Genetic Disease Flashcards
(137 cards)
1
Q
A pathological condition caused by an absent or defective gene or by a chromosomal aberration
A
Genetic disorder
2
Q
How many genes that are involve in changes to their structure, causing disease
A
30,000
3
Q
Diseases derived from parents
A
Hereditary disorders
4
Q
Diseases transmitted in gametes through generation
A
Familial disorders
5
Q
True or False
Some congenital diseases are not genetic and not all genetic diseases are congenital
A
True
6
Q
What does mutations imply?
A
permanent changes in the DNA
7
Q
Mutations affecting ____ transmitted to progeny
A
germ cells
8
Q
Mutation affecting ____ does not transmit but casues cancers or malformations
A
somatic cells
9
Q
Enumarate types of mutations
A
- Point mutations (missesnse mutaions)
- Frameshift mutation
- Trinucleotide repeat mutations
10
Q
type of mutation
Substitution of single nucleotide base resulting in replacement of single amino acid in protein molecule
A
Point mutations (missense mutations)
11
Q
Example of disease in Point mutation
A
sickle cell anemia
12
Q
type of mutation
Insertion or deletion of one or two base pairs
A
Frameshift mutation
13
Q
type of mutation
Mutation that changes of DNA reading frame
A
Frameshift mutation
14
Q
Example of disease in Frameshift mutation
A
Tay-Sachs disease
15
Q
type of mutation
Amplification of 3 sequential nucleotides
A
Trinucleotide repeat mutations
16
Q
Example of disease in Trinucleotide repeat mutations
A
Fragile X syndrome
17
Q
Changing one letter in the sentence/(gene)
Original: The fat cat ate the wee rat
Point Mutation: The fat hat ate the wee rat.
A
Point Mutation
Original: The fat cat ate the wee rat
Point Mutation: The fat hat ate the wee rat.
18
Q
Adding or removing letters in a sentence/(gene)
Original: The fat cat ate the wee rat
Frame Shift: The fat caa tet hew eer at
A
Frame-shift mutation
Original: The fat cat ate the wee rat
Frame Shift: The fat caa tet hew eer at
19
Q
Removal of just one “word,” or longer deletions
Original: The fat cat ate the wee rat Deletion: The fat ate the
A
Deletion
Original: The fat cat ate the wee rat Deletion: The fat ate the
20
Q
Addition of extra word or extra DNA
Original: The fat cat ate the wee rat.
Insertion: The fat cat xlw ate the wee rat.
A
Insertion
Original: The fat cat ate the wee rat.
Insertion: The fat cat xlw ate the wee rat.
21
Q
Enumerate the different Genetic Disorders
A
- Mandelian Disorder
- Complex Disorders
- Chromosomal abnormalities
22
Q
Categories of Genetic Disorders
Resulting from mutations in single genes. These
diseases are hereditary and familial.
A
Mendelian Disorder
23
Q
Categories of Genetic Disorders
They include many uncommon
conditions, such as storage diseases and inborn errors of metabolism.
A
Mendelian Disorder
24
Q
Categories of Genetic Disorders
Involving multiple genes as well as environmental
influences or sometimes called multifactorial diseases.
A
Complex Disorders
25
# Categories of Genetic Disorders
They include some of
the **most common disorders** of mankind, including **hypertension**, **diabetes**,
and **allergic** and **autoimmune diseases**.
Complex Disorders
26
# Categories of Genetic Disorders
Changes in the number or structure of
chromosomes
Chromosomal abnormalities
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# Categories of Genetic Disorders
