Genetics

Question 1

dysmorphology

Answer 1

study of abnormal form

Question 2

congenital anomaly

Answer 2

abnormality present at birth from any cause

Question 3

major anomaies

Answer 3

defects that require medical or surgical intervention

Question 4

minor anomalies

Answer 4

no serious medical or cosmetic significance

3 or more minor increase suspicion for major incidence

Question 5

normal variants

Answer 5

features that fall to far end of spectrum

Question 6

problems in morphogenesis

Answer 6

malformation
deformation
disruption

Question 7

malformation

Answer 7

abnormality of morphogenesis due to intrinsic problem within developing structure
due to altered tissue formation, growth or differnetiation due to genetic environmental or a combination of factors

Question 8

deformation

Answer 8

abnormality of morphogenesis due to extrinsic force on a normally developing or developed structure
mechanism-fetal constraint

Question 9

plagiocephaly

Answer 9

asymmetric head
occurs pre or post natal
corrected by helmets or positioning

Question 10

disruption

Answer 10

abnormality of morphogenesis due to destructive force acting upon the developing structure
mechanism-cell death or tissue destruction due to vascular, infectious or mechanical force

Question 11

vascular causes

Answer 11

aberrant vessels
vascular occlusion
hypoperfusion
vasoactive drugs

Question 12

porencephaly

Answer 12

vascular accident

occlusion of a cerebral artery may cause a porencephalic cyst

Question 13

poland anomaly

Answer 13

subclavian artery disruption
absent pectoral muscle defect
ipsilateral limb defect

Question 14

sequence

Answer 14

cascade of effects stemming from a single localized abnormality in early morphogenesis-single localized abnormality may be of malformation, deformation or disruption

Question 15

Shh

Answer 15

causes holoprosencephaly

Question 16

Robin sequence

Answer 16

micrognathia
abnormal tongue protrusion
U shaped cleft palate
possible airway obstruction

Question 17

Potter sequence

Answer 17

micrognathia
large ears typical
pulmonary hypoplasia
renal agenesis

Question 18

association

Answer 18

combination of anomalies which occur together more frequently than by chance alone
etiology is unknown
most cases sporadic

Question 19

CHARGE association

Answer 19

coloboma of eye
heart defects
atersia of choanne
retardation of growth and development
genital anomalies
ear anomalies

Question 20

VATER association

Answer 20

vertebral defects
imperforate anus
tracheo-esophageal fistula
rena lor radial ray defects

Question 21

MURCS association

Answer 21

mullerian duct, renal and cervical vertebral defects

Question 22

complex

Answer 22

anomalies of several different structures in same body region during embryogenesis

Question 23

OEIS complex

Answer 23

omphalocele
exstrophy
imperforate anus
spinal defects

Question 24

syndrome

Answer 24

multiple structural defects in one or more tissues thought to be due to particular chromosomal, genetic, teratogenic

Question 25

Cornealia de Lange syndrome

Answer 25

short stature mental retardation limb defects characteristic facies

Question 26

polymorphism

Answer 26

variant allele that is present in greater than one percent of the allelic population

Question 27

allelic heterogeneity

Answer 27

different alleles at the same locus (gene) which give rise to the same or similar disease

Question 28

dystrophin

Answer 28

required for assembly of synaptic junction

Question 29

Duchenne

Answer 29

out of frame deletions in DMD gene | no protein can be detected by IF

Question 30

Becker

Answer 30

in frame deletions | some protein detectable in myocytes by IF

Question 31

locus heterogeneity

Answer 31

genes at different loci that cause the same or similar disease

Question 32

PKU type I

Answer 32

defect in PAH | restrict phenylalanine and provide tyrosine

Question 33

PKU type II

Answer 33

defect in BH4 | restrict phenylalanine and provide LDOPA and 5HT

Question 34

PKU type III

Answer 34

defect in biopterin synthesis | restrict phenylalanine and provide LDOPA and 5HT

Question 35

mitochondrial genome

Answer 35

37 genes involved in ox-phos, rRNA and tRNAs

Question 36

heteroplasmy

Answer 36

mixture of mt genomes, some mutant and some wild type

Question 37

polygenic inheritance

Answer 37

two or more genes (gene products) interact to render the actual phenotype

Question 38

genetic phenomena from gene-gene interactions

Answer 38

sex influenced traits (AD) incomplete penetrance variable expressivity

Question 39

penetrance

Answer 39

probability of manifesting a trat given the presence of a defective allele either or phenomenon only in dominant modes of inheritance

Question 40

calculating percent penetrance

Answer 40

number with penotype/cases with genotype

Question 41

retinitis pigmentosa

Answer 41

heterozygous for both peripherin and ROM1 develop RP

Question 42

fragile x

Answer 42

moderate intellectual disability, large heads, large protruding ears, stubby hands, prominent jaw

Question 43

Sherman paradox

Answer 43

position in pedigree in part determines risk of developing the syndrome

Question 44

molecular basis Sherman paradox

Answer 44

FMR1-normal and premutation (50-200 repeats)

Question 45

location FMR1 mRNA

Answer 45

brain and testes | nucleocytoplasmic shuttling protein, role in postnatal brain development

Question 46

anticipation

Answer 46

apparent worsening of disease over several generations

Question 47

myotonic dystrophy

Answer 47

AD characterized by myotonia, ptosis, cataracts, hypogonadism, frontal balding, ECG changes trinucleotide repeat in 3' UTR protein kinase ch 19

Question 48

expressivity

Answer 48

type or degree of manifestation of a gene that is penetrant

Question 49

neurofibromatosis

Answer 49

AD | cafe au lait spots and benign neurofibromas

Question 50

uniparental disomy

Answer 50

gamete disomic for given chromosome will fertilize one which is nullisomic for same chromosome

Question 51

genetic imprinting

Answer 51

some genes are activated or inactivated in a sex specific manner

Question 52

prader wili

Answer 52

``` obesity, hyperphagia intellecutal disability hypogonadism small hands and feet only maternal 15q ```

Question 53

angelman

Answer 53

severe intellectual disability spasticity seizures only paternal 15q

Question 54

multifactorial inheritance

Answer 54

environmnetal and genetic factors combine to produce phenotype

Question 55

threshold human disease

Answer 55

NT defects cleft lip/palate cardiovascular disease A1AT and emphysema

Question 56

Alzheimer genetics

Answer 56

mutations in presenilins and APP lead to overproduction of Abeta peptide and early onset form of disease

Question 57

population genetics

Answer 57

study of distribution of alleles in populations and factors that maintain or alter allele frequencies

Question 58

Hardy Weinberg Law

Answer 58

genotypes will be distributed in a population based on allele frequencies genotype frequencies remain constant from generation to generation

Question 59

conditions Hardy Weinberg law

Answer 59

``` random mating large population negligible net mutation rate negligible amount of migration negligible amount of selection ```

Question 60

nonrandom matings

Answer 60

consanguineous matings matings in stratified population assortative mating (increase in homozygotes)

Question 61

genetic fitness

Answer 61

probability of transmitting gene to next generation

Question 62

founder effect

Answer 62

group do not have the same allele frequencies as their original population or the population they move into