ABSTRACT
<p><b>OBJECTIVE</b>To ascertain the karyotype of a girl with moderate mental retardation and growth retardation, perform correlation analysis between chromosomal variation and phenotype, and investigate the application and superiority of array-based comparative genomic hybridization (array-CGH) in clinical cytogenetic diagnosis.</p><p><b>METHODS</b>G-banded chromosome analysis, array-CGH, fluorescence in situ hybridization (FISH) and real-time quantitative PCR (RQ-PCR) were used to ascertain the karyotype of the patient and her relatives.</p><p><b>RESULTS</b>G-banding analysis of the patient showed a derivative chromosome 10 with an extra fragment on its long arm terminal, both her father and grandmother had an apparently balanced translocation t(4;10)(q25;q26). Array-CGH revealed that the breakpoint on chromosome 4 was located at 4q26. In addition, a microdeletion of about 0.54 Mb del(10)(q26.3) was identified from the patient. FISH and RQ-PCR confirmed that the del(10)(q26.3) was also present in both her father and grandmother.</p><p><b>CONCLUSION</b>No recognizable phenotype was associated with del(10)(q26.3). The abnormal phenotypes presented in the patient may be ascribed to the 4q26-q35.2 triplication. Further more, compared with conventional cytogenetic analysis, array-CGH is of high resolution and high accuracy.</p>
Subject(s)
Child, Preschool , Female , Humans , Male , Chromosome Deletion , Chromosomes, Human, Pair 10 , Genetics , Chromosomes, Human, Pair 4 , Genetics , Comparative Genomic Hybridization , Cytogenetic Analysis , In Situ Hybridization, Fluorescence , Intellectual Disability , Genetics , Karyotyping , Phenotype , Polymerase Chain Reaction , Trisomy , GeneticsABSTRACT
<p><b>OBJECTIVE</b>To measure the feasibility of application of comparative genomic hybridization technique in the prenatal diagnosis of fetus with mandibulofacial dysostosis.</p><p><b>METHODS</b>A pregnant woman having a fetus with mandibulofacial dysostosis diagnosed by prenatal ultrasound test was selected. The amniotic fluid and blood of the pregnant and blood of her husband were collected and conventional cytogenetic analysis was performed. The whole genome was scanned by array comparative genomic hybridization assay (array-CGH). Reverse transcription fluorescence quantitative PCR (RT-qPCR) analysis was used to verify the result of array-CGH.</p><p><b>RESULTS</b>No abnormality was found in conventional cytogenetic analysis while a duplicated region in 1p36.33 was detected by array-CGH assay. The region spans 722 kb and contains two genes, VWA1 and PYGO2, which play roles in the development of cartilage. The result of array-CGH was confirmed by the RT-qPCR assay. The diagnosis of mandibulofacial dysostosis was confirmed after birth.</p><p><b>CONCLUSION</b>Author diagnosed a fetus with mandibulofacial dysostosis by array-CGH assay and found two candidate genes related to the development of craniofacial bone: VWA1 and PYGO2.</p>