13 - Neurogenetic d/o in kids Flashcards
juvenile huntington’s is more likely to be inherited from which parent?
father - more likely for allele to expand in spermatogenesis
pathophys of huntingtons
triplet repeat > more glutamine residues > protein acts differently
gain of function mutation
assoc sx in myotonic dystrophy
cataracts, cardiac conduction abnlty
presentation of congenital myotonic dystrophy
hypotonia and severe generalized weakness at birth, often w/ resp insufficiency and early death
MR common
myotonic dystrophy allele is more likely to expand from what parent?
mother
pathophys of myotonic dystrophy
repeat expands the mRNA > more RNA binding proteins on it > interferes w/ production of other proteins
how is fragile x dx?
DNA analysis
effects of premutation in fragile x
in males - tremor ataxia
in women - primary ovarian insufficiency earlier in life than normal
pathophys of fragile x
repeat causes hypermethylation > loss of function mutation
cause of Rett syndrome
mutation in MECP2 (on x chromosome)
epigenetic effect - dec transcription of other genes
Rett syndrome mutation in boys
severe neonatal encephalopathy, manic depressive psychosis, pyramidal signs, parkinsonism, macroorchidism
SMA - pathophys
degeneration and loss of anterior horn cells and cranial nuclei
SMA - genetics, course
AR - SMN1
symmetrical proximal muscle weakness and atrophy, progresses
SMA type 1 - other name, presentation/course
Werdnig Hoffman
onset 0-6 mo, frog leg posture, lack of motor development, never achieve ability to sit w/o support**, tongue fasciculation, no DTRs, paradoxical breathing
normal sensation and cognitive fn
fatal by 2 yo w/o intervention
Tay sachs - what is wrong, normal course
hexosaminidase A def (lysosomal storage d/o), abnl storage of gangliosides (sphingoglycolipids in membrane)
nl at birth, onset in first few mo (hypotonia), progressive deterioration, death by 2-4 yrs
