Genetic Screening

Genetic Screening

Overview

  • Genetic screening is a type of medical test which identifies changes in chromosomes, genes, or proteins.
  • This tool is instrumental in determining genetic disorders, assessing changes in genes, and even predicting the chances of diseases in unborn babies.
  • It can be applied in various scenarios such as prenatal, newborn screening, carrier screening, and even in predicting cases of breast or ovarian cancers.

Methods

  • The process involves a variety of techniques including karyotyping, biochemical genetic tests and molecular genetic tests.
  • Karyotyping is a technique that allows for the visual assessment of an individual’s set of chromosomes.
  • Biochemical genetic tests evaluate the activity level of proteins; abnormal activity can indicate changes in the DNA that result in a genetic disorder.
  • Molecular genetic tests such as Polymerase Chain Reaction (PCR) or gene sequencing are used to study single genes or short lengths of DNA.

Applications

  • Prenatal screening helps detect genetic disorders in a fetus such as Down syndrome, Edward’s syndrome and Patau’s syndrome.
  • Newborn screening is used just after birth to identify genetic disorders that can be treated early in life.
  • Western countries routinely screen newborn babies for phenylketonuria and cystic fibrosis among many other conditions.
  • Carrier screening is done on prospective parents to determine the likelihood of their offspring inheriting genetic disorders.

Ethical and Social Considerations

  • With the potential benefits, genetic screening also raises ethical issues such as confidentiality, informed consent and potential psychological impact.
  • False positives can cause unnecessary stress and anxiety, while true positives might lead to difficult decisions about treatment or management.
  • There are also concerns about genetic discrimination and stigmatisation.

Recent Advances and Future Perspective

  • Scientists are developing more efficient methods of genetic screening, for example, non-invasive prenatal testing (NIPT), which requires only a sample of maternal blood to screen for certain conditions in an unborn baby.
  • Genetic screening is anticipated to play a more significant role in personalised medicine, where treatment is tailored to an individual’s unique genetic make-up.