Congenital Abnormalities

Question 1

When is the period of vulnerability?

Answer 1

2-15 weeks post-conception during organogenesis

Question 2

What are teratogens?

Answer 2

Any factor present in the environment of the embryo or mother causing birth defect

Question 3

What mono genie abnormalities are there?

Answer 3

Autosomal dominant, autosomal recessive, and X-linked recessive

Question 4

What is an autosomal dominant genetic abnormality?

Answer 4

There is a 50% chance of inheriting the defective gene, one parent has the defective gene

Question 5

What is an autosomal recessive genetic abnormality?

Answer 5

Two defective genes must be present in order for the defect to be expressed, 50% carrier, 25% unaffected, and 25% affected

Question 6

What is a X-linked recessive genetic abnormality?

Answer 6

Males are always affected because this defect occurs on the X chromosome. Females have another X to make up for the defective X whereas males have a Y which does not make up for the defective X

Question 7

Which parent is a mitochondria gene disorder inherited from and why?

Answer 7

The mother because maternal gametes contain more mitochondria than paternal gametes as most of the mitochondria is lost in the tail of the sperm when it falls off

Question 8

What type of defects are often seen in mitochondria gene disorders and why?

Answer 8

Neuromuscular defects because mitochondria genes code for proteins that make up systems in the body that create ATP and without those systems there is not enough ATP for muscles

Question 9

What is a complex trait genetic abnormality?

Answer 9

It is a polygenic defect that involves a gene coupled with the environment

Question 10

What types of chromosomal abnormalities are there?

Answer 10

Numerical and structural abnormalities

Question 11

What is a numerical chromosomal abnormality?

Answer 11

Aneuploidy, too many or too little chromosomes in a pair

Question 12

What is trisomy?

Answer 12

An extra chromosome in a pair, making there three chromosomes

Question 13

What is monosomy?

Answer 13

A chromosome missing from a pair

Question 14

What is Down’s syndrome called?

Answer 14

Trisomy 21

Question 15

Describe Kleinfelter’s Syndrome

Answer 15

Trisomy on the sex chromosomes that affects males. Males have an extra X chromosome (XXY)

Question 16

What are clinical manifestations of Kleinfelter’s syndrome?

Answer 16

Enlarged breasts, small testes, infertility, long limbs, and lack of facial and body hair

Question 17

Describe Turner’s syndrome

Answer 17

Affects females. Female is missing one X chromosome (XO)

Question 18

What are clinical manifestations of Turner’s syndrome?

Answer 18

Poor breast development, webbed neck, small stature, infertility, and broad chest

Question 19

What are three structural deficits of chromosomal abnormalities?

Answer 19

Inversion, translocation, and deletion

Question 20

What is deletion?

Answer 20

Deleting part of a chromosome and losing genetic material

Question 21

What is translocation?

Answer 21

Exchange of segments of chromosomes

Question 22

What types of inversion are there?

Answer 22

Pericentric and paracentric

Question 23

What is pericentric inversion?

Answer 23

Two breaks in a chromosome that invert around the centromere

Question 24

What is paracentric inversion?

Answer 24

Two breaks in a chromosome with the fragment inverting but remaining on same arm, not around centromere

Question 25

What are congenital abnormalities a result from?

Answer 25

Developmental errors during gestation