for detecting chromosomal imbalances.
Keywords :
aCGH; mental retardation; cri-du-chat syndrome,
array comparative genomic hybridization,
Abstrak
Genom manusia mengandungi banyak variasi genetik submikroskopik dari segi salinan nombor; ini termasuk delesi, duplikasi dan insersi. Walaupun analisis kromosom melalui teknik kariotip masih digunakan sebagai ujian utama dalam penyiasatan pesakit dismorfisma yang juga mengalami masalah terencat akal, teknologi molekular seperti hibridasi genomik perbandingan barisan (array comparative genomic hybridisation, aCGH) terbukti sensitif dan boleh dipercayai dalam mengenalpasti variasi genetik submikroskopik ini. Seorang bayi berumur tiga bulan dirujuk kerana masalah dismorfisma, mikrokefali dan rencatan perkembangan global. Ujian kariotip pertama adalah normal. Walaubagaimanapun, keputusan ini adalah berdasarkan kualiti metafasa yang kurang memuaskan. Ujian aCGH telah mengenalpasti delesi bersaiz 30.6Mb pada kromosom 5p15.33-p13.3. Kes ini menunjukkan keberkesanan aCGH sebagai ujian makmal bagi mengenalpasti masalah ketidakseimbangan kromosom.
Kata Kunci :
aCGH; kerencatan akal; sindrom cri-du-chat,
array comparative genomic hybridization,
Correspondance Address
Assoc. Prof. Dr. Zarina Abdul Latif, Department of Paediatrics, Faculty of Medicine, Universiti Kebangsaan Malaysia, Jalan Yaacob Latif, Bandar Tun Razak, 56000 Cheras, Kuala Lumpur.
Tel: 603-91457888. Fax: 603-91456637. Email: zarinaal@ppukm.ukm.my
