Gen Path Exam 2 - Genetics Flashcards
What type of disease?
Marfan syndrome
Autosomal dominant - single gene disorder
What type of disease?
Familial hypercholesterolemia
Autosomal dominant - single gene disorder
What type of disease?
Cystic fibrosis
Autosomal recessive - single gene disorder
What type of disease?
Lysosomal storage disease
Autosomal recessive - single gene disorder
What type of disease?
Cleft palate
Complex multigenic disorder
What type of disease?
Down syndrome (trisomy 21)
Cytogenetic disorder
What type of disease?
Edwards syndrome (trisomy 18)
Cytogenetic disorder
What type of disease?
Patau syndrome (trisomy 13)
Cytogenetic disorder
What type of disease?
Klinefelter syndrome
Cytogenetic disorder
What type of disease?
Turner syndrome
Cytogenetic disorder
Transmitted in the parents’ gametes
Hereditary
Increased incidence among family members
Familial
Not necessarily hereditary, but might be
Familial
Present at birth
Congenital
Not necessarily genetic origin
Congenital
Permanent changes in DNA
Mutation
Germ cell mutation can be transmitted to progeny
Mutation
Somatic cell mutation is not transmittable
Mutation
What are the 2 types of genetic abnormalities?
Within DNA
Epigenetic inheritance
What are the categories of genetic abnormalities within DNA?
Smaller - gene level
Larger - chromosome level
What type of genetic abnormality within DNA?
Mutation
Smaller - gene level
What type of genetic abnormality within DNA?
Amplification
Larger - chromosome level
What type of genetic abnormality within DNA?
Deletion
Larger - chromosome level
What type of genetic abnormality within DNA?
Translocation
Larger - chromosome level
What type of genetic abnormality within DNA?
Inversion
Larger - chromosome level
What type of genetic abnormality?
Changes in regulation of gene expression, not sequence
Epigenetic inheritance
What type of genetic abnormality?
Heritable
Epigenetic inheritance
What type of genetic abnormality?
Caused by chemical modification of DNA, often induced by environment
Epigenetic inheritance
3 categories of genetic disorders
Single gene
Complex multigenic
Cytogenetic
Which category of genetic disorders?
Mutation in single gene
Single gene
Which category of genetic disorders?
One mutated copy of gene needed for disease to occur
Autosomal dominant - Single gene
Which category of genetic disorders?
Child of affected parent has 50% chance of inheriting disorder
Autosomal dominant - Single gene
Which category of genetic disorders?
2 mutated copies of gene required for disease to manifest
Autosomal recessive - Single gene
Which category of genetic disorders?
If both parents are carriers, each child has 25% chance of inheriting disorder
Autosomal recessive - Single gene
Which category of genetic disorders?
Mutations on X chromosome
X-linked - Single gene
Which category of genetic disorders?
Can be dominant or recessive
X-linked - Single gene
Which category of genetic disorders?
More likely to affect males
X-linked - Single gene
What disease?
Caused by mutation in fibrillin-1 gene (FBN1)
Marfan syndrome
ECM component of elastic fibers
Fibrillin-1 gene (FBN1)
What disease?
Clinical presentation includes tall thin stature, long arms/legs/fingers/toes, flexible joints, high arched palate, dislocation of ocular lens, mitral valve prolapse, aortic aneurysm and dissection, scoliosis
Marfan syndrome
What disease?
Diagnosed by clinical evaluation and genetic testing
Marfan syndrome
What disease?
Tx is antihypertensive meds and surgical intervention for aortic disease
Marfan syndrome
What disease?
Caused by mutation in LDL receptor gene (loss of function, lack of LDL uptake into liver, elevated LDL in plasma)
Familial hypercholesterolemia
What is one of the most common Mendelian disorders?
Familial hypercholesterolemia
What disease?
Clinical presentation is elevated LDL cholesterol, premature atherosclerosis/coronary artery disease, cholesterol deposits in skin
Familial hypercholesterolemia
Cholesterol deposits in skin
Xanthelasmas
What disease?
Diagnosed by cholesterol panel and genetic testing
Familial hypercholesterolemia
What disease?
Tx is statins and dietary changes
Familial hypercholesterolemia
What is the most common autosomal recessive disorder?
Cystic fibrosis
What disease?
Caused by mutation in CFTR gene
Cystic fibrosis
Affects chloride ion transport
CFTR gene mutation
Causes thick mucous secretions from exocrine glands
CFTR gene mutation
What disease?
Affects individuals of European descent
Cystic fibrosis
What disease?
Clinical presentation includes chronic respiratory infections, pancreatic insufficiency (protein/fat malabsorption, vitamin deficiency), salty sweat, poor growth
Cystic fibrosis
What disease?
