Post-mortem findings in a fetus with 48,XXY,+21

Area of Science:

• Medical Genetics
• Prenatal Diagnosis
• Fetal Abnormalities

Background:

• Advanced maternal age is a significant risk factor for fetal chromosomal abnormalities.
• Routine amniocentesis is a common method for prenatal screening.
• Simultaneous detection of multiple chromosomal aneuploidies can occur.

Purpose of the Study:

• To report a rare case of a fetus with concurrent Klinefelter syndrome (XXY) and Down syndrome (+21).
• To investigate potential tissue-limited mosaicism in a fetus with combined aneuploidies.
• To correlate prenatal findings with post-mortem examination results.

Main Methods:

• Karyotyping via amniocentesis at 15 weeks gestation.
• Fibroblast culture and cytogenetic analysis from six fetal tissues post-termination.
• Post-mortem examination and ultrasound review.

Main Results:

• The fetus presented with a 48,XXY,+21 karyotype.
• All analyzed fetal tissues exhibited the same karyotype, ruling out tissue-limited mosaicism.
• Bilateral clinodactyly of the fifth finger was the sole phenotypic abnormality noted, consistent with ultrasound findings.

Conclusions:

• Advanced maternal age necessitates careful prenatal screening for chromosomal abnormalities.
• Combined aneuploidies like XXY and +21 can be detected prenatally.
• This case highlights the importance of comprehensive genetic analysis in prenatal diagnosis.