In prehistoric societies, children with Down syndrome who died young were buried with the usual honors, and in some cases even with strikingly beautiful grave goods. This is the conclusion of a team of scientists led by the Max Planck Institute for Evolutionary Anthropology in Leipzig. They published their findings on Tuesday in the magazine Nature Communications.
The researchers wanted to know how often certain genetic abnormalities occurred in prehistoric and historical populations and therefore tested the DNA in the remains of 9,855 people. They were looking for a condition called trisomy: a genetic condition in which three of a chromosome are present instead of the usual two. With trisomy of chromosomes 13, 18 and 21, children have Patau syndrome, Edwards syndrome and Down syndrome respectively.
Of the individuals studied, six suffered from Down syndrome: one came from a seventeenth-century grave in Finland, the remaining five were between 2,500 and 5,000 years old and came from cemeteries in Greece, Bulgaria and Spain.
The researchers also found a child in Spain with Edwards syndrome who probably died shortly after or just before delivery. Three children with Down syndrome died before birth, the other three did not live longer than one and a half years.
Porous skull bones
The six cases of Down syndrome in this study population amount to one case per 1,643 individuals. Nowadays that is one case per 705: significantly more often. The authors do not want to draw any far-reaching conclusions from this, because relatively few children’s graves from prehistoric times have been found, they write.
To test the findings of their genetic research, the team also looked for skeletal abnormalities associated with trisomy. Nearly all individuals suffering from Down syndrome had porous skull bones, and in two cases there was abnormal bone growth consistent with this condition. The girl with Edwards syndrome also had abnormal bone growth.
In all cases, the children were buried in the usual manner at that time, and sometimes even with additional honors. The boy from seventeenth-century Finland was given a Christian funeral, dressed as was customary at the time. The six Iron Age and Bronze Age individuals were all buried indoors. One of them – a girl about a year and a half old who lived around 1300 B.C. was buried on the Greek island of Aegina – was given a necklace with 93 beads of different colors and sizes.
Researchers found a head wound in a six-month-old boy from a grave in Bulgaria. That does not mean that he was killed violently, they emphasize. People with Down syndrome have relatively more frequent epileptic seizures, so a fall as a result of such an attack can also be the cause of the injury. Overall, the researchers conclude, “there is no evidence that [deze individuen] have been stigmatized in their communities in the past,” although it should be noted that because of their young age, “they may not have been visually identifiable as ‘different’.”