Final answer:
Sex determination is the biological system that establishes sex in an individual, based on their sex chromosomes, XX in females and XY in males. Genetic counselors use this information to assist individuals and couples in understanding the risk of genetic disorders and can recommend DNA testing and genetic diagnosis techniques like PGD.
Step-by-step explanation:
Sex Determination
Sex determination in humans is the biological system that establishes the sex of an individual. It involves a pair of sex chromosomes: two X chromosomes in females (XX) lead to a female offspring while one X and one Y chromosome in males (XY) determine a male offspring. This is critical for genetic counseling, which is a process where individuals or couples can obtain advice about the likelihood of passing genetic disorders to their offspring.
Genetic Counseling
Furthermore, genetic counselors play a vital role in this process. They interpret family histories and provide risk estimates for future children to inherit genetic or chromosomal disorders. They may recommend testing such as blood tests for DNA analysis, amniocentesis, or chorionic villus sampling, which come with varying advantages and risks. These tests can reveal if a person is a carrier for genetic diseases such as Fragile X syndrome or cystic fibrosis.
PGD and Sex Selection
Preimplantation Genetic Diagnosis (PGD) is a technique used in conjunction with In Vitro Fertilization (IVF) to test embryos for genetic conditions before pregnancy. While PGD can be used ethically to prevent serious genetic diseases, its use in sex selection for non-medical reasons, such as family balancing, is ethically debatable and regulated differently across the world.