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

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."She gave us a diagnosis we never had. After the research, help came: people, funding, wheelchairs," says Marquinhos, one of the patients.
Serrinha dos Pintos: a world of its own
Where Santos is from in São Paulo, Brazil's largest and wealthiest city, many of her neighbours were members of the same extended family originally from Serrinha. Many of them were cousins of varying degrees, married to each other.They told Santos that many of people in their hometown couldn't walk, but that no one knew why.One of the neighbours' daughters, Zirlândia, suffered from a debilitating condition: as a child, her eyes moved involuntarily and over time, she lost strength in her limbs and needed to use a wheelchair, requiring help with even the simplest tasks.Years of investigation would lead Santos and a research team to identify these as symptoms of Spoan syndrome.They would go on to find 82 other cases worldwide.
At the invitation of her neighbours, Santos visited Serrinha on holiday. She describes her arrival as stepping into "a world of its own" - not just because of the lush scenery and mountain views, but also due to what seemed to be a notable social coincidence.The more she walked and spoke with locals, the more surprised she was at how common marriages between cousins were.Serrinha's geographical isolation and little inward migration mean that many of the population are related, making marriage between cousins far more likely and more socially acceptable.Worldwide, marriages between relatives were estimated at around 10% in the early 2010s. More recent data shows the rate varies widely, from over 50% in countries like Pakistan, to 1-4% in Brazil and less than 1% in the US and Russia. Most children born to pairs of cousins are healthy, experts say.But these marriages do face a higher risk of a harmful genetic mutation being passed down through the family."If a couple is unrelated, the chance of having a child with a rare genetic disorder or disability is about 2–3%. For cousins, the risk rises to 5–6% per pregnancy," explains geneticist Luzivan Costa Reis from Brazil's Federal University of Rio Grande do Sul.A 2010 study led by Santos showed that more than 30% of couples in Serrinha were related, and a third of them had at least one child with a disability.
Long road to diagnosis
Santos set out to find a diagnosis for the people of Serrinha and she began planning a detailed genetic study, requiring multiple trips and eventually leading to her relocating to the region.She drove the 2,000km to and from São Paulo many times in the early years of her research. She collected DNA samples door-to-door, chatting to locals over coffee and gathering family stories, all the while trying to locate the mutation causing the disease.What was supposed to be three months of fieldwork turned into years of dedication.It all led to the publication in 2005 of the team's study revealing the existence of Spoan in the Brazilian hinterland.Santos's team found that the mutation involves the loss of a small fragment of a chromosome, which causes a gene to overproduce a key protein in brain cells.
"They said it came from Maximiano, a womaniser in our family," recalls farmer Lolô, whose daughter Rejane has Spoan.Lolô, now 83, married his cousin and never left Serrinha. He still tends cattle and relies on family to care for Rejane, who struggles with daily tasks.But the genetic mutation behind Spoan is far older than the legend of Old Maximiano: it likely arrived more than 500 years ago with early European settlers in the north-east of Brazil."Sequencing studies show strong European ancestry in patients, supporting records of Portuguese, Dutch, and Sephardic Jewish presence in the region," says Santos.The theory gained strength after two Spoan cases were found in Egypt, and further studies showed that the Egyptian cases also shared European ancestry, pointing to a common origin in the Iberian Peninsula."It likely came with related Sephardic Jews or Moors fleeing the Inquisition," says Santos. She believes more cases may exist globally, especially in Portugal.
Understanding the risks
Although there's been little progress toward a cure, tracking patients has brought some change. Rejane recalls how people used to be called "cripples". Now, they're simply said to have Spoan.Wheelchairs brought not just independence, but also helped prevent deformities - in the past, many with the condition had been left simply lying in bed or on the floor.As Spoan progresses, physical limitations worsen with age and by 50, nearly all patients become fully dependent on carers.This is the case for Inés's children, who are among the oldest in Serrinha. Chiquinho, 59, can no longer speak, and Marquinhos, 46, has limited communication abilities."It's hard to have a 'special' child. We love them the same, but we suffer for them," says Inés, who is married to a second cousin.
Larissa Queiroz, 25, the niece of Chiquinho and Marquinho, also married a distant relative. She and her husband, Saulo, only discovered their common ancestor after several months of dating."In Serrinha dos Pintos, deep down, we're all cousins. We're related to everyone," she says.Couples like Larissa and Saulo are the focus of a new research project which Santos is also involved in. Backed by Brazil's Ministry of Health, it will screen 5,000 couples for genes linked to serious recessive diseases.
The goal is not to stop cousin marriages, but to help couples understand their genetic risks, says Santos. Now a university professor, she also leads a genetics education centre and works to expand testing in the north-east of Brazil.Though she no longer lives in Serrinha dos Pintos, every visit feels like coming home."It's as if Santos is family," says Inés.

