Lecture 11 - Developmental and Genetic diseases

Question 1

the etiology of a disease can be…..

Answer 1

environmental
genetic
polygenic (combo of both)

Question 2

TRUE OR FALSE

genetic diseases are common

Answer 2

true

50% of miscarriages during early gestation have demonstrable genetic abnormality

Question 3

hereditary disease vs familial disease

Answer 3

hereditary is derived from parents

familial is transmitted from one generation to another

Question 4

genotype vs phenotype

Answer 4

genotype = genetic composition

phenotype = observed functional and morphological characteristics caused by genotype

Question 5

gene vs allele

Answer 5

gene is composed of 2 alleles. part of DNA sequence that codes for specific trait

allele is pair of genes on a particular chromosome at a particular place that controls the same characteristics like blood type

Question 6

genetic disorders can be characterized into what 4 categories

Answer 6

monogenic (mendelian)

multifactorial

chromosomal aberrations

mitochondrial disorders

Question 7

what is a monogenic (mendelian) disease

Answer 7

genetic disorder

mutation that affects ONE GENE that results in new change in fucntion/morphology

Question 8

what are multifactorial disorders

Answer 8

genetic disorder

due to polygenic factors – multiple genes or more than 1 environmental factor

Question 9

what are chromosomal aberrations

Answer 9

genetic disorder

abnormal number or structure of chromosomes

Question 10

what are mitochondrial disorders

Answer 10

genetic disordered

inherited from maternal side - very rare

Question 11

if a child has 1 affected parent and the pattern is autosomal dominant, what are the odds that the children will have the disease?

Answer 11

50-50

Question 12

true or false

males and females are equally affected by a trait that is autosomal dominant

Answer 12

true

Question 13

the phenotype expression of an autosomal dominant trait occurs with…..

Answer 13

a SINGLE COPY of a defective allele

Question 14

name 4 disorders that are autosomal dominant

Answer 14

achondroplasia
familial hypercholesterolemia
Huntington Disease
Neurofibromatosis Type 1

Question 15

true or false

achondroplasia has an autosomal recessive pattern

Answer 15

FALSE - autosomal dominant

Question 16

explain the morphological changes that occur in achondroplasia

Answer 16

shortened limbs (rhizomelia) with short hands and stubby fingers, notmal lenght torso

Question 17

_____ is the most common cause of dwarfism

Answer 17

achondroplasia

AUTOSOMAL DOMINANT

Question 18

Achondroplasia is caused by a mutation in what gene?

Answer 18

fibroblast growth factor receptor 3 gene
(FGFR3)

Question 19

the risk of a new mutation in the FGRF3 gene increases with…..
what disorder is this?

Answer 19

the age of the father

achondroplasia

Question 20

what are treatments for achondroplasia

Answer 20

support groups, growth hormon therapy

Question 21

________ is characterized by xanthomas

Answer 21

familial hypercholesterolemia (autosomal dominant)

xanthomas = cholesterol deposits in skin, tendons

Question 22

name 2 mutations that can result in familial hypercholesterolemia

Answer 22

LDLR gene - encodes LDL receptor protein which normally removes

apolipoprotein B (ApoB) - part of the LDL that binds to receptor

Question 23

heterozygous of LDLR gene may cause….

hmozygous of the LDLR gene may cause….

Answer 23

heterozygous may cause premature cardiovascular disease

homozygous may cause severe cardiovascular disease in childhood

Question 24

what is familial hypercholesterolemia treated with

Answer 24

statins
bile acid sequestrants
other lipid lowering agents

Question 25

explain Huntington Disease

Answer 25

affects basal ganglia of the brain - AUTOSOMAL DOMINANT

muscle spasms, amnesia, delusion, compulsive behavior, delirium, depression, anxiety, memory loss, tremors

NO CURE

Question 26

name 4 autosomal recessive disorders

Answer 26

cystic fibrosis
sickle cell disease
Tay-Sachs Disease
PKU (phenylketonuria)

Question 27

the phenotype expression of an autosomal recessive trait requires _____ cop(ies) of the defective allele

what about for autosomal dominant?

