[Phenotypic and genetic analysis of a sibpair with partial deletion of SATB2 gene caused by 2q33.1 microdeletion].

OBJECTIVE: To analyze the genotype and phenotype of a sibpair with partial deletion of SATB2 gene caused by 2q33.1 microdeletion. METHODS: Both children have featured mental retardation and development delay, and were subjected to karyotyping, single nucleotide microarray (SNP array) and real-time fluorescence quantitative PCR analysis. Karyotyping and SNP Array analysis were also carried out on their parents to verify the origin of mutation. RESULTS: Both sibs had a normal karyotype. SNP array showed that sib 1 had arr[hg19]2q33.1(200 192 328 - 200 197 269)×1 (4.9 kb), 2q35 (218 105 663 - 218 816 675)×3 (711 kb), while sib 2 had arr[hg19]2q33.1(200 192 328 - 200 197 269)×1 (4.9 kb), 2q35 (218 105 663-218 810 908)×3 (705.2 kb). The deletion has partially overlapped with that of 2q33.1 microdeletion syndrome and involved part of the SATB2 gene. The result of real-time fluorescence quantitative PCR assay was consistent with that of SNP assay. The duplication has originated from their father and has not been associated with any disease phenotypen. CONCLUSION: Both sibs have carried partial deletion of SATB2 gene and had similar clinical phenotypes. Haploinsufficiency of such gene probably underlies the clinical manifestations in both patients.

[Application of BACs-on-Beads and karyotyping for the prenatal diagnosis of 1371 pregnant women with a high risk].

OBJECTIVE: To assess the value of combined BACs-on-BeadsTM (BoBs) and chromosomal karyotyping for the diagnosis of women with high-risk pregnancy. METHODS: For 1371 women with singleton pregnancy and various indications for prenatal diagnosis, karyotyping and BoBs were simultaneously applied on their amnionic fluid samples. RESULTS: In total 23 cases of trisomy 21, 11 cases of trisomy 18, 5 cases of sex chromosome aneuploidies, 6 cases of microdeletions/microduplications, 2 cases of chimeric chromosomes and 1 case of structural chromosomal abnormality were detected by the BoBs assay, among which the 6 microdeletions/microduplications were not detected by karyotyping. Karyotyping analysis has identified an extra yield of 19 chromosomal abnormalities and 34 chromosomal polymorphisms. CONCLUSION: Combined use of BoBs and chromosomal karyotyping can improve the detection rate of fetal chromosomal abnormalities including microdeletions/microduplications, which should find a wider use in the clinics.