Genetics Flashcards
Genetic Anticipation
Condition that presents earlier and more severe in successive generations
Genetic Heterogeneity
Different Genetic mutations causing same disease
Germline Mosaicism
Unaffected parents having Gametes with mutated allele that is passed to offspring
Maternal Imprinting
Selective silencing of genes inherited from mother. The expression of genes are determined by information from fathers side
Example of Genetic Anticipation
Myotonic Dystrophy
Example of Genetic Hetrogeneity
Tuberous sclerosis
Example of Maternal Imprinting
Prader-Willi Syndrome
Stop Codons
UAA
UAG
UGA
G6PD enzyme function
Converts glucose 6 phosphate to 6-phosphogluconate
Down Syndrome GI Complications
Duodenal Atresia and Hirschsprung Disease
Down Syndrome Malignancy
ALL
Almond Shaped Eyes, Narrow Forehead, Short Stature, Obese and hypogonadism
Prader-Willi Syndrome
Long Narrow Face, Prominent Forehead and chin, large everted ears
Fragile X Syndrome
Flat Occiput with bilateral epicanthal folds, single palmar crease
Downs Syndrome
Prominent occiput, Low set ears and small jaw
Edwards Syndrome
Polydactyly, Rocker bottom feet, Cleft Lip and Cleft palate
Patau Syndrome
Fragile X syndrome Trinucleotide Repeat
CGG
The 5 As of Down syndrome:
- Advanced maternal age
- Atresia (duodenal)
- Atrioventricular septal defect
- Alzheimer disease (early onset)
- ALL
Key Features of Kartagener’s Syndrome
Infertility
Recurrent Sinus Infections
Chronic Cough
Pleiotropy
when one gene contributes to multiple seemingly unrelated phenotypic effects. This phenomenon explains how a single gene mutation can cause a disease affecting multiple organ systems
Variable Expressivity
Two individuals can have exactly the same mutation on the same chromosome (i.e., same genotype), but show a different degree of disease manifestation and severity
Anticipation
Pattern of inheritance in which the succeeding generation develops a disease with greater severity or at a younger age than the ones before
MECP2 gene mutation
Rett Syndrome
Almond Shaped eyes, Obesity and Narrow Bridge of Nose
Prader-Willi Syndrome
Frontal Balding and Cataracts
Myotonic Dystrophy
Trinucleotide repeat of CTG
Myotonic Dystrophy
Inheritance pattern of Lesch-Nyhan syndrome
X-linked recessive
Inheritance pattern of severe combined immunodeficiency (SCID)
Autosomal Recessive
mutation of the tumor suppressor p53 gene located on chromosome 17
Li-Fraumeni syndrome
Function of Retinoblastoma gene
Prevents cell-cycle progression past the G1/S checkpoint
Lens subluxation downward and inward
Homocystinuria
Lens subluxation upward and outward
Marfan syndrome
maple syrup urine disease caused by
α-keto acid dehydrogenase deficiency
t(14;18) translocation
Follicular B-cell lymphoma
Function of α-keto acid dehydrogenase
Breaks down isoleucine, leucine, and valine (Branched amino acid)
What is the role of the mRNA start codon AUG in prokaryotes in the innate immune response?
Codes for N-formylmethionine (fMet) → stimulate neutrophil chemotaxis
Which ophthalmologic finding may be present in a patient with Down syndrome
Brushfield spots (whitish spots at the margin of the iris)
A mutations affects male and female offspring with equal frequency, but disease often presents
with varying severity even in those with the same mutation
Heteroplasmy
A defect in fibrillin-1 is associated with
Marfan syndrome.
Intestinal rupture
Thin skin
Bruising and varicosities
Suggestive of
Vascular Ehlers-Danlos syndrome
