Objective To further explore the relationship between increasing genetic material and clinical manifestation of partial trisomy 5p .Methods G‐banding karyotypes of peripheral blood lymphocytes in the patient and his parents ,and at the same time to summary the partial trisomy 5p clinical performance .Results patient ,46 ,XX ,der(6)t(5 ;6)(p13;q25) mat ;partial trisomy for 5p13→pter resulting from the balanced translocation of the mother .Mother:46 ,XX ,t(5;6)(p13 ;q25);carrier of a balanced 5/6 translocation .Father :46 ,XY .Conclusion The phenotype of trisomy 5p may be associated with express and function of gene at spe‐cial chromosome region .

Objective To valuate the applicability of multiplex ligation‐dependent probe amplication (MLPA ) for detection of chromosomal unbalance .Methods Aneuploid and subtelomeric MLPA technology were used to analyze 6 samples with chromosom‐al unbalances ,confirmed by karyotype analysis .Results All samples were identified to have abnormal signal of corresponding probes .The extent of unbalances contained subtelomeric region .Conclusion MLPA technology could have important role in diag‐nosis of chromosomal unbalance ,which could complement conventional karyotype analysis .

OBJECTIVETo assess the value of noninvasive fetal trisomy testing based on massively parallel sequencing for the detection of chromosomal deletions and duplications.

METHODSPeripheral venous blood was taken from pregnant women with a high risk. Free fetal DNA in maternal plasma was used for library construction and subjected to massively parallel sequencing. Positive results were validated by traditional karyotype analysis or array-CGH. Phenotype of the fetus was observed through patholoical evaluation.

RESULTSThirteen out of 629 cases were suspected to harbor chromosomal aberrations, which included 9 aneuploid cases and 4 structural abnormalities. The latter included one case with dup (18q) (14.35 Mb), del (18q) (21.34 Mb), one with dup (3q) (35 Mb) and two with dup (7q) (7.0 Mb). Among these, dup (18q ) (14.35 Mb), del (18q) (21.34 Mb) and dup (3q) (35 Mb) were confirmed by karyotype analysis and patholoical evaluation. However, the two cases with dup (7q) were validated by karyotype analysis and array-CGH as false positives. The phenotype with the fetus also presented as normal.

CONCLUSIONThe introduction of maternal plasma sequencing for prenatal testing could dramatically improve the efficiency for detecting large, partial (> 10 Mb) chromosomal deletions and duplications.

Adult ; Chromosome Deletion ; Chromosome Duplication ; Comparative Genomic Hybridization ; Female ; Fetal Diseases ; diagnosis ; genetics ; Genotype ; Humans ; Pregnancy ; Prenatal Diagnosis ; methods ; Reproducibility of Results ; Sensitivity and Specificity ; Sequence Analysis, DNA ; methods ; Trisomy