SA study sheds new light on how babies respond to developmental interventions

Genes play a role in whether toddlers will respond to interventions to improve their development.

Scientists are learning the first few years of a child's life can be a good predictor of whether they will have successful life or be condemned to a life of poverty.

Now an international study conducted in South Africa shows that genetics can determine whether an underprivileged baby will respond to interventions to help them.

The study was published in the journal PLOS on Tuesday night.

Chief Executive Officer of Grand Challenges Canada Dr Peter A Singer said: "This is a startling finding that changes the way I think about child development. Why is that important? Because child development is the ladder of social mobility to climb out the hole of inequity for millions of children all over this inequitable world."

The first study was conducted by Stellenbosch Professor Mark Tomlinson between 1999 and 2003 in which caregivers taught about 220 Khayelitsha mothers to communicate and engage with their babies to help them form good bonds‚ a process dubbed "attachment".

Attachment is a psychological measure of a child's bond with its mother and can predict future well being.

Another 220 mothers received no training. Their children were assessed at 18 months and compared with babies whose mothers received training.

The trial was described as only "moderately” successful‚ registering a small improvement.

But researchers recently found 220 of the original children and analysed if they had a short or long form of the SLC6A4 – the serotonin transporter gene‚ which is involved in nerve signalling‚ and which has been linked to anxiety and depression.

The attachment of children with the short form of the gene‚ and whose pregnant mothers were mentored‚ were almost four times more likely to be securely attached to their mothers at 18 months old than children carrying the short form whose mothers did not receive help. The intervention really helped them.

Meanwhile‚ children with the long form of the serotonin transporter gene did equally well regardless of the mentoring or not.

Tomlinson told The Times they didn’t want to genetically screen children as it would be "morally wrong".

But the study showed that intervention that was thought to be only moderately successful actually had a very strong effect on some children.

It may mean many other published studies on intervening in child development that didn’t seem helpful need to be re-examined‚ he explained.

"This raises more questions than answers‚" Tomlinson said. But it showed some children in adverse situations might need more interventions and explained why some might be more resilient‚ he said.

– TMG Digital/The Times