Diagnosed by sweat test and genetic test
Cystic fibrosis
What disease?
Tx is respiratory therapy, enzyme supplements, antibiotics
Cystic fibrosis
What disease?
Caused by deficiency of lysosomal enzymes
Lysosomal storage diseases
What disease?
60+ types, categorized by deficient enzyme and accumulated metabolites
Lysosomal storage diseases
What are the 4 examples of Lysosomal storage diseases?
Gaucher disease
Tay-Sachs disease
Niemann-Pick disease
Mucopolysaccharidoses
Partially degraded metabolites accumulate in tissues
Lysosomal enzyme deficiency
Defective degradation of organelles leads to free radical production and apoptosis
Lysosomal enzyme deficiency
What disease?
More common in invididuals of Ashkenazi Jewish decent
Lysosomal storage diseases
What disease?
Often fatal in childhood
Lysosomal storage diseases
What disease?
Clinical presentation is progressive, CNS involvement, organ enlargement (liver, spleen), Gaucher disease, Mucopolysaccharidoses
Lysosomal storage diseases
Which specific Lysosomal storage disease?
Can cause radiolucent jaw lesions
Gaucher disease
Which specific Lysosomal storage disease?
Macroglossia; numerous impacted teeth w/ enlarged radiolucent follicles
Mucopolysaccharidoses
What disease?
Diagnosed by enzyme assays and genetic test
Lysosomal storage diseases
What disease?
Tx is enzyme replacement therapy
Lysosomal storage diseases
Which category of genetic disorders?
Combo of multiple genetic factors and environmental influences
Complex multigenic
Which category of genetic disorders?
No single mutated inherited gene
Complex multigenic
Which category of genetic disorders?
Multiple inherited genetic polymorphisms that predispose to disease
Complex multigenic
Which category of genetic disorders?
Do not follow clear Mendelian inheritance patterns
Complex multigenic
Which category of genetic disorders?
More challenging to predict inheritance
Complex multigenic
Which category of genetic disorders?
Environmental and lifestyle factors significantly influence whether inherited traits will be expressed phenotypically
Complex multigenic
What are the 3 categories within complex multigenic disorders?
Normal traits
Congenital traits
Diseases
Which category within complex multigenic disorders?
Intelligence
Normal trait
Which category within complex multigenic disorders?
Height
Normal trait
Which category within complex multigenic disorders?
Eye and skin color
Normal trait
Which category within complex multigenic disorders?
Cleft palate
Congenital defect
Which category within complex multigenic disorders?
Congenital heart defect
Congenital defect
Which category within complex multigenic disorders?
Type 1 and 2 diabetes
Disease
Which category within complex multigenic disorders?
Hypertension
Disease
Which category within complex multigenic disorders?
Gout
Disease
Which category within complex multigenic disorders?
Cancer
Disease
Which category within complex multigenic disorders?
Glaucoma
Disease
Which category within complex multigenic disorders?
Epilepsy
Disease
Which category within complex multigenic disorders?
Schizophrenia
Disease
What disease?
Associated with 400 developmental syndromes
Cleft palate
Name 3 developmental syndromes associated with cleft palate
Single-gene syndromes
Chromosome anomalies
Idiopathic
What disease?
Can be due to non-syndromic causes
Cleft palate
Name 3 non-syndromic causes of cleft palate
Major genes
Minor genes
Environmental factors
What environmental factors can cause cleft palate?
Maternal alcohol consumption
Maternal cig smoking
Maternal anticonvulsant therapy
What disease?
More common in men
Cleft palate
What disease?
Clinical presentation includes disturbance in fusion of palatal shelves, cleft palate, submucous palatal cleft, bifid uvula
Cleft palate
Communication btwn oral cavity and nasal cavity
Cleft palate
Surface mucosa intact
Submucous palatal cleft
Minimal manifestation of cleft palate
Bifid uvula
What disease?
Diagnosed by clinical exam and imaging
Cleft palate
What disease?
Tx is series of surgical repairs
Cleft palate
Which category of genetic disorders?
Abnormalities in chromosome structure/number
Cytogenetic
Which category of genetic disorders?
Structural abnormality
Cytogenetic
Which category of genetic disorders?
Deletion, duplication, translocation of chromosome segments
Cytogenetic
Which category of genetic disorders?
Aneuploidy
Cytogenetic
Abnormal number of chromsomes
Aneuploidy
Which category of genetic disorders?
Typically involve intellectual disabilities, physical abnormalities, congenital defects
Cytogenetic
Which category of genetic disorders?
Loss of chromosomal material more severe defects than gain
Cytogenetic
Which category of genetic disorders?
