A*STAR team finds gene that gives babies smaller heads

SINGAPORE — Scientists at the Agency for Science, Technology and Research (A*STAR) have discovered what causes some babies to be born with smaller heads, a condition called microcephaly, which literally means small head in Latin.

Newborns with the condition are diagnosed at birth and have smaller-than-average head circumferences. Microcephaly could stem from a variety of conditions that cause abnormal growth of the brain during gestation or degenerative processes after birth, all resulting in a small head circumference.

Generally, those with microcephaly have a shorter life expectancy due to reduced brain function, which is often associated with mental retardation.

Together with collaborators from Harvard Medical School, scientists at the Institute of Medical Biology (IMB) and Institute of Molecular and Cell Biology (IMCB) in Singapore discovered that individuals of normal height, but with a very small head size, had mutations in the gene KATNB1 — an essential component in a genetic pathway responsible for central nervous system development in humans and other animals.

The function of KATNB1 was previously unknown in humans. 

Further experiments helped the team’s scientists determine that this gene was crucial for the brain to reach its correct size.

As a result of this finding, sequencing and screening for KATNB1 before birth or at birth may help detect future neurocognitive problems in the general population.

Dr Bruno Reversade, team leader at the IMB, 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.”

Professor Birgit Lane, IMB’s executive director, added: “This is one of a small number of genes that scientists have found to be vital for brain development. The work is therefore an important advance in understanding the human brain.

“The team’s findings provide a new platform from which to look further into whether, and how, this gene can be used for targeted therapeutic applications.”