Question
What is Down syndrome? Does having three pairs of the 21st chromosome mean the fetus has a deformity?
Answer
Down syndrome occurs when a fetus has an extra 21st chromosome, resulting in three chromosomes of this type, known as trisomy 21 or Down syndrome. Patients often have various abnormalities in organs and tissues, including a small head, a round face, widely spaced eyes, prominent epicanthal folds, thick lips, and a large tongue, as well as separated rectus abdominis muscles. Intelligence development is also affected, with an IQ typically ranging from 25 to 50. Additionally, patients often have congenital heart disease and digestive tract abnormalities, with an average lifespan of about 16.2 years. However, through training and treatment, patients can learn to perform more labor-intensive tasks, and the gap in IQ can become more apparent with age growth.