General Vocab

Question 1

Hypogonadotropic hypogonadism

Answer 1

a condition in which the hypothalamus or the pituitary gland do not produce the hormones that signal to the testes (in males) or the ovaries (in females) to produce sex hormones

Question 2

Dystonia

Answer 2

a movement disorder that causes the muscles to contract involuntarily. This can cause repetitive or twisting movements.

Question 3

opisthotonus

Answer 3

is a state of severe hyperextension and spasticity in which an individual’s head, neck and spinal column enter into a complete “bridging” or “arching” position.

Question 4

Hypoketotic hypoglycemia

Answer 4

low blood glucose concentration in the absence of ketone bodies in the urine

Question 5

Reye-like syndrome

Answer 5

acute noninflammatory encephalopathy with hyperammonemia, liver dysfunction, and fatty infiltration of the liver

Question 6

HELLP syndrome

Answer 6

hemolysis, elevated liver enzymes, and low platelet count; severe complication of pregnancy

Question 7

Semi-dominant inheritance

Answer 7

In incomplete dominance, both alleles contribute to the phenotype additively.
The heterozygous phenotype shows an intermediate between the homozygous phenotypes.

Question 8

Dyspraxia

Answer 8

is a neurodevelopmental condition that begins in childhood that makes it difficult to perform motor skills. It also causes issues with coordination.

Question 9

Hypergonadatropic hypogonadism

Answer 9

little or no hormone is produced by the testes or ovaries. The condition can be hypergonadotropic (primary, resulting when the gonads fail)

Question 10

Locus heterogeneity

Answer 10

mutations in different genes can cause the same disorder/phenotype

Ex: autism, RP

Question 11

Allelic heterogeneity

Answer 11

different mutations/alleles in the same gene can cause the same disorder

Ex: CF

Question 12

Phenotypic heterogeneity (aka genetic heterogeneity)

Answer 12

different mutations in the same gene can cause different phenotypes

ex: FGFR2 associated conditions (Apert, Crouzon, Pfeiffer)

Question 13

Pleiotropy

Answer 13

one gene mutation influences many unrelated phenotypic traits

ex: PKU and SCA affect multiple body systems

Question 14

Variable expressivity

Answer 14

one condition can have many different phenotypes. Phenotypes can vary widely between relatives with the same variant

ex: NF1

Question 15

Penetrance

Answer 15

How likely a mutation in a gene is to lead to dz. Reduced penetrance results in variant carriers who may not ever present w dz

Question 16

What is the liability threshold/genetic liability? What does it apply to?

Answer 16

multifactorial conditions that are more common in one sex than another
to have the trait, the person has to meet genetic and environmental factors that cause them to be predisposed to it
think of the u/s findings and which sex is more likely to have the phenotype

Question 17

What % of cancers are hereditary

Answer 17

10%

Question 18

Describe the two hit hypothesis

Answer 18

used to describe cancer development
“two hits” or mutations (one on each gene copy) initiate cancer development or inhibit ability to destroy cancerous cells
when people have a germline mutation, all of their cells already have one hit
the second hit is a somatic mutation that occurs randomly on the other copy of the same gene that has a germline mutation
non-hereditary cancers also require two hits, but both are somatic

Question 19

Define tumor suppressor genes. Give some examples

Answer 19

regulate cell division and tell cells when to die; acts like a brake pedal and keeps the cell from dividing too quickly

when there is a mutation, cell division can get out of control and transform into cancer; cause cancer when they are turned OFF
ex: Rb, p53, APC, BRCA1/2, NF1/2

Question 20

Define oncogenes

Answer 20

regulate cell division; act like a gas pedal when mutated, pushing the cell to divide

can cause ca when they are turned on; a non-mutated oncogene is called a PROTO-oncogene

Question 21

Define DNA repair genes. Give examples

Answer 21

reduced ability to repair DNA damage when somatic mutations occur (mutations from tobacco use, UVR, aging, random)
mismatch repair genes (Lynch): MSH2, MSH3, MSH6, MLH1, PMS2
Nucleotide excision repair genes (xeroderma pigmentosum, Cockayne syndrome)
Fanconi anemia genes

Question 22

Rhizomelia

Answer 22

short proximal long bones

Question 23

Mesomelia

Answer 23

short distal long bones

Question 24

Acromelia

Answer 24

short hands and feet

Question 25

Amelia

Answer 25

absent limbs

Question 26

micromelia

Answer 26

all parts of the long bones are shortened/small