Several **rare developmental** abnormalities are attributable to
**chromosomes alterations**.
Chromosomal abnormalities
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Prevalence of Mandelian Disorders
Uncommon
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Penetrance of Mendelian Disorders
High
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Defect of Mendelian Disorders
Single Gene
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Prevalence of Chromosal Disorders
Uncommon
32
Penetrance of Chromosal Disorders
High
33
Defect of Chromosal Disorders
Chromosome structure/function
34
Prevalence of Complex Multigenic Disorders
Common
35
Penetrance of Complex Multigenic Disorders
Low
36
Defect of Complex Multigenic Disorders
Polymorphisms
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Enumerate the 3 **Mendelian** patterns of inheritance
* Autosomal Dominant disorder
* Autosomal Recessive disorders
* X-linked disorders
38
# Mendelian pattern of inheritance
Manifests in **heterozygous states**
Autosomal Dominant
39
# Mendelian pattern of inheritance
Mutation of **one allele**
Autosomal Dominant
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# Mendelian pattern of inheritance
Mutation of **one allele**
Autosomal Dominant
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# Mendelian pattern of inheritance
**At least one parent is affected**, males/female;** both can transmit**
Autosomal Dominant
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# Mendelian pattern of inheritance
**Enzyme proteins** not affected but receptors and *structural proteins are involved;
onset late sometimes*
Autosomal Dominant
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Examples of Autosomal Dominant disorders
Marfan’s syndrome, Achondroplasia, Huntington’s disease
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# True or False
If an affected person marries an unaffected individual, every child has *40%* chance of
inheriting the disorder
False; 50%
45
# Disorders
Examples of Autosomal Dominant in the Nervous System
* Huntington’s Disease
* Neurofibromatosis
* Myotonic Dystrophy
* Tuberous sclerosis
46
# Disorders
Examples of Autosomal Dominant disorders in the Skeletal System
* Marfan Syndrome
* Ehlers-Danlos Syndrome (some variants)
* Osteogenesis Imperfecta
* Achondroplasia
47
Example of Autosomal Dominant disorder of the Urinary System
Polycystic kidney disease
48
Examples of Autosomal Dominant disorder of the Gastointestinal tract
Familial polyposis coli
49
Hematopoietic examples of Autosomal Dominant disorder
* Hereditary spherocytosis
* Von Willebrand Disease
50
Metabolic examples of Autosomal Dominant disorder
* Familial Hypercholesterolemia
* Acute intermittent porphyria
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# Categories of Genetic Disorders
Largest group; both copies (alleles) are mutated;
Autosomal Recessive
52
# Categories of Genetic Disorders
Parents asymptomatic (trait); but children show disease
Autosomal Recessive
53
# Categories of Genetic Disorders
Siblings have 1 in 4 chance of being affected (25% risk)
Autosomal Recessive
54
# Categories of Genetic Disorders
Possibility more in consanguineous marriage
Autosomal Recessive
55
# Categories of Genetic Disoders
Possibility more in consanguineous marriage
Autosomal Recessive
56
# Categories of Genetic Disorders
Males and females equally affected; early onset
Autosomal Recessive
57
# Categories of Genetic Disorders
It involves enzyme proteins
Autosomal Recessive
58
Example of Autosomal Recessive disorder that involves enzyme proteins
* Cystic Fibrosis
* Wilson’s disease
* Sickle cell anemia
59
Metabolic examples of Autosomal Recessive disorder
* * Cystic fibrosis
* PKU
* Galactosemia
* Homocystinuria
* Lysosomal Storage Diseases
*Α1 – Antitrypsin Deficiency
* Wilson Disease
* Hemochromatosis
* Glycogen Storage Diseases
60
Hematopoietic examples of Autosomal Recessive disorder
* Sickle Cell Anemia
* Thalassemias
61
Examples of Autosomal Recessive disorder of the Endocrine System
* Congenital Adrenal hyperplasia
62
Examples of Autosomal Recessive disorder of the Nervous System
* Neurogenic Muscular Atrophies
* Friedreich Ataxia
* Spinal Muscular Atrophy
63
Examples of Autosomal Dominant disorder of the Skeletal System
* Ehlers Danlos Syndrome (some variants)
* Alkaptonuria
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# Categories of Genetic Disoder
Sex-linked disorders
X-linked
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# Categories of Genetic Disorder
all are X-linked, no Y’s yet
