Genetic disorders Flashcards
chromosomal disorder
abnormal number - aneuplodiy (trisomy, monsomy)
abnormal structure - translocation, inversion, ring chromosome, deletions
Autosomal dominant
one, non-sex chromosome
only one gene mutated
vertical transmission (generational)
ex: Huntington dz, neruofibromatosis
Autosomal rescessive
two genes of non-sex chromosome mutated
horizontal transmission (siblings)
ex: CF, sickle cell
X-linked dominate
gene on X chromosome
lethal in males
no father - son transmission
ex: Rett syndrome
X-linked recessive
gene on X chromosome
males mostly, female carrier
Ex: Turner - female
Ex: Hemophila, Duchenne MD - male
Imprinting
regulates expression of derived genetic materal -
exclusive expression of maternal gene -> paternal gene is imprinted (silenced)
Mitochondria
inherited maternally via egg
organelles of energy - disorders involve multiple organ systems
Multifactorial
interaction btw genetic/environmental issues
Most common form of birth defects
Ex: cleft lip, asthma, congenital heart disease, DM, club foot, spina bifida
Fragile X - Eti
x-linked
common cognitive disabilty in males d/t repeat CGG in FMR1 gene
Fragile X - Sx
intellectual disabilities, oblong face, large ears, high voice, large tesicles post puberty
autistic-like behavior
Fragile X - Comp.
recurrent infxn, seizure, autism disorders
Fragile X - Prog
intellectual disability dependant - Valproic acid help with ADD
Klinefelter - Eti
XXY - boys with extra X
Klinefelter- Sx
hypogonadotropic hypogonadism, small testes, microorchidism, lack libido/potency, minimal facial hair, tall/eunuchoid build (reduced/indeterminate sexual characteristics)
varible IQ - progressive disabilites, Dx made post puberty
Klinefelter - Comp
intellectual disabilities, infertility
Klinefelter - Prog
full active lives - manage w/ testosterone therapy
Down Syndrome - Trisomy 21 - Eti
3 copies of chromosome 21
@risk with increased maternal age, dx in 1st or 2nd trimester w/ nuchal thickening, underdeveloped nasal bone, screen w/ alpha-fetoprotein
Down Syndrome - Sx
hypotonia, poor Moro reflex, hypermobility of joints, flattend facies/occiput, excessive skin on neck, anomalous auricles, upwar-slanting palpebral fissures, pelvic dysplasia, dysplasia of middle phalanx of fifth finger, single transverse palmar crease
Down Syndrome - Comp
congential heart disease - atrioventrical septal defects
Down Syndrome - Prog
a-okay - live, work and play just like the rest of us with some extra health concerns
Trisomy 18 - Eti
male:femal 1:3
Trisomy 18 - Sx
small for gestational age, low birth weight, dysmorphic facies and extremities - overlapping finders, rocker bottom feet
Trisomy 18 - Comp
heart disease - VSD pr patent ductus arteriosus, congnitive disabilities
Trisomy 18 - Prog
death d/t heart failure or PNA early in life
