A familial polymorphic variant of chromosome 5

Area of Science:

• Human Genetics
• Prenatal Diagnosis
• Cytogenetics

Background:

• Elevated maternal serum alpha-fetoprotein (AFP) is a common indicator for prenatal genetic screening.
• Amniocentesis is a diagnostic procedure used to assess fetal genetic health.

Observation:

• Two male fetuses, undergoing amniocentesis due to high maternal AFP levels, were identified with a chromosomal abnormality.
• The anomaly involved an anomalous chromosome 5, characterized by a large heterochromatic segment on the long arm.

Findings:

• Both male fetuses carried the anomalous chromosome 5.
• One fetus exhibited an additional ring chromosome, suggesting a more complex genetic rearrangement.

Implications:

• This finding highlights a rare chromosomal variation associated with elevated AFP levels.
• Further investigation is warranted to understand the clinical significance and inheritance patterns of this specific chromosome 5 anomaly.