PGD

PGD

PGD

  • It is a subfield of clinical genetics and gynaecology that exemplifies the effective integration of theoretical and clinical medicine milestones in its history include development of cytogenetics, Molecular genetics.

Molecular cytogenetic method & advances in USG

  • Prenatal diagnosis strictly comprises all diagnostic modalities aimed at gaining information about the embryo or fetus. In narrower usage it refers to prenatal identification of genetically determined disease and their disposition.

Indications

    • Advanced Maternal Age
    • Known genetic disorder in family
    • Advanced Maternal Age

Genetic dis. Divided into 3 groups

    • Chromosomal Abnormalities
    • Single Gene Disorder
    • Polygentic or Multifactorial Dis.

Invasive Methods

    • CVS (b/w 11th&12th w/c)
    • Aminiocentesis (15th & 17th w/c)
    • Placental biopsy
    • Cordocentesis (16th – 20th w/c)

Non invasive

    • USG+Biochemical marker
    • Known genetic disorder in family
    • Advanced Maternal Age

Its applications are:

    • Detection or exclusion of a specific unbalanced chromosome translocation, where on parent carries a robertsonian or reciprocal translcation.
    • Tection or exclusion of a particular mutation in presence of ed risk of monogentically inherited dis.
    • Polar body biopsy can be used when the woman carries a balanced translocation or the predisposition to monogenerically inherited dis.

Pre implementation Diagnosis (PID)

  • In contrast to PGD, PID is carried out on embryonic cells prior to establishment of pregnancy where one of the blastomeres from 8 cell stage is removed for molecular cytogenetic analysis.