Chromosome Disorders Are a major Category of Genetic Disease 1% of live births 2 of prenatal diagnoses in women >35 yrs old 50% of all first trimester spontaneous abortionsChromosome Disorders Are A Major Category of Genetic Disease – ~ 1% of live births – ~ 2% of prenatal diagnoses in women >35 yrs old – 50% of all first trimester spontaneous abortions