Preimplantation Genetic Diagnosis

Preimplantation Genetic Diagnosis

Genetic diseases are considered to be a major problem. Concentrated efforts have been done by scientists to solve the problem. We will mention a few of the steps taken.

Pre-implantation diagnosis by embryo biopsy:

This is done by taking one or more cells from the embryo. Then, scientists try their best to take as many cells as possible to reach a diagnosis or identify a disease. The best time to do this is after the division of the fertilized egg by IVF, until it reaches the stage of 8 cells. That usually occurs on Day 3 after fertilization. The lab technician creates a hole in the embryo wall by using a very thin microscopic needle or chemical substance, or laser. Then, one cell will be taken without causing damage to the embryo by taking the cells that have no effect on the embryo (nonessential cells) in an advanced stage of the embryo's development (the blastocyst stage), and after that, the diagnosis is done in 2 ways:

2. FISH (fluorescence in situ hybridization):

In this technique, the normal embryos can be selected to be transferred to the uterus as in the case of IVF. It should be taken in to consideration to select the best time to take the biopsy from the embryo and to avoid occurrence of damage to the embryo. In that way, we can achieve the best results in diagnosis which will lead to a healthy, successful pregnancy.
 

embryo biopsy
embryo biopsy
embryo biopsy
embryo biopsy
embryo biopsy
embryo biopsy
embryo biopsy
embryo biopsy
study of embryo biopsy
study of embryo biopsy
study of embryo biopsy
study of embryo biopsy

embryo biopsy

FISH-fluorescence in situ hybridizationembryo
 
 

1. Genetic diagnosis of pre-implantation embryo:

This technique is used to diagnose the inherited diseases and has been developed recently, by using a special test called PCR (Polymerase Chain Reaction) and the number of human genetic diseases that can be diagnosed is increased. We hope, in the future, scientists will be able to diagnose all the genetic diseases in that way. This technique is useful for couples that may have a child who is effected with an inherited disease. In that way, only the normal embryos can be transferred to the uterus. This is much better than the occurrence of a pregnancy than the diagnosis of a genetic disease by Amniocentesis (taking sample of the amniotic fluid), or by Chorionic villous sampling.
 

Gene disorders transmittable to the offspring, which can be analysed by genetic diagnosis after oocyte and embryo biopsy.

Achondroplasia

Central core disease

Agammaglobulinemia

Gaucer’s disease

Sickle-cell anemia

Huntington’s disease

Fanconi’s anemia

Alport’s disease

Spinal/bulbar muscular atrophy

Tay-Sachs’ disease

Alpha1- antitrypsin deficiency

MELAS

Long chain hydroxyacyl CoA dehydrogenase deficiency

X-linked myotubular myopathy

Ornithine transcarbamilase deficiency

Neurofibromatosis I and II

Deficiency of the mitochondrial trifunctional protein

Multiple endocrine neoplasia type II

Multiple epiphyseal dysplasia

Osteogenesis imperfecta I and IV

Myotonic dystrophy

Familial adenomatous polyposis coli

Becker’s muscular dystrophy

Rhetinitis pigmentosa

Duchenne’s muscular dystrophy

Rhesus (Rh D)

Haemofilia A and B

Tuberous sclerosis

Epidermolysis bullosa

Crouzon’s syndrome

Exclusion HD

Di George’s syndrome

FAP-Gardner

Hunter’s syndrome MPS II

Phenylketonuria

Lesch-Nyhan’s syndrome

Cistic fibrosis

Marfan’s syndrome

X-linked hydrocephalus

Digital oro-facial-syndrome type 1

Incontinentia pigmenti

Stickler’s syndrome

Hyperinsulinemic hypoglycemia PHH1

Fragile X syndrome

Early onset Alzheimer’s disease

Wiskott-Aldrich syndrome

Charcot-Marie-Tooth’s disease 1 and 2A

Thalassemia

List of some of the genetic diseases that can be diagnosed by PGD

 

2. FISH (fluorescence in situ hybridization):

Normal embryos can be selected to be transferred to the uterus, as in the case of IVF. It should be taken in to consideration to select the best time to take the biopsy from the embryo, and to avoid the occurrence of damage to the embryo. We can then hope for the best results in diagnosis, leading to a healthy and successful pregnancy.