Ancient DNA Reveals Earliest Genetic Diagnosis in a Stone Age Teenager
A new study has unveiled groundbreaking insights into a Stone Age individual, buried approximately 12,000 years ago in an Italian cave. DNA analysis of the skeleton confirmed it belonged to a teenage girl who possessed a rare genetic disorder causing shortened arms and legs – a rare form of dwarfism. This remarkable finding represents the earliest DNA diagnosis of a genetic disease in an anatomically modern human, pushing back such discoveries by millennia.
Researchers stated this is the earliest DNA-confirmed genetic diagnosis ever made in humans, predating previous diagnoses by about 10 millennia.
Unveiling the Genetic Past
Earliest Genetic Diagnosis
This discovery is hailed as the earliest DNA-confirmed genetic diagnosis ever made in humans, predating previous diagnoses by about 10 millennia. It also marks the earliest diagnosis of a rare disease and the earliest familial genetic case identified from ancient remains.
Condition Identified
The teenager, now identified as Romito 2, was diagnosed with acromesomelic dysplasia, Maroteaux type (AMDM). This specific condition leads to extreme shortening of the limbs, notably the forearms, forelegs, hands, and feet.
Genetic Cause
AMDM is directly linked to mutations on both chromosomes of the NPR2 gene, a gene critical for proper bone growth. Romito 2's condition would have presented significant challenges with movement and daily activities throughout her life.
Physical Characteristics
Romito 2 stood approximately 3 feet, 7 inches (110 centimeters) tall. Initial research had mistakenly identified the skeleton as male; however, DNA testing from the inner ear definitively confirmed it was female.
A Bond of Kinship and Community Care
Romito 2 was discovered buried in an embraced position with an adult, identified as Romito 1, within the Romito Cave in southern Italy. DNA testing further revealed that Romito 1 was also female and a first-degree relative, strongly suggesting a mother-daughter or sister-sister relationship.
Intriguingly, Romito 1 was also shorter than the average adult of her period, measuring 4 feet, 9 inches (145 cm), and carried one abnormal copy of the NPR2 gene. In contrast, Romito 2 carried two abnormal copies, which resulted in her more pronounced dwarfism.
The genetic material confirmed that both individuals belonged to the Villabruna genetic cluster, a group of hunter-gatherers who expanded across Southern, Central, and Western Europe approximately 14,000 years ago. While the local population was likely small, no evidence of close inbreeding was detected among them.
The precise cause of death for Romito 1 and Romito 2 remains unknown, as their remains exhibit no signs of trauma. Notably, Romito 2's diet and nutritional status were found to be consistent with others buried in the cave, indicating that her community provided dedicated care despite her physical challenges.