X-linked
66
# True or False
most X-linked disorders are recessive
True
67
It is transmitted by ____ females to their sons
heterozygous
68
# True or False
affected males do transmit to sons and daughters become
carriers
Do NOT
| affected males do not transmit to sons but daughters become
carriers
69
Examples of X-lined disorders
Hemophilia, Duchenne muscular dystrophy
70
Often appear before age six and it is commonly characterized by calf muscle hypertrophy, scoliosis, developmental delay, learning differences, delayed speech
Duchenne Muscular Dystrophy (DMD)
## Footnote
includes: scoliosis, short stature, freq. falls, difficult climbing, toe walk, progressive muscle weakness and atrophy,
71
Often appear before age six and it is commonly characterized by calf muscle hypertrophy, scoliosis, developmental delay, learning differences, delayed speech
Duchenne Muscular Dystrophy (DMD)
## Footnote
includes: scoliosis, short stature, freq. falls, difficult climbing, toe walk, progressive muscle weakness and atrophy,
72
Examples of X-linked disorders in the Musculosketal
Duchenne muscular dystrophy
73
Examples of X-linked disorders in the Blood
* Hemophila A and B
* Chronic granulomatous disease
* G6PD deficiency
74
Examples of X-linked disorders in the Immune
* Agammaglobulinemia
* Wiskott-Aldrich Syndrome
75
Metabolic examples of X-linked disorders
* Diabetes Insipidus
* Lesch-Nyhan Syndrome
76
Examples of X-linked disorders in the Nervous system
Fragile X syndrome
77
# Numeric Abnormalities of Chromosal Abnormalities
May affect autosomes or sex chromosomes.
CHROMOSOMAL
ABNORMALITIES
78
Enumerate 2 abnormalities of Chromosomal abnormalities
Numeric Abnormalities and Structural Abnormalities
79
# Numeric Abnormalities of Chromosal Abnormalities
What is the normal chromosal count
The normal chromosomal count is 46
80
# Numeric Abnormalities of Chromosal Abnormalities
What is the normal chromosal count
The normal chromosomal count is 46
81
How many chromosal count from each parent
that is 2n=46; 23 from each parent
82
How many autosomes are there from each parent
22 autosomes
83
How many sex chromosome from each parent?
1 sex chromosome
| X or Y chromosome
84
What sex chromosome/s can you receive from your mother
X chromosome
85
What sex chromosome/s can you receive from your father
X or Y chromosome
86
exact multiple of haploid number (2n)
Euploid
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increasing multiples (3n or 4n)
Polypoid
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increasing multiples (3n or 4n)
Polypoid
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results in spontaeneous abortion
Polypoid
90
not an exact multiple of n
Aneuploid
91
Extra information
Gametes then have an extra chromosome (n+1) or one less (n-1);
Fertilization of such gametes by normal gametes result in 2n+1 (Trisomy) or
2n-1(monosomy)
92
These result from chromosomal breakage followed by loss or rearrangement of material
Structural Abnormalities
93
Enumerate the different loss/rearragement of Structural Abnormalities
* Translocation
* Isochromosomes
* Deletion
* Inversions
* Ring chromosomes
94
Chromosomes:
Chromosomes:
*Described as having short arm (p=petit) and long arm (q)
*Each arm then divided into numbered regions (1,2,3….) from the centromere outward
*Each region has bands that are numerically arranged
*Thus 2q34 = chromosome 2, long arm, region 3, band 4
95
________ deviations in sex chromosomes are compatible
with life
Extreme karyotype deviations in sex chromosomes are compatible
with life
96
Why?
This is believed to be due to the
* Lyonization (inactivation) of X chromosome and
* scant genetic information carried by the Y chromosomes.
97
All but one X chromosome is ____ and so a 48, XXXX female has only one active X chromosome
inactivated
98
The inactive X, forms a discrete body within the nucleus called a
Barr body
99
How many Barr body does a normal female have
Normal females (XX) will have** one Barr body**
100
How many Barr bodies does a normal male have
None, Normal males (XY) or (XO) individuals will have no Barr bodies
101
# Chromosomal disorders occur:
Due to absence
deletion, monosomy
102
# Chromosomal disorders occur:
Due to absence excess
(trisomy)
103
# Chromosomal disorders occur:
Due to absence abnormal
arrangements
(translocations) of chromosomes
104
Loss effects, more severe defects than ____
gain
105
_____ are better tolerated than autosome abnormalities
Sex chromosome abnormalities
106
Sex chromosome disorders are ____ and sometimes are not detected at birth e.g.
