Preimplantation Genetic Testing

Tools & Facilities

Ahmad Mustafa MetwalleyMSc, Molecular PathologyViafet- Dubai

PGT, is a technique used to identify genetic defectsin embryos .

Known as "embryo screening,"ART procedure followed by embryos cells isolation to be tested.To screen chromosomal or genetic abnormalities .

Introduction of PGT in IVF revolutionized ARTTo prevention of transmission of hereditary diseases and chromosomal abnormalities

Chromosomes• PGS: Preimplantation Genetic Screening

• CCS: Comprehensive Chromosomal Screening

Genes• PGD: Preimplantation Genetic Diagnosis

• PGH: Preimplantation Genetic Haplotyping

Preventing Chromosomal Abnormalities

FISH)) A- Simple

B- Full Screening (CCS)

A- FISH : Fluorescence In Situ Hybridization - 13 ,18 ,21 ,X and Y

- Sex differentiation with normal embryos - Balanced chromosomal translocations

- Increases IVF output to :

Number of cases/Sac with Heart

≤36 >37

FISH day 3 34 / 67 = 51% 17 / 45 = 37%

FISH day 5 42 / 62 = 68% 20 / 34 = 59%

B- CCS: Comprehensive Chromosomal Screening - 24 chromosomes - CGH-Array, Ion Torrent and NGS - Identifying micro-deletions and translocations - Yang et al., 2012: RCT, CGH with SET incased IVF:

Number of cases/Sac with Heart

PGS - CCS No PGS

Array at day 5 39 / 55 = 71% 22 / 48 = 46%

Dose PGS helps recurrent abortion Patients?

Poor quality eggs associated with advanced maternal age is

associated with chromosomal abnormalities

Somatic chromosomal abnormalities are the main cause of

recurrent mischarge, recurrent failure.

Micro deletion or translocations can be screened simply by PGS

Sever male factor indicated for PGS

Preventing Hereditary Disease

Known also as single gene disorders

• Autosomal Recessive Disorders

• Autosomal Dominant Disorders

• X-linked Recessive Disorders

• Cancer Hereditary Disease

Ataxia Telangiectasia Sickle cell

Infantile Seizures Thalassemia

Breast Cancer Mediterranean Fever

Cholestasis G6PD

Galactosemia Hemophilia

Gaucher Disease DMD

Hunter Disease Cystic Fibrosis

Immunodeficiency Spinal Muscular Atrophy

Polycystic Kidney Metabolic disorders

Wolmann Disease Fragile X syndrome

Primary Hyperoxaluria Albinism

PGD-PCR or PGD-NGS is performed to differentiate affected,

carrier or healthy embryo for transfer from abnormally

genotyped parents.

Paternal mutations are required for screening prior to cycle

....Step to avoid abnormality inheritanceAs well as Gender Selection……

Also, HLA compatibility testing….

• Bone Marrow transplantation

• Stem cells utilities

• Organs transplantation

Gender Selection……

Gender Selection……

• provides All PGT investigations

within 48 hours between Day3 biopsy and Day5 prepared for ET.

• provides whole case management not single embryos.

• unsuccessful embryos assessment is prepared for retesting.

• ExactCCS and Luminscent are unique to give highest accuracy

and shortest TAT.

• Also, Non Invasive prenatal testing

NIPT, Non Invasive Prenatal Testing….

• Amniocentesis with accepted risk of infection or abortion

• CVS is more aggressive with increased risks

• Triple marker or Double marker are accepted but not promising

• Re-aspiration or resampling is expected

• Advanced gestational weeks are problematic

• NIPT is only Maternal blood at Week 11.

• Result within 10 days for 24 chromosomes with 100 % accuracy