Gen and Cong Abnormalities

Question 1

mendelian disorder

Answer 1

single gene mutations

Question 2

AD disorders

Answer 2

affects non-enzyme proteins

affects key structural proteins

Question 3

AR disorder

Answer 3

largest category of mendelian disorders
expression more uniform
complete penetrance common
loss of function of enzyme protein
inborn errors of metab

Question 4

X-linked disorders

Answer 4

recessive (almost all)

dominant –> Vit D -resistant rickets

Question 5

Galactosemia

Answer 5

accumulation of substrate

Question 6

Albinism

Answer 6

enzyme defect leading to metabolic block –> dec amount of end product

Question 7

alpha-1-antitrypsin def

Answer 7

failure to inactivate tissue-damaging substrate

Question 8

Familial Hypercholesterolemia

Answer 8

reduced synthesis or function of LDL receptors

most frequent mendelian disorder

Question 9

Cystic fibrosis

Answer 9

defective system for Cl- xsport

Question 10

Sickle cell disease

Answer 10

alter nonenzyme protein structure

Question 11

Thalassemia

Answer 11

mutation in globin genes affect amount of globin chains synth

Question 12

Osteogenesis imperfecta

Answer 12

collagen structural defect

Question 13

Muscular dystrophy

Answer 13

Dystrophin structural defect

Question 14

hereditary spherocytosis

Answer 14

spectrin structural defect

Question 15

G6PD deficiency

Answer 15

gen determined adverse reaction to drugs (fava beans)

Question 16

Marfan syndrome

Answer 16

fibrillin defect

arachnodactyly / lax joints / lens dislocation / mitral valve prolapse / aortic dissection and dilation

Question 17

Ehlers-Danlos Syndrome

Answer 17

disorders of defective collagen synthesis or structure
hyper extensible skin / hyper mobile joints / colon rupture / artery rupture, etc
14 types

Question 18

Tay-Sachs Disease

Answer 18

GM2 gangliosidosis
Hexosaminidase A deficiency
ganglioside accumulation in tissues
chromosome 15
Oil red O stain 
cherry red spot in macula

Question 19

Neimann-Pick Disease

Answer 19

accumulation of sphingomyelin
sphingomyelinase def
Type A most common --> severe infantile form
lipid laden foam cells
cherry red spot

Question 20

most common lysosomal storage disease

Answer 20

Gaucher disease

Question 21

Gaucher disease

Answer 21

most common lysosomal storage disease
glucocerebrosidase gene mutation
glucocerebroside accumulation in phagocytes –> Gaucher cells –> crumpled tissue paper (fibrillary cyto)
PAS+

Question 22

Type I Gaucher disease

Answer 22

most common
limited to phagocytes throughout the body
spares CNS

Question 23

Type II Gaucher disease

Answer 23

infantile acute cerebral pattern
die early
no predilection for Jews

Question 24

Mucopolysaccharidoses

Answer 24

types I-IV
all are AR except Hunter (XR)
coarse facial features / cloudy cornea / stiff joints / mental retardation

Question 25

Alkaptonuria (Ochronosis)

Answer 25

``` homogentisic oxidase def accumulation of homogentisic acid black urine upon standing black/blue discoloration of tissues degenerative arthropathy --> cart becomes brittle and fibrillated ```

Question 26

neurofibromatosis type I

Answer 26

neurofibromas cafe au lair spots lisch nodules --> pigmented iris hamartomas mutation NF-1 gene --> codes for neurofibromin (tumor suppressor gene)

Question 27

neurofibromatosis type II

Answer 27

bilateral acoustic schwannomas multiple meningiomas NF-2 gene --> also tumor suppressor

Question 28

Tuberous Sclerosis

Answer 28

AD CNS hamartomas --> cortical tubers and subependymal nodules other tumors cutaneous lesions (ash-leaf patches and such) TSC1 = hamartin mutation TSC2 (more common) = tuber in mutation proteins forms complex inhib the kinase mTOR lots of cyto; giant cell astrocytomas in CNS and cardiac rhabdomyomas

Question 29

Trisomy 21

Answer 29

``` Down Syndrome most common chromosomal disorder d/t meiotic disjunction maternal age strong influence simian crease / brushfield spots on iris / etc ```

Question 30

Trisomy 18

Answer 30

``` Edwards syndrome overlapping fingers micrognathia low set ears rarely live more than a few years ```

Question 31

Trisomy 13

Answer 31

Patau syndrome cleft lip and palate rocker-bottom feet rarely live more than a few years

Question 32

Principle cause of reduced spermatogenesis and male infertility

Answer 32

Klinefelter syndrome | XXY

Question 33

most common sex abnormality in females

Answer 33

Turner syndrome XO cystic hygroma

Question 34

Rubella

Answer 34

at risk first 16 wks PDA microcephaly cataracts

Question 35

most common fetal viral infection

Answer 35

CMV highest risk period is second trimester owl eye inclusions