Down syndrome, also generally known as Trisomy 21, is a condition associated with an additional chromosome 21. and, results in some developmental differences. The ratios you mentioned are actually the chances that a test-based diagnosis of Down syndrome of this kind will prove to be real. On one hand, people sometimes may have specific features and varying symptoms such as developmental delays along with specific physical features, but a lot of them live meaningful lives if assistance is available and many lead scaffolding lives with themselves and among others. It's a good idea to report your findings to a healthcare provider who can offer you his own personal advisories and resources. The programs of the early period of intervention can so much develop and improve one's life, that along with the doctor's consultation, you can think whether the doctor's suggestions you doctor-visit or some other method better for your child are.