Her eyes are wide-set and slightly slanted. Her nose is short and flat, and she keeps her mouth slightly open. There is a straight crease across her palm, and her fifth digit is unusually short. The doctor tells her parents she has an inherited disorder. If you were the doctor what would you diagnosis Kate with? Discuss the etiology of Kate’s disorder? What is the biggest risk factor for this disorder? How can or will this disorder affect Kate? What test could have been completed to diagnosis this disorder before Kate’s birth?

- These morphological features belong to Down syndrome.

- Diagnosis: Down syndrome (Trisomy Extra chromosome 21).

- Etiology: the presence of three copies of the autosomal chromosome 21 instead of two copies in body (somatic) cells.

- Most important health problem: Down syndrome increases the risk of developing Alzheimer's disease (other health problems include heart congenital defects, vision problems, hearing loss, hypothyroidism)

- Diagnostic test: Amniocentesis

Explanation:

Down syndrome (DS) is the most frequent chromosomal abnormality which is generally caused by the presence of an extra copy of autosomal chromosome 21, thereby it is an autosomal trisomy (trisomy 21). DS is often associated with intellectual disability and increased risk of developing Alzheimer's, as well as health problems including, among others, heart congenital defects, vision problems, hypothyroidism, blood disorders, hypotonia, endocrine problems, dental problems, seizures, etc. Amniocentesis is the most common invasive prenatal diagnostic procedure which is used to identify chromosomal abnormalities such as trisomy 21 (Down syndrome). Amniocentesis is done between 15 weeks and 20 weeks of pregnancy.