Answer 27

autosomal recessive = 2 copies

autosomal dominant = only 1 copy

Question 28

cystic fibrosis is involved with a defective……

Answer 28

CFTR (cystic fibrosis transmembrane conductance regulator)

whether it’s defective chloride secretion, not synthesizing the regulator at all, defective ATP binding to it, etc

Question 29

autosomal _______ skips a generation

Answer 29

recessive

Question 30

if someone has carrier parents ,what are the odds of them getting the disease for an autosomal recessive trait

Answer 30

25%

Question 31

what increases the risk for inheriting an autosomal recessive disease

Answer 31

cosanguinity (within family relations

Question 32

clinical manifestations of cystic fibrosis

Answer 32

copd - due to excess mucus production

pancreatic insufficiency
salivary gland obstruction
gall bladder stones
meconium ileus (bb first stool is blocking the ileum)

Question 33

manifestation of PKU (phenylketonuria)

Answer 33

musty odor in breath, skin, urine

skin rashes
lighter skin and hair color
small head
intellectually disabled
mental health
hyperactice

Question 34

what is the exact cause of PKU

Answer 34

phenylalanine can’t transform into melanin. thus, ppl need to follow diet that LIMITS phenylalanine

autosomal recessive

Question 35

sickle cell disease involves an infarction of what 4 things

Answer 35

lungs
kidney
spleen
bones

Question 36

those with sickle cell disease are at an increased risk for….

Answer 36

pneumococcal infections
fatal sepsis

Question 36

how is sickle cell disease diagnosed

Answer 36

hemoglobin electrophoresis

Question 37

true or false

sickle cell disease is autosomal recessive

Answer 37

true

Question 38

tay sachs disease is targeted where

Answer 38

in the nervous system

Question 39

what disease is characterized by a red spot in the retina?
how is it inherited?

Answer 39

tay sachs disease
autosomal recessive

Question 40

explain X-linked dominant pattern

Answer 40

affected males do NOT transmit the mutant allele to their sons

BUT affected males affect ALL of their daughters

these daughters have a 50% chance of transmitting the allele (to either M or F)

both males and females are affected, but women less severely

Question 41

give an example of an X-linked dominant disorder

Answer 41

Rett syndrome

Question 42

rett syndrome involves a mutation in what gene?

Answer 42

Methyl-Cp binding protein 2 gene (MECP2) on the X CHROMOSOME

Question 43

does rett syndrome affect girls, boys, or both?

Answer 43

occurs almost exclusively in girls (mutation on X chromosome)

but there are boys who have a similar mutation – Klinefelter’s Syndrome - have extra X chromosome XXY and die after being born

Question 44

true or false

there is no known cure for Rett Syndrome

Answer 44

true

Question 45

explain X-linked recessive pattern

Answer 45

affected male does NOT transmit allele to his sons

ALL daughters of an affected male are CARRIERS and NONE are affected

sons of these carrier females have 50% risk of being AFFECTED

daughters of these carrier females have 5-% risk of being CARRIERS

Question 46

true or false

in an X-linked recessive pattern, the most affected persons are female

Answer 46

FALSE - most are male

women are carriers.

affected male does not transmit to son, but all of his daughters will be carriers

these carrier daughters have 50% chance of making their sons AFFECTED and 50% chance of making their daughters CARRIERS

Question 47

Name 3 X-linked recessive disorders

Answer 47

Hemophilia B
XLA (x linked agammaglobulinemia)
Duchenne muscular dystrophy

Question 48

hemophilia B is caused by what mutation

Answer 48

in the factor IX gene – deficiency of factor IX - blood clotting disorder

Question 49

XLA is caused by mutation in what gene

Answer 49

in the BTK gene (Bruton Tyrosine Kinase)

Question 50

explain the pathophysiology of XLA

Answer 50

mutation in BTK gene = no maturation of pro b cells to b cells

antibody production is impaired

recurrent otitis media