Related Experiment Videos
True vs. false inv(Y)(p11q11.2): a familial instance concurrent with trisomy 21
Horacio Rivera1, Melva Gutiérrez-Angulo, Hilda Gómez-Sánchez
1División de Genética, Instituto Mexicano del Seguro Social, Ap. Postal 1-3838, Jalisco, Guadalajara, Mexico. hrivera@cencar.udg.mx
Annales De Genetique
|July 18, 2002
Summary
A boy with Down syndrome and a rearranged Y chromosome, identified as a pericentric inversion, highlights two types of Y chromosome inversions. This common Y chromosome variation typically has no impact on fertility or phenotype.
Area of Science:
- Human Genetics
- Cytogenetics
- Reproductive Biology
Background:
- Down syndrome (Trisomy 21) is a common genetic disorder.
- Y chromosome inversions (inv(Y)) are recognized polymorphisms.
- Understanding Y chromosome structural variations is crucial for genetic counseling.
Observation:
- A case report of a boy with Trisomy 21 and a metacentric Y chromosome with a pericentric inversion (inv(Y)(p11q11.2)).
- The Y chromosome exhibited mitotic stability and specific hybridization patterns, suggesting a 'true' inversion.
- The concurrence of Trisomy 21 and inv(Y) was considered coincidental due to their individual frequencies.
Findings:
- Classification of Y chromosome pericentric inversions into 'true' (single, alphoid centromere, stable) and 'false' (non-alphoid centromere, unstable) types.
- The observed Y chromosome in the proband fits the criteria for a 'true' inversion.
- The study reinforces that Y chromosome inversions are generally benign, with no reported effects on fertility or phenotype in humans or other mammals.
Implications:
- Provides a framework for classifying Y chromosome inversions based on centromere type and mitotic stability.
- Highlights the importance of distinguishing between stable and unstable Y chromosome rearrangements.
- Contributes to the understanding of Y chromosome polymorphism and its genetic consequences, or lack thereof.