Question

Which of the following cannot be detected in a developing foetus by amniocentesis?

• A. Sex of the foetus
• B. Down syndrome
• C. Cleft lip
• D. Klinefelter syndrome

Answer 1

The correct option is C Cleft lip

Amniocentesis is a prenatal diagnostic technique in which a sample of amniotic fluid is taken from the amniotic sac of the developing foetus to detect the sex and early development of the foetus. That’s why it is also called an amniotic fluid test or AFT. This amniotic fluid test (AFT) is generally performed within 14-20 weeks of the pregnancy, amniocentesis tests for abnormalities in genes or chromosomes to test the presence of certain genetic disorders like anaemia, Down syndrome, Klinefelter syndrome, etc.

Down syndrome is a genetic disorder caused due to an extra copy of the 21st chromosome. It is a case of trisomy (a medical term used for an extra copy of a chromosome ), that causes many physical deformities and abnormal growth.

Klinefelter syndrome is a genetic condition where a baby boy is born with an extra X chromosome. Normally men have XY chromosomes but in this type of genetic disorder, they have XXY instead. That affects physical, mental and intellectual development. The affected individuals may have small penis, enlarged breast tissues, production of little or no sperm, etc.
A cleft lip occurs if the tissues that makes up the lip do not join completely before birth. This leads to an opening or empty space/slit which may even reach to the nose level. It can be diagnosed through imaging techniques such as ultrasounds. Upon confirmation, further chromosomal tests may be done.