👤 whose
Whose work first linked an extra chromosome 21 to Down syndrome?
Human BiologyGenetics
Quick Answer
Jérôme Lejeune and colleagues identified the extra chromosome 21 in 1959. This was the first chromosome abnormality tied to a major human genetic syndrome.
The Full Story
In 1959, Jérôme Lejeune, Marthe Gautier, and Raymond Turpin found that Down syndrome is caused by trisomy 21, meaning three copies of chromosome 21 instead of the usual two. This was the first clear link between a specific chromosomal abnormality and a human developmental disorder. The discovery transformed pediatrics and genetics. It also opened the door to prenatal chromosome testing and modern cytogenetics.
Key Facts
1.Down syndrome was linked to trisomy 21 in 1959
2.Humans usually have 46 chromosomes
3.Trisomy 21 means 47 chromosomes total
YouTube Angle
Suggested video title for this topic:
"The chromosome discovery that explained Down syndrome"