NIPT Frequently asked questions

Standard NIPT

The main purpose of NIPT is to screen for three common chromosome conditions:

  • Down syndrome (trisomy of chromosome 21)
  • Edwards syndrome (trisomy of chromosome 18)
  • Patau syndrome (trisomy of chromosome 13)

These conditions are caused by the presence of three copies of a particular chromosome (“trisomy”) in every cell of the baby’s body rather than the usual two copies. Each of these conditions causes moderate to profound intellectual disability and is associated with major congenital malformations. The links above provide more information about each syndrome. The chance of a developing baby having one of these syndromes increases with the age of the mother; your doctor can provide you with advice about this.

Assessment for these trisomies is the most accurate NIPT.

Standard NIPT with optional assessment of sex chromosomes

NIPT can also screen for abnormal numbers of sex chromosomes. Males usually have an X and a Y chromosome; females have two X chromosomes. On request from your doctor, NIPT can screen for the presence of more or less than two sex chromosomes for no additional charge. This includes screening for:

  • Turner syndrome (having only one sex chromosome, an X)
  • Klinefelter syndrome (having three sex chromosomes, two Xs and a Y)

These sex chromosome conditions are usually clinically milder than the common trisomies.

NIPT can also detect other abnormalities in the number of sex chromosomes (XXX and XYY) that have little impact on a person’s growth and development.

The links provide more information.

As a separate option, NIPT can also screen for the presence of DNA from a Y chromosome (the male chromosome), indicating the sex of the developing baby. Note that the result of screening the sex chromosomes may indicate the sex of the developing baby, regardless of whether screening for the fetal sex is selected. In a twin pregnancy, the presence of DNA from a Y chromosome is interpreted as there being one or two male fetuses.

Assessment of sex chromosomes by NIPT is very accurate, but not as accurate as standard NIPT.

Standard NIPT with optional genome-wide NIPT

NIPT can also screen for two other types of chromosome abnormality:

  • Gain or loss of a segment of a chromosome; these changes, if confirmed, are often associated with fetal abnormalities
  • A mixture of chromosomally normal and abnormal cells; this abnormality is often confined to the placenta and can interfere with normal fetal growth.

Please note that the NIPT provided by Sonic Genetics is a highly accurate screen for specific conditions. It is not a screen for every possible condition that a developing fetus may have. NIPT is just one of the investigations that your doctor may recommend for you before or during your pregnancy.

This post was last modified on Tháng mười một 20, 2024 4:31 chiều