infertility
subtle
107
Usually chromosomal disorders are the result of ____ changes. Hence if
parents are normal, risk of recurrence in siblings is low; exception _____
Usually chromosomal disorders are the result of **de novo** changes. Hence if
parents are normal, risk of recurrence in siblings is low; *exception* **Down syndrome**
108
Down Syndrome is also known as
Trisomy 21
109
What is the cause of Trisomy 21
* Meiotic non-disjunction of chromosome 21
* results in extra chromosome count
(47; 2n+1)
110
Mostly, parents are normal; Incidence increases with _____
maternal age
111
In a few (familial form), translocation occurs from chromosome ----- to chromosome ------ or -------
In a few (familial form), translocation occurs from chromosome** 21** to chromosome **22** or
**14 **(no extra)
112
Trisonomy 21 is marked by
◦ Severe mental retardation
◦ Large forehead, broad nasal bridge, wide-spaces eyes, epicanthal folds, large
protruding tongue
◦ Brushfield’s spots (white spots on the iris)
◦ Short, broad hands with curvature of the fifth finger
◦ Simian crease, a single palmar crease
◦ Unusually wide space between 1st and 2nd toes
113
"white spots on the iris"
Brushfield's spots
114
a single palmar crease
Simian crease
115
Trisonomy 18
Edward's Syndrome
116
**Mental retardation**, prominent occiput, **micrognathia**, low set ears, short
neck, **rocker-bottom feet**, flexion deformities of the fingers and **congenital
heart disease**
Edward's Syndrome
117
Is manifested by mental retardation, **microcephaly,** microphthalmia, brain
abnormalities, **cleft lip** and palate, polydactyly, rocker-bottom feet, umbilical
hernia, **renal defects** and congenital heart disease.
PATAU’S SYNDROME
118
Cri Du Chat
Cry of a cat
119
Cry of a cat is also known as
Le Jeune's Syndrome
120
LE JEUNE’S SYNDROME is caused by deletion of the short arm of -----
chromosome 5
121
LE JEUNE’S SYNDROME is marked by severe ---, ---- and unusual ----.
Severe **mental retardation**, **microcephaly** and unusual **catlike cry**.
122
Low birth rate (LBW), round face, hypertelorism, low set ears and epicanthal folds
LE JEUNE’S SYNDROME
123
Male hypogonadism, with 2 X and 1 or more Y chromosomes e.g. 47, XXY
Klinefelter’s syndrome
124
What can be seen in Klinefelter's Syndrome
Single Barr body on buccal smear
125
contributing factors of klinefelter's syndrome
* Advanced maternal age
* irradiation of either parents
126
Features of Klinefelter's syndrome
* Atrophic testis
* tall stature
* eunuchoid appearance gynecomastia
* mental retardation (mild)
127
------ testosterone production and ----- pituitary gonadotropins
**Decreased** testosterone production and **increased** pituitary gonadotropins
128
Have associated disorders of klinefelter's syndrome
like cancers (breast) or autoimmune diseases (SLE)
129
causes Hypogonadism in females; Is most common cause of primary amenorrhea.
Turner's Syndrome
130
how many barr body does a px with turner's syndrome have
No Barr body
131
# True or False
Turner's Syndrome does NOT complicated by mental retardation
True
132
Ovaries are replaced by fibrous -----
Ovaries are replaced by fibrous streaks
133
----- estrogen production and ------ pituitary gonadotropins
**Decreased** estrogen production and **increased** pituitary gonadotropins
134
Infantile genitalia and poor breast development
Turner's Syndrome
135
**Short stature**, **webbed neck**, shield like chest with **widely spaced nipples**, **higharched palate**, and a wide carrying angle of the arms (**cubitus valgus**).
Turner's Syndrome
136
Bicuspid aortic valve, coarctation of aorta, horse-shoe kidney
Turner's Syndrome
137
Lymphadema of extremities, cystic hygroma
Turner's Syndrome
