Chromosomal homozygosity may or may not be caused by consanguineous marriages, but simply means that both parents carry the disease-causing gene.
When both parents carry a gene for an inherited disease, their offspring may be chromosomally compatible. Chromosome purity can be categorized into two main types: autosomal purity and sex chromosome purity.
In autosomal polymorphism, both men and women can develop the disease, while in sex chromosome polymorphism, it is usually seen only in women, i.e., both X chromosomes of the woman carry the disease-causing gene at the same gene locus.
In consanguineous marriages, both parents are more likely to carry the same disease-causing gene, and there may be two consecutive generations of persistent chromosome purity and disease. In the case of non-consanguineous marriages, the chances of chromosomal purity are lower, but not absent.
The offspring of consanguineous marriages may not always have chromosomal abnormalities, but the chance of occurrence is much higher than that of non-consanguineous marriages, so consanguineous marriages are currently prohibited in China.
If the offspring of a child develops a genetic disorder, it is recommended that screening for genetic disorders should be carried out in a timely manner in order to guide eugenic fertilization.