The story begins in February 2023. Pregnant with her sixth child, Ashley Zambelli (23) performs a prenatal screening for trisomy 21. The result comes shortly after: her baby has Down syndrome.
The young American (who lives in the state of Michigan) is not really surprised: in 2019 already, her first child (unfortunately died during a miscarriage) had been diagnosed positive. And a year later, in 2020, Ashley gave birth to a baby with trisomy 21. In total, of the couple’s six children, three are affected by Down syndrome.
Faced with this statistical exception (on average, in France, the “risk” of giving birth to a baby with Down syndrome is only 1 case for 1600 births!), the doctors offer the young mother to take a genetic test. . Surprise: Ashley’s karyotype reveals that she has mosaic trisomy 21.
Mosaic trisomy 21 is not necessarily visible to the naked eye
Mosaic trisomy 21: what is it? In people with mosaic Down syndrome, “abnormal” cells with 47 chromosomes (including 3 chromosomes 21) coexist with “normal” cells with 46 chromosomes (including 2 chromosomes 21). “The proportion of the two categories of cells varies considerably from one subject to another and, in the same individual, from one organ or tissue to another.” specifies theJerome Lejeune Institute.
Mosaic trisomy 21 remains rare since it affects approximately 1% of people diagnosed.
“People tell me: you don’t seem to be affectedreacted Ashley Zambelli on Instagram. Many associate trisomy 21 with facial features. But the disease is not always visible to the naked eye, especially when it presents in mosaic.“
“I am happy to have been diagnosed” she says today. The diagnosis of mosaic trisomy 21 allows her to understand certain symptoms that were difficult to explain until now: concentration problems at school, joint problems (at the level of the patella, in particular) or a permanently abnormally high heart rate.
Source : The Independent
