Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Biochemistry > Genetics > Flashcards

Genetics Flashcards

(43 cards)

Start Studying
1
Q

Prader-Willi Syndrome is a genetic deletion of what?

What are the characteristics?

A

Paternal gene on Chromosome 15

Obesity, hypogonadism, hyperphagia, and hypotonia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Angelman Syndrome is a genetic deletion of what?

What are the characteristic?

A

Maternal deletion of Chromosome 15

Inappropriate laughter, seizures, ataxia, intellectual disabillity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the formula for Hardy-Weinberg population genetics?

A

p^2 + 2pq + q^2 = 1
p^2= frequency of homozygosity for allele p
q^2= frequency of homozygosity for allele q
2pq= frequency of heterozygosity

If disease is X-linked recessive the fequency in males = q and the frequency in females = q^2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

When is heteroplasmy inheritance present?

A

In mitochondrial DNA, therefore present in mitochondrially inherited diseases. (look for “ragged red fibers”)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How can you tell if an inheritance pattern is AD?

A

1/2 of children are affected

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How can you tell if an inheritance pattern is AR?

A

It is usually only present in 1 generation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How can you tell if an inheritance pattern is XR?

A

Sons of carrier mothers have it and there is no male to male transmission

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

How can you tell if an inheritance pattern is XD?

What are some examples of diseases?

A

Fathers transmit to all daughters but to no sons

Ex: Hypophosphatemic Ricketts (Vit D resistant Ricketts), Rett Syndrome, Alport Syndrome, Fragile X Syndrome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How can you tell if an inheritance pattern is mitochondrially inherited?

A

Variable expression due to heteroplasmy, look for “ragged red fibers”

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How do mitochondrial myopathies present?

A

Present with myopathy, lactic acidosis, and CNS disease.
Ex: MELAS syndrome- Mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes. This is due to a failure in Oxidative phosphorylation. Muscle biopsy shows “ragged red fibers”

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is mutated in achondroplasia?

A

fibroblast growth factor receptor 3 (FGFR3)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is mutated in ADPKD?

A

PKD1 on chromosome 16 (16 letters in “polycystic kidney”)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is mutated in Familial Adenomatous Polyposis?

A

APC gene on Chromosome 5q (5 letters in “polyp”)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is mutated in Familial hypercholesterolemia?

A

Defective LDL receptor (presents as early atherosclerosis, cornel arcus, and tendon xanthomas)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is mutated in Hereditary hemorrhagic telangiectasia?

A

blood vessel disorder resulting in arteriovenous malformations, recurrent epistaxis, branching skin lesions, hematuria, and GI bleeding. Also known as Osler-Weber-Rendu syndrome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is mutated in Hereditary spherocytosis?

Lab findings?

A

spectrin or ankyrin defect

increased MCHC & RDW

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is mutated in Huntington disease?

A

Gene on chromosome 4 resulting in increased tinucleotide repeats of CAG

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is mutated in Li-Fraumeni syndrome?

Study These Flashcards
A

TP53, presents as SBLA cancer (sarcoma, breast, leukemia, adrenal gland)

19
Q

What is mutated in Marfan syndrome?

Study These Flashcards
A

FBN1 gene on chromosome 15

20
Q

What is mutated in Multiple Endocrine Neoplasias (MEN)?

Study These Flashcards
A

MEN1 is associated with MEN1 gene defect

MEN2A and MEN2B are associated with RET gene mutations

21
Q

What is mutated in NF1?

Study These Flashcards
A

AKA: von Recklinghausen disease
presents with cafe-au-lait spots, cutaneous neurfibromas, pheochromocytomas, Lisch nodules (iris hamartomas)

Mutation in NF1 gene on chomosome 17 (“von Recklinghausen” has 17 letters)

22
Q

What is mutated in NF2?

Study These Flashcards
A

Presents with bilateral acoustic schwannomas, juvenile cataracts, meningiomas and ependymomas.
NF2 gene on chromosome 22

23
Q

What is mutated in VHL?

Study These Flashcards
A

Deletion of VHL gene on chromosome 3

24
Q

What is mutated in cystic fibrosis?

Study These Flashcards
A

CFTR gene on chromosome 7. This is a deletion of Phe508 and impairs posttranslational processing.

