What is the pattern of inheritance for Down Syndrome?

Question

IS DOWN SYNDROME?:
Dominant or Recessive
Sex-linked or Autosomal
One gene or Polygenic

Answer 1

Down syndrome is classified under chromosomal abnormalities.

Numerical aberrations

Most folks have pairs of 23 different chromosomes. One set from your Mom; One set from your Dad, which equals 46 chromosomes. People with Down Syndrome somehow ended up with one extra #21 chromosome, they have 47 chromosomes.

Answer 2

Throughout the 20th century, advances in medicine and science enabled researchers to investigate the characteristics of people with Down syndrome. In 1959, the French physician, Jerome Lejeune, identified Down syndrome as a chromosomal anomaly when he observed 47 chromosomes present in each cell of individuals with Down syndrome instead of the usual 46. It was later determined that an extra partial or complete 21st chromosome results in the characteristics associated with Down syndrome.

Down syndrome occurs in one out of every 733 live births, and more than 350,000 people in the U.S. have this genetic condition. One of the most frequently occurring chromosomal abnormalities, Down syndrome affects people of all ages, races and economic levels