Definition

What is Preimplantation Genetic Screening?

Preimplantation Genetic Screening (PGS) is a technique used to identify genetic defects in embryos created through in vitro fertilization (IVF) before pregnancy. 
Women who have a history of recurrent pregnancy losses or repeated implantation failures will benefit from PGS because it avoids the transfer of aneuploid embryos which will results in miscarriages and IVF failures.  

The incidence of chromosomal abnormalities

Presently, the rate of birth defect is as high as 5.6%. The infertility rate of women of child-bearing age is about 10~15%, and about 15~20% natural pregnancies suffer from spontaneous abortion (SA) and about 2~8% couples suffer from recurrent spontaneous abortion (RSA). Most of these problems are caused by chromosomal abnormalities.

PGS can

  • PGS can increase clinical pregnancy and live birth rates.
  • PGS can decrease miscarriage rates since only chromosomally normal embryos are transferred.
  • Women who are of advanced maternal age or whose ovarian reserve is limited may choose to bank chromosomally screened blastocysts for the future or use PGS to minimize their risk of miscarriages.
  • PGS can reduce delivery of children with genetic defects.
  • Finally, PGS may increase pregnancy rate for women receiving single embryo transfer.

PGS Increases the Clinical Pregnancy Rate and Reduces Miscarriage Rate Remarkedly

        

Development of PGD/PGS

The first generation of PGD/PGS technology  
PCR and FISH

  • Low throughput, specific chromosome.

The second generation of PGD/PGS technology  
aCGH and SNP array

  • High throughput, high cost.

The third generation of PGD/PGS technology
NGS

  • High throughput, comprehensive.

Principle

  • PGS for Chromosome Aneuploidy Screening

    Comprehensive
    Faster

    Could be the largest NGS-based PGS data set
    Examine all 24 chromosomes including autosomes 1-22 and the sex chromosomes (X, Y)
    Chromosome aneuploidy number and structural abnormalities
    Detect chromosome micro-repeat/micro-deletion of >4Mb in size
    Unsurpassed accuracy, a less than 0.1% false-positive rate
    Automated analysis with a patented bioinformatics analytical software

  • PGS for Mitochondrial Copy Number Analysis

    A new evaluation index for embryos

    Big data based

  • PGS for Mosaic Analysis

    Mosaic embryos indentification

    Innovative bioinformatics algorithm
    > 30% mosaics

The PGS service offered by Jabrehoo has several unique features:

Benefits

  • Accurate: Examine all 24 chromosomes including autosomes 1-22 and the sex chromosomes (X, Y), a less than 0.1% false-positive rate
  • Profession: Automated analysis with a patented bioinformatics analytical software and could be the largest NGS-based PGS data set
  • Flexible: The number of samples have more choice and can meet different clinical needs.
  • Efficient: Testing in 72 hours.

Clinical Process

Process of PGS Testing
 

Target Patients

Target patients for PGS

  • Advanced maternal age (AMA)
  • Women with recurrent miscarriage (RM)
  • Women with recurrent implantation failure (RIF)
  • Severe male factor(SMF)

Case

Common chromosome aneuploidy syndromes

Diseases Location Incidence Remarks
Down syndrome Trisomy 21
(47,XX; 47,XY)
1/750-800 An increased incidence in women of advanced age
Edwards syndrome Trisomy 18
(47,XX; 47,XY)
1/6,000 Most of the fetus miscarry during pregnancy
Patau syndrome Trisomy 13
(47,XX; 47,XY)
1/10,000 95% fetus will die in the uterus
Trisomy X syndrome Trisomy X
(XXX)
1/1,000(girls) Most of the patients do not have obvious clinical manifestations, while only 10% will have a diagnosis
Klinefelter syndrome 47,XXY 1/500-1,000(boys) Symptoms are relatively mild. Miscarry rate is as high as 50%.
XYY syndrome 47,XYY 1/1,000(boys) Not related to advanced maternal age
Turner syndrome 45,X 1/2,500(girls) Miscarry rate is about 15%

Common chromosome micro-repeat/micro-deletion syndromes

Diseases Location Incidence Remarks
Angelman syndrome Chr 15q11.2-q13 1/12,000-25,000 Unable to live independently
Cri du chat syndrome Chr 5p 1/15,000-50,000 More common in women
DiGeorge syndrome Chr 22q11.2 1/4,000-5,000 Some carrier are asymptomatic
Langer-Giedion syndrome Chr 8q23.3-q24.13 Unknown A very rare disease
Miller-Dieker syndrome Chr 17p13.3 1/100,000-300,000 Most patients will die prematurely
Prader-Willi syndrome Chr 15q11.2-q13 1/100,000-300,000 Have a normal lifespan. No treatment is available
Smith-Magenis syndrome Chr 17p11.2 1/25,000-50,000 Many patients are not diagnosed
Williams-Beuren syndrome Chr 7q11.23 1/7,500-2,000 Have a shorter lifespan. No treatment is available
Wolf-Hirschhorn syndrome Chr 4p16.3 1/50,000 More common in women