Genome-sequencing screening for babies unlocks blueprint of health

General Studies Paper 2

CONTEXT

• Newborn screening programmes are now in vogue in different countries, and have been deployed in India as well. They are based on the fact that an early diagnosis could allow use of effective treatments and save an infant from death or disability.

ABOUT

• There are 6,000 or so genetic diseases, of which around 3,500 diseases have been documented, and a much smaller number have had their molecular and/or genetic defects mapped.
• A significant number of diseases in the population are also treatable but are nevertheless prevalent.
• Newborn screening programmes now in vogue in different countries, and which have been deployed in some states in India as well, are based on the fact that an early diagnosis could allow us to use effective treatments and save an infant from death or disability.
• Then again, in many cases, they lose the window of opportunity because standard newborn-screening programmes are limited on the menu of genetic tests they cover.
• Thanks to recent advances, genomic-sequencing is now available, accessible, and in many ways more affordable.
• It also offers a much better coverage of genetic diseases to screen for.
• Importantly, this could help healthcare workers make a fast and effective diagnosis, helped by the fact that sequencing is also a ‘single’ test, versus the multitude of tests performed as part of routine newborn- screening.

 IT’S IMPORTANCE

• The rarity of many genetic diseases, the narrow window of opportunity, the long diagnostic paths, and the unfortunate deaths of ill babies makes it very difficult to document and understand these diseases.
• However, population-scale genome-sequencing efforts have provided insights into the prevalence of many of these diseases in an unbiased manner.
• Discoveries in the past three decades have also allowed a small but significant number of diseases to be treated or managed effectively.
• This in turn opened up a newer opportunity: to diagnose and treat genetic diseases through genomic- sequencing in newborn babies, especially sick ones.

SCREENING HEALTHY BABIES

• The benefits of sequencing may not just be limited to babies who are unwell.
• One recent study conducted by the project, and published in the American Journal of Human Genetics, evaluated the sequences of 127 apparently healthy and 32 sick infants.
• It found that just over 10% of infants had an unanticipated risk of genetic diseases.
• When these infants were followed up for three to five years, sequences revealed the causes of disease in three infants; in the remaining 14, a better picture of the risk made way for better medical surveillance.
• The sequencing also warranted additional at-risk family members of 13 infants to have their genes sequenced. Three of them benefited from subsequent surgeries.

ETHICS AND HOPE

• Newborn whole genome sequencing presents multiple ethical challenges.
• Such as the issue of disclosing and managing incidental and secondary findings raises concerns about privacy and the psychological impact on families.
• The equitable distribution of benefits and burdens associated with accessing and utilising this technology also invoke issues of justice and fairness .

WAY FORWARD

• As the vast potential of rapid newborn whole-genome sequencing unfolds, we stand at a crossroads of hope and introspection.
• There is no doubt that this technology will help clinicians with the means to detect rare genetic disorders, anticipate susceptibility to disease, and give them the evidence required to prescribe better treatments and shape a healthier future.
• Yet we must also tread carefully, considering the delicate balance between benefits and harm.