25
What is the pathophysiology of cystic fibrosis?
Abnormally thick mucus in the lungs and GI due to increased intracellular concentrations of Cl-, Na+, and H2O. Decreased ability to reaborb Cl- in sweat glands. This is due to a misfolded protein in the ATP-gated Cl- channel.
26
How can you diagnose Cystic Fibrosis?
Cl- concentration >60mEq/L in sweat
27
What are complications of cystic fibrosis?
Recurrent pulmonary infections, Pancreatic insufficiency, Infertility in men, Nasal polyps
28
What are the organisms responsible for recurrent pulmonary infections in early infants and adolescents in cystic fibrosis?
Infants- Staph aureus | Adolescence- P. aeruginosa
29
How does pancreatic insufficiency present in cystic fibrosis?
Meconium ileus in newborns.
30
How is cystic fibrosis treated?
Chest physiotherapy, albuterol, aerosolized dornase alfa, and hypertonic saline facilitate mucus clearance. Azithromycin is used as an anti-inflammatory Pancreatic enzymes are given as well
31
What are the XR disorders?
Oblivious Female Will Often Give Her Boys Her x-Linked Disorders: ``` Ornithine transcarbamylase deficiency Fabry disease Wiskott-Aldrich syndrome Ocular albinism G6PD deficiency Hunter syndrome Bruton agammaglobulinemia Hemophilia A & B Lesch-Nyhan syndrome Duchenne and Becker muscular dystrophy ```
32
What are the findings in Duchenne muscular dystrophy?
Cause: frameshift mutation that causes a deleted dystrophin gene. Dystophin helps to anchor muscle fibers in skeletal and cardiac muscle. Presentation: Weakness begins in the pelvic girdle and progresses superiorly. Patient will use the Gower maneuver to help them stand up. Fibrofatty replacement of muscle in the calf will result in pseudohypertrophy of calf muscles. Onset is before 5yo and dilated cardiomyopathy is the most common cause of death. Diagnosing: increase in creatinine kinase and aldolase are seen; Western Blot, muscle biopsy confirm
33
What are the findings in Becker muscular dystrophy?
Cause: non-frameshift mutation in the dystrophin gene. Presentation: Onset in adolescence
34
What are the findings in Myotonic Type 1 muscular dystrophy?
Cause: CTG trinucleotide repeat in the DMPK gene leading to altered myotonin protein kinase expression. Presentation: MY Tonia, MY Testicles (testicular atrophy), MY Toupee (frontal balding), MY Ticker (arrhythmia)
35
What are the findings in Fragile X Syndrome?
Cause: XD inheritance, CGG trinucleotide repeat in the FMR1 gene. Presentation: Fragile X = XL testes, jaw, ears Can lead to mitral valve prolapse
36
What diseases have trinucleotide expansion repeats?
Fragile X- CGG Friedreich ataxia - GAA Huntington - CAG Myotonic Dystrophy - CTG "X-Girlfriend's First Aid Helped Ace MY Test"
37
What are the findings in Down syndrome? 1st trimester findings? 2nd trimester findings?
1st trimester- increased nuchal translucency, hypoplastic nasal bone, decreased serum PAPP-A, increased free beta-hCG 2nd trimester- decreased alpha-fetoprotein, increased beta-hCG, decreased estriol, increased inhibin A
38
Edwards Syndrome 1st trimester? 2nd trimester?
Chr 18 trisomy, rocker-bottom feet, micrognathia, low set ears, clenched hands with fingers overlapping, prominent occiput 1st trimester- decreased PAPP-A and decreased beta-hCG 2nd trimester- decreased everything (alpha-fetoprotein, beta-hCG, estriol, inhibin A)
39
Patau Syndrome | 1st trimester?
Trisomy 13, rocker-bottom feet, cleft lip/palate, holoprosencephaly, polydactyly 1st trimester- decreased PAPP-A and decreased beta-hCG.
40
What chromosomes are likely to be involved in a Robertsonian Translocation?
13-15, 21 & 22
41
Cri-du-chat syndrome
Microdeletion of chromosome 5p | Presents as a high-pitched cryin/mewing, with possible VSD
42
Williams Syndrome
Microdeletion of chromosome 7q (elastin gene is included in deleted region) Presents with elfin facies, hypercalcemia, extreme friendliness with strangers, well developed verbal skills.
43
22q11 deletion syndromes DiGeorge Velocardiofacial
CATCH 22: Cleft palate, Abnormal facies, Thymic aplasia, Cardiac defects, Hypocalcemia (2' to PTH aplasia) Due to aberrant development of 3rd and 4th branchial pouches. DiGeorge- thymic, parathyroid and cardiac defects Velocardiofacial- palate, facial, and cardiac defects

Biochemistry (5 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions