2-2 Biochemistry

q123456's version from 2016-06-01 16:50


Question Answer
I-Cell Diseasefailure of addition of Mannose-6-Phosphate to proteins >>>lysosomes
Osteogenesis imperfect
problems FORMING triple helix of type I collagen
Multiple fractures w/ minimal trauma,
blue sclerae,
hearing loss,
dental imperfections
Ehlers-Danlos SyndromeAR
Type III collagen
defect in lysyl hydroxylase (vit C as a cofactor)
hyperextensible skin, hypermobile joints, easy bruising***like vit c def >>>scurvy
Alport Syndromeabnormal type IV collagen
progressive hereditary nephritis/deafness/ocular disturbances (lenticonus)
goodpaste: Ab against collagen IV
von Hippel-Lindau diseaseVHL gene (on chromosome 3), constitutive expression of HIF transcription factor
Huntington's DiseaseAD, CAG, chr 4
depre, dementia, choreiform move
degeneration of the striatum (caudate and putamen
ventricles are dilated and atrophy of the caudate nucleus
Fragile X SyndromeCGG
FMR1 gene
X-linked dominant like
anticipation and x inactivation
Familial Adenomatous PolyposisAPC gene
chr 5
Cri-du-chat Syndromechr 5
mental retardation, high-pitched crying/mewing
Prader-Willi SyndromePaternal chr15
Angelman's SyndromeMaternal chr15
inappropriate laughter (Happy Puppet Syndrome)
Autosomal-Dominant Polycystic Kidney Disease (ADPKD)PKD1
Williams Syndromechr 7 (Cystic fibrosis: chr 7)
distinctive "elfin" facies, hypercalcemia (inc. sensitivity to Vit D), well-developed verbal skills, extreme friendliness with strangers
neuroblastoma<5 year old
palpable abdominal masses
arise from neural creast cells
adrenal meddula is the most common site
homer wright pseudorosettes (circles of tumor cells with central young nerve fibers)
Wilm tumor
Neurofibromatosis type 1 (von Recklinghausen's Disease)KA31-19
AD, mutations in neurofibromin.
Neurofibromin: negative regulator of RAS. Disruption of neurofibromin >>>RAS hyperactivity
Cafe-au-lait spots ***seen in McCune-Albright syndrome
neural tumors, lisch nodules (pigmented iris hamartomas) KA33-41
Human merlin is coded by the gene NF2
chr 22

bilateral vestibular schwannomas(acoustic neurom)
CNVIII>>> unilateral (one-sided) or asymmetric hearing loss
tinnitus (ringing in the dizziness/loss of balance)
a benign, usually slow-growing tumor that develops from the balance and hearing nerves supplying the inner ear.
Tuberous SclerosisHamartin or Tuberin gene mutation
Hamartomatous (not hemangioblastoma) KA33-41
X ChoromsoneKlinefelter syndrome
the most common cause of male sterility.
male, tall, small firm testes, infertility
testicular Seminiferous tubules atrophy and replaced by pink and hyalinized tissue>>>decreased inhibin/small testes>>>low testosterone>>>high FSH/elevated estradiol/erectile dysfunciton
Non disjunction of the sex chromosomes during meiotic division 47xxy
***Kartagener's Syndrome

Turner and Klinefelter syndrome, both are infertility, Turner is short, Klinefelter is tall.
43% Turner syndrome>>>normal appearance but primary amenorrhea: mosaics or have structural abnormalities of the X chromosome
Streak ovaries, infertility, amenorrhea
medium chain acyl-CoA dehydrogenase (MCAD)
Tuberous Sclerosis (patients has polycystic kidney)Facial lesions (adenoma sebaceum),
hypopigmented "ash leaf spots" on skin,
cortical & retinal hamartomas,
seizures, mental retardation,
renal cysts and renal angiomyolipomas,
cardiac rhabdomyomas
von Hippel-Lindau diseaseVHL chr 3
hemangioblastomas of retina/cerebellum/medulla,
bilateral renal cell carcinomas,

LYNCH: colon+endometrial+ovarian
Li Fraumeni: TP53 (17p)>>> sarcomas+breast+brain+adrenal cortex+leukemia
MENII: RET protooncogene.
Fragile X SyndromeMacroorchidism, large face/jaw/ears, autism, mitral valve prolapse
mental retardation:
***the most common known cause of mental retardation is fetal alcohol syndrome
***genetic causes are fragile x syndrome and down syndrome.
congenital microdeletioncri-du-chat syndrome (Chr 5) and Williams syndrome (Chr 7)
AchondroplasiaFGF receptor 3
dwarfism (short limbs, large head, normal trunk size)
Familial dyslipidemias1) Hyperchylomicronemia
type I
lipoprotein lipase deficiency
apolipoprotein CII (KA35-46) *B48 binds to chylomicrons, CII turns on lipoprotein lipase

2) Familial Hypercholesterolemia
type IIA
defective or absent LDL receptor
KA31-10, KA32-45
Elevated LDL, Tendon Xanthomas, MI before age 20

3) Hypertriglyceridemia
type IV
Hepatic overproduction of VLDL
Hereditary SpherocytosisSpectrin or Ankyrin
Hemolytic anemia, increased MCHC, RBC lysis on Osmotic Fragility Test
Marfan's Syndrome----------------------
Fribrillin-1 gene mutation
AD, Normal IQ, tall, long extremities, hypermobile joints,aortic root dilation, upward lens dislocation
***homocystinuria: AR, Low IQ, cystathionine synthase deficiency or decreased affinity of enzyme for pyridoxal phosphate .Thrombosis, downward lens dislocation, mega anemia
Edwards' Syndromesmall jaw/ears, clenched hands
Patau's Syndromecleft lip/palate
down syndromesimian crease, duodenal atresia, congential heart disease (ASD)
Triplicate copy of the amyloid precursor protein (APP) gene on chr21.
*Robertsonian translocation
*Down mosaicism
hereditary hemorrhagic telangiectasiaSTKII gene
inherited disorder for blood vessels
peutz-jeghers syndrome: small dark sports on the lips in children
recurrent epistaxis
ateriovenous malformations (AVMs)>>>severe headache and nausea and vomiting>>>subarachnoid hemorrhage
heart failure
*Arteriovenous malformation (AVM) is an abnormal connection between arteries and veins, bypassing the capillary system.

2rd polycythemia>>>high Epo due to chronic hypoxemia from right to left shunt
rion deficiency anemia due to bleeding