It might happen so that the abnormal cell separation ends up the way it should not be. Additional genetic material from 21 chromosomes appears. That is what causes a so-called down syndrome. Being a simple form at first, it may become rather serious of not diagnosed on time. People who suffer from this syndrome experience difficulty with everyday activities that require at least a bit of intellectual load. It prevents from healthy development.
Slow muscle development is another symptom. The ligaments required to provide a healthy activity of various body parts need more time to develop than in healthy person. The low-speed development of the muscles causes their weakness. Because of that, patients with this symptom are under the threat of other disorders associated with bones and muscles such as spinal cord compression.
Speaking about the physical qualities, it seems that the patients with Down syndrome have too short necks. It is one of the disorders which can be noticed by the physical appearance of the person, not only internal problems. In more than 80% of all cases, children and even newborn babies demonstrate obvious physical deviations. The length of the neck is then beyond the average. The symptom may disappear with age.