downs syndrome is caused by

HESI LPN

HESI Maternal Newborn

1. What causes Down's syndrome?

A. Alcohol abuse by the mother at the time of conception.
B. Sex-linked chromosomal abnormalities.
C. An extra chromosome on the 21st pair.
D. Drug abuse by the mother during pregnancy.

Correct answer: C

Rationale: Down's syndrome, also known as trisomy 21, is caused by the presence of an extra chromosome on the 21st pair. Choice A is incorrect as alcohol abuse is not the cause of Down's syndrome. Choice B is incorrect because Down's syndrome is not related to sex-linked chromosomal abnormalities. Choice D is also incorrect as drug abuse by the mother during pregnancy is not the cause of Down's syndrome.

2. Following an amniocentesis, a nurse is caring for a client. The nurse should observe the client for which of the following complications?

A. Hyperemesis
B. Proteinuria
C. Hypoxia
D. Hemorrhage

Correct answer: D

Rationale: After an amniocentesis, the nurse should monitor the client for potential complications, with hemorrhage being a significant concern due to the invasive nature of the procedure. Hyperemesis (severe vomiting), proteinuria (excessive protein in the urine), and hypoxia (low oxygen levels) are not typically associated with amniocentesis and are less likely to occur compared to hemorrhage, which is a more common complication that requires prompt recognition and intervention.

3. Rico is a man who has enlarged breasts and suffers from mild mental retardation. He has a problem learning languages, and his body produces less of the male sex hormone testosterone than normal males. Rico is most likely suffering from:

A. Klinefelter syndrome.
B. Tay-Sachs disease.
C. Turner syndrome.
D. Down syndrome.

Correct answer: A

Rationale: Rico's symptoms align with Klinefelter syndrome, which is characterized by an extra X chromosome in males (XXY). Enlarged breasts (gynecomastia), mild mental retardation, learning difficulties, and reduced testosterone production are common features of Klinefelter syndrome. Choice B, Tay-Sachs disease, is a genetic disorder that affects the nervous system and is not associated with the symptoms described. Choice C, Turner syndrome, occurs in females with a missing or partially missing X chromosome and does not fit Rico's profile. Choice D, Down syndrome, is caused by an extra copy of chromosome 21 and typically does not present with the symptoms mentioned for Rico.

4. What is the purpose of amniocentesis?

A. To induce abortion
B. To detect genetic abnormalities in the fetus
C. To determine the baby's gender
D. To monitor fetal growth

Correct answer: B

Rationale: Amniocentesis is a diagnostic procedure used to detect genetic abnormalities in the fetus, such as chromosomal disorders like Down syndrome. It is not performed to induce abortion. The primary purpose of amniocentesis is to assess the genetic health of the fetus, not to determine the baby's gender (Choice C). While amniocentesis can provide information about the baby's health and development, it is not primarily used for monitoring fetal growth (Choice D). Therefore, the correct answer is B.

5. _____ is a type of estrogen, prescribed in the 1940s and 1950s to pregnant women, that is said to have caused testicular, vaginal, and cervical cancer in some offspring.

A. Androsterone
B. Adiponectin
C. Progestin
D. Diethylstilbestrol

Correct answer: D

Rationale: Diethylstilbestrol (DES) is a synthetic estrogen that was prescribed to pregnant women in the 1940s and 1950s to prevent miscarriages. However, it was later discovered that DES exposure in utero could lead to health issues in offspring, including an increased risk of testicular, vaginal, and cervical cancer. Choice A, Androsterone, is a steroid hormone produced in small amounts in humans and unlikely to be associated with the adverse effects described. Choice B, Adiponectin, is a protein hormone that plays a role in regulating glucose levels and fatty acid breakdown, not related to the adverse effects mentioned. Choice C, Progestin, is a synthetic form of progesterone used in birth control and hormone therapy, not linked to the specific health concerns associated with DES exposure.