20 Facts Chromosome 1. Having a miscarriage can be due to a chromosome disorder 2. Monosomy is similar to those who have down syndrome 3. Infants with monosomy often have numerous birth affects 4. Down Syndrome affects between 1 in 600 to 1 to 800 infants 5. Women between the ages of 18 to 25 have a low risk of having a down syndrome baby 6. Age is the factor in calculating risk of trisomy 7. Familial Down Syndrome is second form of down syndrome 8. Familial down syndrome occurs as a results of the fusion of chromosome 21 to another all to some 9. About 10% of the live born children of carries have trisomy 21 10. Trisomy of chromosome 21 is commonly called down Syndrome 11. People with down syndrome are usually mentally retarted and often have heart defects 12. Babies born to mothers over 35 have a high risk of having a baby with down syndrome 13. Age 50 and over is probability of having a child with down syndrome is 1 in 12 14. Majoring of down syndrome causes seem to a rise nondisjunction during meiosis 15. Roughly 75% of the nondisjunction responsible for down syndrome occur during the first phase of meiosis 16. Cell division – monoamines can occur in cells as a result of mistakes 17. Occurs when once extra copy of a chromosome is present is called Trisomy 18. Monosomy occur when one chromosome lack its homoloy 19. 8% of all conceptions are aneupliod 20. Monosomy 21 and Monosomy 13 are result of nondisjunction during meiosis