SINGAPORE - Scientists from the Agency for Science, Technology and Research (A*Star) have discovered what causes babies to be born with smaller heads.

People who suffer from this rare condition called microcephaly generally have a shorter life expectancy because of reduced brain function. Babies are diagnosed at birth by measuring their head circumference.

Singapore-based scientists, who worked with Harvard Medical School, have established that microcephaly is due to mutations in the KATNB1 gene. It is an important component in a genetic pathway responsible for central nervous system development in humans and other animals.

Their discovery may provide a new platform for targeted treatment, said Professor Birgit Lane, head of A*Star's Institute of Medical Biology. Screening for this gene in foetuses can also be a helpful indicator of future neurocognitive development.

Research team leader, Prof Bruno Reversade, said: "We will continue to search for other genes important for brain development as they may unlock some of the secrets explaining how we, humans, have evolved such cognitive abilities."

His team's work on KATNB1 was published in Neuron, a neuroscience journal, earlier in December.