A few years ago a scientific study showed beyond doubt that adolescent idiopathic scoliosis (AIS) – the non-congenital form of scoliosis – is part inherited from the parents. Several studies have been published on this, see here and here for a recent one.
Several genes have been proven to influence the development of scoliosis, however, for the first time a single gene has been determined across a single family influencing scoliosis. AIS seems to be a complex disorder caused by the interplay of many genes as well as environmental factors. But at least AIS is no longer totally idiopathic – meaning with unknown cause.
While some genes may contribute to causing scoliosis, others may play a role in determining the magnitude of the spinal curves.
To complicate matters even further, there seems to be two different ways of inheriting scoliosis, either sporadic where it occurs in a family without any previous cases of the condition (perhaps a recessive form) or a familial form (perhaps dominant). However, in any case it is clear that having a close relative with AIS increases a child’s risk of developing it.
I have been unable to find any estimates of the chance of passing on scoliosis to your child – but it seems to be between 5-25%. Does anyone know? As AIS is more prevalent in girls, having a daughter would increase the risk. Vice versa if noone else in your family has it, the chance should be lower.
The increasing genetic basis for scoliosis will longer term make it possible to develop better genetic tests for determining the likelihood of a child developing scoliosis and even longer term potentially gene therapy to reduce or cure scoliosis.
Update December 2016: a new study has been published, see here. It concerns the discovery of a gene (POC5) that plays a role in directly causing scoliosis. It seems to be the first time a single gene has been pinpointed to be a cause of scoliosis. The research team is sure that there are many other genes that play a role as well as scoliosis is a complex disease. The gene seems to be dominant and was discovered both in families where many had scoliosis and in families where just a single person had scoliosis. The gene has to do with the development of a certain protein that is strongly expressed in the brain, so the research team suspects that there is a link between the brain development and idiopathic scoliosis.