Archive · 29 Dec 2025
Brazilian Woman Found with Male Blood Chromosomes
A woman in Brazil was surprised to learn that her blood had male chromosomes, even though she looked and functioned like a typical woman.
This happened after she had a miscarriage, and doctors did tests to find out why.
They found that her blood had male chromosomes (XY), but her skin had female chromosomes (XX).
This is very rare and is called chimerism, where two different sets of genes are in one body.
The woman had normal female body parts, normal hormone levels, and regular periods.
Doctors think chimerism is the reason for this unusual finding.
A 35-year-old Brazilian woman discovered male chromosomes in her blood after a miscarriage.
Genetic testing revealed her blood had XY chromosomes, while her skin had XX chromosomes.
Doctors confirmed no technical errors and repeated tests to verify the results.
The woman had normal female anatomy, hormone levels, and regular menstruation.
Chimerism, a condition where two sets of genes coexist in one body, was identified as the likely cause.
- Who
- A 35-year-old Brazilian woman
- What
- Discovered male chromosomes in her blood due to chimerism
- When
- After a miscarriage at 35 and during subsequent genetic testing
- Where
- Brazil
- Why
- Due to a rare condition called chimerism, where two sets of genes coexist in one body
- Patient's Age
- 35
- Chromosomes in Blood
- XY
- Chromosomes in Skin
- XX
- Condition
- Chimerism
- Miscarriage Week
- 7
- Puberty Onset
- 13
- Hormone Levels
- Normal
- Menstruation
- Regular