What Does Having an Extra X Chromosome Mean?

Question

What does having a chromosome with one being 47XXX mean?

Answer

For women, an abnormality in the number of sex chromosomes can manifest as having one fewer X chromosome or more than N chromosomes. In real life, the “Barbie doll” falls into the latter category, known as the ‘superfemale syndrome.’ More accurately, this condition is called ‘XXX syndrome’ or ‘polyX syndrome.’ The normal female karyotype is (46,XX), while patients with the ‘superfemale syndrome’ have three main types of karyotypes: one extra X chromosome, i.e., (47,XXX), or two extra X chromosomes, i.e., (48,XXXX). Even in Guangdong, there was a case of a woman with six X chromosomes, with a karyotype of (50,XXXXX), which is extremely rare and has led to some people humorously referring to women with the ‘superfemale syndrome’ as ‘superwomen.’ The prevalence rate of the ‘superfemale syndrome’ among women is as high as 0.08%, meaning that out of every 1250 female babies born, one has an extra X chromosome. From a physical standpoint, women with the ‘Barbie doll’ syndrome after puberty are taller than average women and have a slender and tall figure. In medical terms, this is described as ‘proportionally disproportional body parts,’ meaning that when the arms are stretched out to both sides, the distance between the middle fingers is greater than the height, similar to the slender and tall body type of the ‘Barbie doll.’