Try Our AI Features

Explore what Daily8 AI can do for you:

Learn with AIFact CheckingText to SpeechAI Summary

Related Articles

Reuters

17 hours ago

• Reuters

WOAH considers Brazil bird flu outbreak on commercial farm resolved

SAO PAULO, June 20 (Reuters) - The World Organisation for Animal Health (WOAH) considers a bird flu outbreak on a commercial farm in Brazil as "resolved," a page detailing the case on WOAH's website showed on Friday. Earlier this week, Brazil, the world's largest poultry exporter, declared itself free of bird flu in commercial flocks after observing a 28-day period without any new commercial farm outbreaks.

The Guardian

19 hours ago

• The Guardian

David Hopkinson obituary

My friend and former colleague David Hopkinson, who has died aged 89, was director of the Medical Research Council's human biochemical genetics unit at University College London from 1976 until its closure in 2000. Hoppy, as he was universally known, had joined the unit at its inception in 1962 because in an earlier, more junior, position he had been one of the first medical scientists to describe molecular differences in human enzymes, long before DNA sequence differences were known about. The unit was established to research the extent and significance of genetic variation to human health. As its head, Hoppy expanded its focus to gene mapping and disease genetics while also moving into the new science of gene cloning and DNA sequencing. Born in Chesterfield, Derbyshire, to Albert Hopkinson, an iron and steelworks foreman, and Lilian (nee Siddal), a dressmaker, he went to Chesterfield grammar school, which fostered his early interest in organic chemistry. After completing a natural sciences degree at Cambridge University he qualified in medicine at the London hospital in 1959, working there until he joined the human biochemical genetics unit three years later. Hoppy was recruited by its inaugural head, Prof Harry Harris, becoming his right-hand man responsible for many of the unit's innovative experimental approaches, including developing novel methods of enzyme detection and electrophoresis. The unit moved in 1965 from its initial base at King's College to UCL, where I joined the unit three years later to study for a PhD under Harris. Hoppy remained there for the rest of his career. He published widely, and played an important part in teaching and supervision, being made full professor of London University in 1990. Twenty five years after his retirement, his role as mentor is remembered with great warmth by his former staff and students. Hoppy read widely and appreciated drama and music. A practical man who took pleasure in manual labour, he was an accomplished gardener and delighted in propagating plants and growing vegetables. He also enjoyed summers hiking in the Swiss Alps, and was a keen birdwatcher. In retirement, he studied architecture and German, and gained a first-class degree in geology at the Open University. He also spent many years as a volunteer at Chilterns' Citizens Advice in Chesham, Buckinghamshire. He is survived by his second wife, Prof Yvonne Edwards, and by three children, Paul, Susan and Ian, from his first marriage, to Josephine (nee Manze), which ended in divorce, and four grandchildren.

The Independent

a day ago

• The Independent

The simple test that could predict how long you will live

A new study published in the European Journal of Preventive Cardiology explored whether a simple sitting-rising test could predict premature deaths. Researchers tested 4,282 adults aged 46-75 in Rio de Janeiro, Brazil, from 1998 to 2023, to evaluate non-aerobic physical fitness, including muscle strength, flexibility, and balance. The test required participants to sit and rise from the floor without using support from hands, elbows, or knees, with points deducted for any assistance or loss of balance. The study concluded that non-aerobic physical fitness, as assessed by this test, was a significant predictor of natural and cardiovascular mortality. After about 12 years, participants with a perfect 10 score had a 3.7 per cent death rate, while those scoring 0-4 points showed a dramatically higher death rate of 42.1 per cent.