How these twins' rare growth disorder could provide the key to preventing cancer

Key developments are emerging from the global stage. How these twins' rare growth disorder could provide the key to preventing cancerImage source, JORGE PEREZ / BBCImage caption, Sisters María Luisa and María del Cisne say sharing their experiences helps them cope with their challengesByAlejandro Millán Valencia, News Mundo and Sarah Bell, Global Health Published18 July 2026, 00:24 BSTNestled in southern Ecuador's network of Andes mountains is the town of Piñas, whose 8,000 inhabitants live in houses scattered across a valley. This remote town is home to an unusually high number of people living with Laron syndrome, a rare genetic condition that prevents the body from growing taller than 1. María Luísa Romero and her twin sister, María del Cisne, both have the condition but they say being there for each other has helped them.

"We're always strong, we pool our strength and one defends the other," María Luísa explains as she sits on a sofa next to her sister. Living with Laron syndrome can be challenging, the sisters say. But researchers believe it may provide an unexpected advantage - the incidence of diseases such as cancer and diabetes among Laron patients is lower than in the general population.

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They hope that studying this could lead to the development of treatments to prevent cancer. "The idea is to be able to replicate, through a drug or a diet, what happens in people with Laron syndrome, in other people without the syndrome," says endocrinologist Dr Jaime Guevara, who has been studying it for 40 years. "It would be a great contribution from this wonderful community to the world.

"Image source, JORGE PEREZ / BBCImage caption, Globally, 840 people are known to have the condition, with the majority living in southern EcuadorThose who have Laron syndrome, also known as growth hormone insensitivity, are unable to use the growth hormone that their body makes. The genetic mutation is named after paediatrician Zvi Laron, who identified it while treating patients in Israel, 60 years ago. Globally, 840 people are known to have the condition, with the majority living in the southern Ecuadorean provinces of El Oro and Loja.

Originating thousands of years ago in Indonesia, it moved west as its carriers travelled along merchant routes, Prof Laron believes. He says Sephardic Jews with the mutation later migrated to different continents and some travelled to the Americas. According to Prof Laron, they settled in isolated areas and after generations of marrying within their group, a particularly high incidence is now found in Ecuador.

Living near others who have the syndrome has helped with the challenges, the twins say, as it means they know they are not alone. "We can tell each other about the things that happen to us, the good and the bad, because we definitely share many of the challenges we have to face every day," explains María del Cisne.

The story has become one of the most prominent items on the global agenda.