Spoan disease: Rare condition in Brazil town popular for cousin marriage

Many children in a Brazil town lost the ability to walk, so one scientist set about discovering why.

Watch LiveBritish Broadcasting CorporationHomeNewsSportBusinessInnovationCultureArtsTravelEarthAudioVideoLiveHomeNewsIsrael-Gaza WarWar in UkraineUS & CanadaUKUK PoliticsEnglandN. IrelandN. Ireland PoliticsScotlandScotland PoliticsWalesWales PoliticsAfricaAsiaChinaIndiaAustraliaEuropeLatin AmericaMiddle EastIn PicturesBBC InDepthBBC VerifySportBusinessExecutive LoungeTechnology of BusinessFuture of BusinessInnovationTechnologyScience & HealthArtificial IntelligenceAI v the MindCultureFilm & TVMusicArt & DesignStyleBooksEntertainment NewsArtsArts in MotionTravelDestinationsAfricaAntarcticaAsiaAustralia and PacificCaribbean & BermudaCentral AmericaEuropeMiddle EastNorth AmericaSouth AmericaWorld’s TableCulture & ExperiencesAdventuresThe SpeciaListEarthNatural WondersWeather & ScienceClimate SolutionsSustainable BusinessGreen LivingAudioPodcastsRadioAudio FAQsVideoLiveLive NewsLive SportHomeNewsSportBusinessInnovationCultureArtsTravelEarthAudioVideoLiveWeatherNewslettersWatch LiveThe rare disease in a remote town where 'almost everyone is a cousin'3 days agoShareSaveGiulia Granchi and Vitor TavaresBBC Brasil reporters sent to Serrinha dos PintosShareSaveMariana Castiñeiras/Caroline SouzaAffected families in Serrinha dos Pintos lived without a diagnosis until geneticist Silvana Santos arrived Before Silvana Santos arrived in the little town of Serrinha dos Pintos more than 20 years ago, residents had no idea why so many local children had lost the ability to walk.

The remote town in north-eastern Brazil is home to fewer than 5,000 people, and is where biologist and geneticist Santos identified and named a previously unknown condition: Spoan syndrome.

Caused by a genetic mutation, the syndrome affects the nervous system, gradually weakening the body. It only appears when the altered gene is inherited from both parents.

Santos's research marked the first time the disease had been described anywhere in the world. For this and later work, she was named one of the BBC's 100 most influential women in 2024.

Before Santos arrived, families had no explanation for the illness affecting their children. Today, residents talk confidently about Spoan and genetics.