Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

MOD Exam 1 > Genetics > Flashcards

Genetics Flashcards

1
Q

What is the cystic fibrosis mutation?

A

CFTR on chromosome 7q31.2

Autosomal recessive

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

What is the most common mutation in alpha1-antitrypsin deficiency?

A

PIZZ

High risk for hepatocellular carcinoma and emphysema

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

What is thalassemias and what causes them?

A

Mutation in globin gene affects amount of globin chains synthesized

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

What kind of adverse drug reaction do G6PD def patients have?

A

Adverse reaction to antimalarial drug primaquine. Leads to severe hemolytic anemia.

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

What is the most common mutation seen in Marfan syndrome? How does it manifest?

A

AD, FBN1 Chr 15Q21.1

Defect in extracellular glycoprotein, fibrillin-1, leads to loss of structural support and excessive activation of TGF-beta signaling.

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

What gene defects cause classic E-D syndrome (type I and II)?

A

COL5A1 and COL5A2

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

What gene defect causes vascular E-D syndrome (type IV)?

A

COL3A1

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

What gene defect causes kyphoscoliosis E-D syndrome (type VI)?

A

Lysyl hydroxylase

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

What is the enzyme deficiency in Tay-Sachs? What does this lead to an accumulation of?

A

Hexosaminidase A deficiency

Leads to accumulation of GM2 ganglioside

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

What is the enzyme deficiency in Gaucher? What does this lead to an accumulation of?

A

Glucocerebrosidase deficiency (chr 15)

Leads to accumulation of glucocerebroside

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

What is the enzyme deficiency in Niemann-Pick? What does this lead to an accumulation of?

A

Sphingomyelinase deficiency

Leads to accumulation of sphingomyelin

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

What is the enzyme deficiency in MPS I Hurler? What does this lead to an accumulation of? How is it inherited?

A

alpha-L-iduronidase deficiency (autosomal recessive)

Leads to accumulation of dermatan sulfate and heparan sulfate

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

What is the enzyme deficiency in MPS II Hunter? What does this lead to an accumulation of? How is it inherited?

A

L-Iduronosulfate sulfatase deficiency (X-linked recessive)

Leads to accumulation of dermatan sulfate and heparan sulfate

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

What are some hallmarks for Tay-Sachs?

A

Ashkenazic Jews. Motor and mental defects start to manifest at 6 mo. Cherry red spot in macula. Death by 2-3 years.

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

What are some hallmarks for Niemann-Pick?

A

Ashkenazic Jews. Severe neuro damage in type A. No neuro damage in type B. Progressive neuro damage in type C. Zebra bodies. Massive splenomegaly. May have cherry red spot.

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

What are some hallmarks for Gaucher?

A

No CNS involvement in type I, jewish, 90% of cases. Acute neuronopathic in type II, not jewish, early death. Intermediate CNS involvement in type III.

Distended phagocytic gaucher cells in liver, spleen, and BM. Enlarged spleen. Pancytopenia or thrombocytopenia. “Crumpled tissue paper”

17
Q

What are some hallmarks for Hurler vs Hunter?

A

Hurler: AR. Norm at birth, death by 6-24 due to cardiovascular complications. Clouding of the cornea.

Hunter: X-linked. No corneal clouding. Milder.

Both have zebra bodies and balloon cells (PAS+). Both have hepatosplenomegaly.

18
Q

What is a hepatic form of glycogenoses? What are the hallmarks of it?

A

Von Gierke. Glucose-6-phosphatase def. High glycogen in liver, low blood glucose.

19
Q

What is a myopathic form of glycogenoses? What are the hallmarks of it?

A

McArdle dz. Muscle phosphorylase def. High glycogen storage in muscle and muscle weakness. No increase in blood lactate after exercise.

20
Q

What type of glycogenoses has a acid maltase def?

A

Pompe dz. Leads to cardiomegaly.

21
Q

What is a Robertsonian translocation?

A

Centric fusion. Translocation between 2 acrocentric chromosomes, typically breaks appear closer to the centromeres. Leads to 1 very large chromosome and an extremely small one that is usually lost. Typically has normal phenotype. Can lead to Trisomy 21 if 3 copies of long arm of chr 21.

22
Q

What are the main hallmarks of trisomy 21?

A

Epcanthic folds. One long crease in palm. 40% have congenital heart disease, most commonly defect in endocardial cushion and/or septal defects. Risk of developing acute leukemia. Develop changes characteristic of alzheimers. Abnormal immune responses lead them predisposed to serious infections.

