Genetic disorders and inborn errors of metabolism Flashcards
genomic imprinting
expressed solely based on sex of parent passing on defective gene ~ 11q of 15 -> angel man or trader-willi
maternal markers
alpha feto protein- incr with neural tube defects, multi gestation, fetal demise, underestimated gestational age, ventral abd wall defects
triple marker: nAFP, unconguated estriol, beta-HCG. down= low AFP, low estriol, high beta-hcg. all 3 low= trisomy 18
cvs
10-13wks. kayotype, DHA extration, enzym eanalysis
amniocentesis
16-18wks. sloughed fetal cells.
percutaneous umbilical blood sampling
hematologic abn, genetic d, infection, fetal acidosis. used to arm med or blood transufsion to fetus
common genetic D
marfan syndrome, prader willi, angelman, noonan, digeorge,ehler danlos, osteogenesis imperfecta, VACTERL association, CHARGE, Williams, Cornelia de Lange, Russell silver syndrome, pierre robin syndrome, cri du chat syndrome,
marfan syndrome
AD. CT D. C15-fibrillin
affect: ocular, CV, skeletal
P: tall, elongated extremitis/ fingers, j laxity, chest wall deformities (pectus excavatum), scoliosis or kyphosis. decr upper to lower segment ratio. upward lens subluxation and retinal detachemnt (need regulr ophthalmologic exam), aortic root diation, aortic dissection. aortic regurg
Dx: clinical. need r/o homocystinuria
C: endocarditis (prophylax), sudden death-dissection, HTN,
prader willi
P: almond eyes, fish like mouth. FFT, short, small feet. hypotonia, MR, hypogonadism
Dx: FISH
C: hypotonia- poor sucking. obesity- obstructive sleep apnea, cardiac disease, DM2, psych
angelman
C: jerky arm mV, ataxia. small wide head, large mouth, prognathic, blood hair blue eyes
noonan syndrome
= male turner. AD. C12
P: short, shield chest. short webbed neck and low hairline. right sided heart lesion~ pul valve stensis (turner has left sided heart lesion), MR in 25%
Dx: clinical
DiGeorge and celocardiofacial syndrome
AD or sporadic. C22q11 deletion. CATCH-22
Cardiac anomaly, abn facies, thymic hypoplasia, cleft palate, hypocalcemia (sz), C22.
digeorge: short palpebral issues, chin/ear anomalies, to, VSD, AA anomalies,
vekicaruifacuak: cleft palate, promiennt nose with square nasal root, fish mouth, short chin, VSD, right sided AA, hypotonia, learning D, preservative behavior.
Dx: FISH
ehlers-Danlos sydnrome
AD. defective type V collagen
Phyperextensible J -dislocation and scoliosis, loos/fragile skin (minor laceration = major wounds that heal poorly with broad atrophic tissue paper thin scars), MV prolapse, aortic root dilation, fragile vessels= bruise easily, constipation, real proposal hernia
dx- clinical
C: aortic dissection, GI bleeding
osteogenesis imperfecta
abn type I collagen
P: blue sclerae, fragile bones, yellow or gray-blue teeth, easy bruisability
dx: clinical and decr tpye I syn in fibroblast
C: early conductive hearing loss, skeletal deformity 2/2 fractures
VACTERL association
vertebral defects, anal atresia, cardiac anomalis -VSD, TE (tracheoesophageal fistula), renal, limb defects (hypoplasia, syndactyly),
dx- clinical
CHARGE
sporatic colobomas, heart defect-tog,, atresia of nasal choanae, retardation, genial anomalies, ear
williams
AD. C7- elastin.
P: cocktail party personality. elfin facies, MR, loquacious, supravalvular aortic stenosis, idiopathic hypercalcemia in infancy, CT abn- hoarse voice, hernia
dx- FISH
Cornelia de lange
sporatic> AD
P: single eyebrows (cynophrys), short, no skeletal abn, SGA. FFT, microcephaly, downturn upper lip, micrognathia, infantile hypertonia, MR, small hands/ft, cardiac defect, autistic behavior, no expression, self destructive
dx-clinical
Russell silver syndrome
short, skeet asylum, normocephalic, SGA
pierre robin syndrome
micrognathia, cleft lip and palate,
dx clinical
C: recurrent otitis media, upper airway obstruction
cri du chat syndrome
C5-arm delation. sporadc
catlike cry, microcephaly, MR.
dx-deletion, clincal
down syndrome
epicentral skin folds, brachycephaly, protruding tongue, hypotonia, clinodatyly, wide space btw 1st and 2nd tow, duodenal atresia, hischsprong, pyloric stenosis, cardiac-40%
C: atlantoaxial cervial spine instbaility, leukemia, celiac, alzheimer, obstructive sleep apnea, hearing loss, hypothyroidism, cataracts, glaucoma, refractive error
trisomy 18
F>M
MR, hypertonia, scissoring of LE, delicate small facial features, clenched hands, overlapping digits, rocker botton feet
95% die