Question:

A friend is pregnant and they have found out that the fetus has half of a Y chromosome. What are the implications of a diagnosis like this for a fetus? What is the medical term for this condition? Thank you

Answer:

From your question it is difficult to say what the implications are for the fetus. It is not clear whether the fetus is missing part of the Y chromosome or has extra Y chromosome material.

Humans have 46 chromosomes. Of those, two chromosomes are the sex chromosomes – females have 2 X`s and males have an X and Y. The are only a small number of genes that have been mapped to the Y chromosome – but some of those play a critical role in male development. Depending on what part of the Y chromosome is missing or is added – there may be no associated problems or there could be problems with normal development, infertility, etc.

The medical term for such a condition would describe the part of the Y that is missing (deleted) or added – there is no “name” for these types of chromosomal abnormalities.

If your friend has not spoken to a geneticist or genetic counselor, I would recommend that they do so. The genetics team could provide them with specific information based on the exact Y chromosome abnormality seen. They can ask their doctor for a referral or contact the website below to locate a genetics center near them.

For more information:

National Society of Genetic Counselors Resource Link

Response by:

Anne Matthews, R.N., Ph.D. Director, Genetic Counseling and Family Studies Center for Human Genetics School of Medicine Case Western Reserve University