In the Andean town of Piñas in southern Ecuador, sisters María Luísa and María del Cisne stand well under average height. Both have Laron syndrome, a rare genetic condition that prevents the body from using its own growth hormone. Around the world, only about 840 people are known to carry the mutation, and a striking number of them live in the same two Ecuadorean provinces.
The syndrome, named after Israeli paediatrician Zvi Laron who identified it 60 years ago, traces its ancestry to a mutation that originated thousands of years ago in Indonesia and travelled westward along merchant routes. In isolated communities where families married within the group over many generations, the mutation concentrated — which is why Ecuador, not the region of its origin, now holds most of the world’s Laron patients.
The curious part for scientists is not the height, but the health. Decades of research have shown that people with Laron syndrome develop far less cancer and diabetes than the general population. The reason lies in the body’s GH–IGF-1 axis: growth hormone stimulates a protein called insulin-like growth factor 1, which drives cell division. Laron patients are resistant to growth hormone, so IGF-1 stays low. Because fewer cells are being told to divide, there are fewer opportunities for the kind of runaway growth that becomes cancer.
Endocrinologist Dr Jaime Guevara, who has studied the community for 40 years, frames the hope plainly: if medicine could replicate, through a drug or a diet, what naturally happens in people with Laron syndrome, it could protect others from cancer without the trade-off of a lifelong growth disorder.
Knowledge takeaway: Laron syndrome blocks the body’s use of growth hormone, keeping IGF-1 levels low; the same low IGF-1 environment appears to reduce cancer and diabetes risk, suggesting that modulating the GH–IGF-1 pathway could one day be a strategy for cancer prevention.