Imbalance of sex chromosomes tolerated better than autosomes
Cytogenetic
Which category of genetic disorders?
Sex chromosomal disorders can be subtle and may not be detected at birth
Cytogenetic
Which category of genetic disorders?
Lyonization
Cytogenetic
Only one X chromosome is active
Lyonization
Which category of genetic disorders?
Y chromosome caries only small amount of genetic info
Cytogenetic
Which category of genetic disorders?
Genetic result from de novo changes
Cytogenetic
Which category of genetic disorders?
Not inherited from parents
Cytogenetic
Which category of genetic disorders?
Recurrence in siblings is low
Cytogenetic
What disease?
Caused by 3 copies (trisomy) of chromosome 21
Down syndrome (trisomy 21)
What is the most common cytogenic disorder?
Down syndrome (trisomy 21)
What diseases?
Risk increases with advanced maternal age
Down syndrome (trisomy 21)
Edwards syndrome (trisomy 18)
Patau syndrome (trisomy 13)
What disease?
Clinical presentation is intellectual disability, distinct facial features, hypotonia, short stature, increased risk of congenital heart disease, increased risk of leukemia
Down syndrome (trisomy 21)
What disease?
Epicanthic folds and flat facial profile
Down syndrome (trisomy 21)
What disease?
Clinical presentation is macroglossia, gingivitis, perio, early tooth loss, candidiasis, resistance to caries due to more alkaline saliva, bruxism, mouth breathing, narrow palate/crowding, delayed eruption of permanent teeth
Down syndrome (trisomy 21)
What diseases?
Diagnosed by prenatal screening and genetic test after birth
Down syndrome (trisomy 21)
Edwards syndrome (trisomy 18)
Patau syndrome (trisomy 13)
What disease?
Tx is medical surveillance
Down syndrome (trisomy 21)
What disease?
Caused by 3 copies (trisomy) of chromosome 18
Edwards syndrome (trisomy 18)
What disease?
More common in females
Edwards syndrome (trisomy 18)
What disease is the 2nd most common cytogenic disorder?
Edwards syndrome (trisomy 18)
What disease?
Clinical presentation is heart defect, respiratory defect, prominent back of head, malformed low set ears, micrognathia (small mandible), index finger overlaps other fingers, clubbed feet
Edwards syndrome (trisomy 18)
What diseases?
Tx is supportive therapy
Edwards syndrome (trisomy 18)
Patau syndrome (trisomy 13)
What disease?
Median survival is 2.5-14.5 days
Edwards syndrome (trisomy 18)
What disease?
Fewer than 10% survive beyond 1st year
Edwards syndrome (trisomy 18)
What disease?
Caused by 3 copies (trisomy) of chromosome 13
Patau syndrome (trisomy 13)
What is the 3rd most common cytogenetic disorder?
Patau syndrome (trisomy 13)
What disease?
Clinical presentation is intellectual disability, microcephaly, microphthalmia (small eyes), cleft lip/palate, polydactyly, cardiac defects, renal defects, clubbed feet
Patau syndrome (trisomy 13)
What disease?
43% live longer than 1 week
Patau syndrome (trisomy 13)
What disease?
10% live longer than 5 years
Patau syndrome (trisomy 13)
What disease?
Caused by two X chromosomes and one Y chromosome
Klinefelter syndrome
What disease?
Caused by 47, XXY karyotype typically
Klinefelter syndrome
What disease?
Risk factors are advanced maternal age and history of irradiation in either parent
Klinefelter syndrome
What disease?
Clinical presentation is tall stature, reduced facial/body hair, gynecomastia (male breast development), feminine fat distribution, testicular atrophy, varicose veins, mild intellectual impairment
Klinefelter syndrome
What disease?
Increased risk of autoimmune disorder, breast cancer, venous thromboembolic disease, osteoporosis, infertility
Klinefelter syndrome
What disease?
Often diagnosed during/after puberty and genetic test
Klinefelter syndrome
What disease?
Tx is testosterone replacement therapy
Klinefelter syndrome
What disease?
Caused by female missing an X chromosome
Turner syndrome
What disease?
Caused by 45, X karyotype
Turner syndrome
What disease?
Advanced maternal age is a risk factor, but most cases are random
Turner syndrome
What disease?
Clinical presentation is short stature, webbing of neck, low posterior hairline, amenorrhea (lack of period), infertility, decreased female secondary sex characteristics, cardiovascular abnormalities, hypothyroidism
Turner syndrome
In Turner syndrome, what is the most common cause of death in childhood?
Cardiovascular abnormalities
What disease?
Diagnosed by genetic test
Turner syndrome
What disease?
Tx is growth hormone therapy and estrogen replacement
Turner syndrome
