PRENATAL DIAGNOSIS MOLECULAR KARYOTYPING: USING THE CGH ARRAY ON FETAL DNA (MICROARRAY)
WHAT IS A CGH-ARRAY ANALYSIS?
The CGH – ARRAY analysis is a technique that uses a 2nd level diagnostic in-depth to integrate with prenatal cytogenetic analysis. It allows you to study the unborn child’s chromosomes more accurately.
The integration of these two techniques allows you to increase significantly the possibilities of determining the causes of the disease found in the unborn child and possibly allows you to define, more accurately, the risk of recurrence in the future.
HOW IS IT PERFORMED?
The survey can be performed on DNA extracted directly from fetal cells obtained with the non-cultivated tissue samples during chorionic villus sampling and the amniocentesis procedure.
Using a molecular technique that doesn’t require cultivation, it is possible to obtain an in-depth chromosomal analysis in just 3 days, with clear advantages for patients such as reducing the anxiety of the mother and, in the case of a pathological result, the immediate management of potential therapeutic treatments.
WHEN DO YOU PERFORM IT?
The examination can be performed on chorionic villi or amniotic fluid. It follows that the preferred gestational age to be taken into account should be that of chorionic villus sampling (from the 10th week) or amniocentesis (from the 16th week).
WHEN SHOULD IT BE USED?
The array-CGH technique is useful to deepen the prenatal diagnosis if you are having:
Developmental defects detected by fetal ultrasound, where the traditional karyotype was normal;
Fetus with chromosomal abnormalities (unbalanced rearrangements, rearrangements apparently balanced de novo and mosomal markers) identified through prenatal cytogenetic analysis;
Miscarriages and therapeutic abortions
WHICH DISEASES CAN BE DETECTED BY USING THE CGH-ARRAY?
There are about 80 detectable diseases using the CHG-Array diagnostic method. Click on the image side to see the detailed list.
WHAT ARE THE POSSIBLE DIAGNOSTIC RESULTS?
An international validation performed on more than 15,000 cases, in which the two analyzes were performed in parallel, showed that this technique has proven to be particularly reliable in identifying several chromosomal microalteration syndromes that had not been detected during traditional analysis.
The CGH Array does not detect balanced chromosomal alterations, which have no clinical significance, neither pathologic nor the mosaics whose percentage of base line is lower than 8 to 10% of total cells, the frequency of which is extremely rare and also difficult to display with the cytogenetic examination.
WHAT ARE THE RISKS RELATED TO TAKING THIS EXAMINATION?
No additional risk as the examination is performed on the material taken with Chorionic Villus Sampling or Amniocentesis.