Birth defects mainly include chromosomal diseases, single gene genetic diseases, congenital malformations, and multifactorial genetic risk factors. Birth defects are mainly regulated by three factors: heredity, environment, and the interaction between heredity and environment. Based on genetic factors, birth defects can be divided into three types of diseases: chromosomal diseases, genomic diseases, monogenic diseases. Chromosomal diseases usually include abnormal chromosome numbers and large fragment structural aberrations. Genomic diseases include chromosomal microdeletions/microduplicatins. Monogenic diseases are an important component of genetic defects, and pre- pregnancy/early pregnancy carrier screening is a preventive test for birth defects caused by severe single gene diseases.
Annoroad's carrier screening product during the peri-conceptional period [Kaiyun' an] includes 18 diseases with high carrier frequencies in the Chinese population: 5 metabolic diseases, 3 diseases with mental retardation, 3 deafness, 3 blood diseases, 2 muscle diseases, 1 endocrine disease, and 1 skin disease. 18 monogenic diseases involve more than 400+ hot spot mutations of 18 genes.