Down syndrome,Turner syndrome,and Klinefelter syndrome are the most common chromosomal disorders world-wide.Down syndrome is caused by an extra copy of the 21st chromosome and has an incidence of 1 in 800 to 1000 live...Down syndrome,Turner syndrome,and Klinefelter syndrome are the most common chromosomal disorders world-wide.Down syndrome is caused by an extra copy of the 21st chromosome and has an incidence of 1 in 800 to 1000 live births.Turner syndrome results from X-chromosome monosomy and has an incidence of 1 in 2000 of live-born female infants.展开更多
文摘Down syndrome,Turner syndrome,and Klinefelter syndrome are the most common chromosomal disorders world-wide.Down syndrome is caused by an extra copy of the 21st chromosome and has an incidence of 1 in 800 to 1000 live births.Turner syndrome results from X-chromosome monosomy and has an incidence of 1 in 2000 of live-born female infants.
