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Flashcards in genetics Deck (24):
1

Downs syndrome usually occurs due to

nondisjunction in Meiosis in the Ovum
(can also occur due to robertsonian translocation)
-advanced maternal age is a risk factor

2

pts with down's syndrome at risk for which cancers

AML ALL

3

acetylation of histones

enhances gene transcription

4

deacetylation of histones

silences the genes
-in HD, the mt huntington gene enhances the deacetylation of genes

5

hypermethylation of a transcription gene

leads to gene silencing

6

neonate with lymphemeda and cystic hygromas

tuners syndrome

7

t (15,17)

acute promyelocytic leukemia
-PML/RARalpha
M3 varian of AML
-younger pts, on smear see many auer rods, in

8

t(8,14)

Burkitts lymphoma
-c-myc translocated to immunoglobin gnee

9

t (9,22)

philadelphia chromosome, CML, bcr-abl

10

t (11, 14)

mantle cell B lymphoma
-activation of cyclin D gene

11

situs inversus + recurrent sinopulmonary infections

kartagener syndrome (immotile cilia syndrome)
-due to failure of dyenin arms to develop normally
-causes decreased clearing of epithelial cells
leads to infertility in men and can lead to infertility in women as well due to decreased fallopian tube cilia mobility
-autosomal recessive

12

neonate with low-set ears, clenched fists, overlapping fingers, micrognathia, microcephaly, arnold chiari, rocker bottom feet, HYPERtonia, VSD, PDA, Meckels, malrotation

Edwards, trisomy 18
-key abnormal hand (clenched with overlapping fingers)

13

cleft lip/palate, micropthalmia, coloboma, cyclops, deafness, scalp defects, PDA

Patau, trisomy 12
-most die within week and others rarely survive past 6 months,

14

ataxia, cardiomyopathy, pes cavus, hammer toes, kyphoscoliosis,

Friedrich ataxia
-chromosome 9, increaased trinucleotide repeats
-10% also develop Diabetes mellitus
death usually by cardiomyopathy and/or bulbar dysfunction

15

multiple telangiectasia of skin and mucosa with recurrent epistaxis

hereditary hemorrhagic telangiectasia (Osler-Rendu-Weber syndrome)

16

FGFR 3 mutation

achondroplasia (dwarfism)
autosomal dominant, lethan in homozygous dominant
-therfore heterozygous person has 50% chance of having a short kid

17

ectopia lensis, MR, vascular thromboses, marfanoid, osteoporosis

homocystinuria,
cystathionine beta synthase deficiency
an example of pleiotrophy

18

increased AFP
increased Ach

Neural tube defects

19

hypotonia, poor feeding, macroglossia, jaundice, constipation, hoarse cry

congenital hypothyroidism
prevents normal brain devleopment and myelination during early life
-also at higher risk of congenital heart risk (ASD/VSD)
-irreversible mental retardation,
-a normal screening test

20

chromosome 22 long arm deletion

DiGeorge
CATCH 22
Cleft lip/cardiac anomalies like interrupted aortic arch
Abnormal facies
Thymic hypoplasia-recurrent viral infection due to decreased T cell maturation
Hypocalcemia due to pit abnormalities

21

t (14,18)

follicular lymphoma (a non-Hodgkin lymphoma)
leading to overexpression of bcl-2--> a proto-oncogene tha tprevents the release of pro-apoptotic factors)
14-immunoglobin heavy chain enhancer

22

histone located outside of nucleosome core

Histone H1, aid in DNA packing of regions between each core making entire structure more tight
inside (H2A, H2B, H3, H4)X2

23

genetics of Alzheimer's

ApoE4 associated with familial late onset AD
Presenilin 1 on chr 14, presenilin 2 on chr 1, and amyloid precursor protein on 21 associated with early onset AD

24

polygenic conditions

-androgenetic alopecia
-epilepsy
-schizophrenia
-glaucoma
-ischemic heart disease
-hypertension
-TIID
-malignancy