[Clinical and cytogenetic study in a child with de novo chromosome 9 abnormality].

This study aimed to analyze the clinical phenotype of chromosome 9p deletion or duplication and its relationship with karyotype. A patient, female, aged 6 months, visited the hospital due to motor developmental delay. Karyotype analysis identified abnormalities of chromosome 9 short arm, and high-throughput sequencing found 9p24.3-9p23 deletion and 9p23-9p13.1 duplication. Her parents had a normal karyotype. Karyotype analysis combined with high-throughput sequencing is of great significance for improving the efficiency of etiological diagnosis in children with motor developmental delay or multiple congenital deformities and mental retardation.

[Application of DNA Microarray in Genetic Mutation Detection in Patients with Thalassemia].

OBJECTIVE: To perform dried blood spots thalassemia gene detection in patients with positive blood phenotypes by microarray technology, and evaluate its value in clinical detection. METHODS: DNA samples were extracted from dried blood spots of 410 patients. Microarray technology was used to detect 3 deletion and 3 non-deletion types of α-thalassemia and 19 ß-thalassemia point mutations which were common gene mutions in China. RESULTS: There were 357 positive cases in all the 410 tested samples with the positive rate 87.07%, among which 299 cases (72.93%) carried deletion or point mutations of α-thalassemia, 29 cases (7.07%) carried point mutations of ß-thalassemia and 29 cases (7.07%) carried gene mutations of complex αß-thalassemia syndrome. The mutations of α-thalassemia were involved with --SEA heterozygous deletion (177 cases, 59.2%), αCS heterozygote (60 cases, 20.07%) and several other genotypes. The common mutations of ß- thalassemia were involved with ßCD41-42 heterozygote (10 cases, 34.48%) and ßCD17 heterozygote (9 cases, 31.03%). The mutations of complex αß-thalassemia syndrome were mainly involved with --SEA/αα+ßCD17/ßN (7 cases, 24.14%), αCSα/αα + ßCD41-42/ßN (3 cases, 10.34%) and -α4.2/αα + ßCD17/ßN (3 cases, 10.34%). CONCLUSION: The most common genetic mutations are --SEA for α-thalassemia and CD41-42 for ß-thalassemia in Liuzhou, Guangxi Zhuang Autonomous Region. A and ß-thalassemia can be detected at the same time by microarray chip technology in a high throughput manner.