23
Q

What are some hallmarks of Edwards (trisomy 18)?

A

Renal malformations, mental retardation, rocker bottom feet. Limited hip abduction.

24
Q

What are some hallmarks of patau syndrome (trisomy 13)?

A

Cleft lip and palate. Polydactyly. Renal defects. Mental retardation. Rocker-bottom feet. Umbilical hernia.

25
Q

What are the hallmarks of Chr 22q11.2 deletion syndrome?

A

Congenital heart defects, abnormalities of the palate, facial dysmorphism. Variable degrees of immunodeficeincy and hypocalcemia.

26
Q

What are the two main types of Chr 22q11.2 deletion syndrome and their differences?

A

DiGeorge syndrome: Thymic hypoplasia with T cell immunodeficiency, parathyroid hypoplasia. Leads to hypocalcemia and cardia malformations. Mild facial anomalies. CATCH 22

Velocadiofacial syndrome: facial dysmorphism, cleft palate, cardiovascular anomalies, learning disabilities.

27
Q

What is the genotype and hallmarks of Klinefelter syndrome?

A

47, XXY. Male hypogonadism. Not dx until puberty. High risk for DM2 and metabolic syndrome. Risk for mitral valve prolapse, osteoporosis, and fractures. Lack of secondary male characteristics. Male infertility. High risk of breast cancer and autoimmune diseases.

28
Q

What is the genotype and hallmarks of Turner syndrome?

A

45, XO. Female hypogonadism (most common). Can be complete or partial monosomy, partial is more common. Congenital heart disease, bicuspid aortic valves. Short stature. Menopause occurs before menarche. STREAK OVARIES. Half develop antibodies to thyroid leading to hypothyroidism. Obesity is common. Most common cause of primary amenorrhea.

Cystic hygroma: infant with edema, swelling of the nape of the neck due to lymph stasis. Leads to bilateral neck webbing.

29
Q

What kind of mutation causes fragile X syndrome?

A

Trinucleotide repeat mutation leading to a loss of function (non-coding region). CGG triplet. X-linked recessive.

30
Q

What kind of mutation causes Huntington disease?

A

Trinucleotide repeat mutation leading to toxic gain of function (coding region). CAG triplet. Autosomal dominant. Chromosome 4.

31
Q

What kind of mutation causes fragile X tremor-ataxia syndrome?

A

Trinucleotide repeat mutation leading to toxic gain of function mediated by mRNA (noncoding region). CGG triplet.

32
Q

What is the morphologic hallmark seen in all trinucleotide repeat mutations?

A

Accumulation of aggregated mutant proteins in large intranuclear inclusions.

33
Q

What are the hallmarks of fragile X syndrome?

A

Second most common cause of mental retardation after down. More common in males. Long face, large mandible, large elevated ears, hyperextensible joints, high arched palate.

Most distinctive feature is macro-orchidism (large testicles)

34
Q

What are some of the atypical patterns of transmission seen in fragile x syndrome.

A

20% of males can by clinically and cytogenetically normal. More repeats seem to be added during oogenesis, so it is amplified in female offspring. 30-50% of carrier females are affected.

Anticipation: Clinical features of fragile x worsen with each successive generation.

35
Q

What are the hallmarks of huntington disease?

A

Jerky movements. Rigidity. Atrophy of brain. Repeat expansions occur during spermatogenesis, so onset is earlier with each generation. (anticipation).

36
Q

What is heteroplasmy?

A

Tissues and individuals that harbor both wild type and mutant mtDNA.

37
Q

What is leber hereditary optic neuropathy (LHON) and how is it inherited?

A

Neurodegenerative disease that manifests as progressive bilateral loss of central vision. Also has cardiac conduction defects and minor neurologic manifestations. mtDNA disorder.

38
Q

What is the difference in inheritance between Angleman and Prader-Willi?

A

Angleman: deletion in maternal chromosome with paternal imprint.

Prader-Willi: deletion in paternal chromosome with maternal imprint.

In both cases, this leads to nonfunctioning alleles in both chromosomes (15q11.2-q13)

39
Q

What are the symptoms seen in Angleman and Prader-Willi?

A

Angleman: Mental retardation, ataxic gait, seizures, and inappropriate laughter. “Happy puppets”

Prader-Willi: Mental retardation, short stature, hypotonia, profound hyperphagia, obesity, small hands/feet, and hypogonadism.

MOD Exam 1 (2 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions