Genetics Flashcards
name the defect:
carbamazepine
spina bifida
(esp early in pregnancy - days 15-29 after conception)
what may be present in fragile x carriers with premutation?
mild cognitive/behavioral deficits
premature ovarian failure
neurodegenerative disorder in older adults
(fragile x associated tremor/ataxia syndrome)
besides fragile x, what is another disease caused by a triplet repeat?
myotonic dystophy
autosomal dominant pattern
myotonia with progressive weakness and wasting
involvement of facial and jaw muscles
myotonia on grip testing
other involved organs: cataracts, testicular atrophy, diabetes, MR, premature frontal balding
congenital form
worse if inherited from mother
what findings are seen in NF2?
Bilateral eighth nerve masses seen with appropriate imaging techniques (e.g., CT, MRI)
or
A first-degree relative with NF-2 and a unilateral eighth nerve mass
or two of the following:
• Neurofibroma
• Meningioma
• Glioma
• Schwannoma
• Juvenile posterior subcapsular lens opacity
chromosome 22
also autosomal dominant
features of type 1 osteogenesis imperfecta?
blue sclera
rare fractures at birth, common in childhood
hearing loss
name the defect:
phenytoin
fetal hyadtoin syndrome
growth deficiency
devel delay
craniofacial anomalies
hypoplastic nails
vit K deficiency
congenital varicella
limb anomalies
chorioretinitis
skin scarring
devel delays
what syndrome includes:
jerky ataxic movements
fair hair
seizures
large chin
laughter
severe MR
angleman’s syndrome
deletion of maternal 15q11-13
“happy puppet”
klinefelter 47,XXY
meiotic nondisjunction
tall
gynecomastia
small testes
infertile
behavioral problems
NF1
cafe au lait spots
neurofibromas
axillary freckling
optic glioma
lisch nosdules (iris harmatomas)
learning disorders
60% are sporadic, but AD inheritance
name the defect:
retinoic acid
findings similar to digeorge
microcephaly
facial nerve palsies
microtia
ear anomalies
CV defects
thymic hypoplaisa
Gu anomalies
cornelia de lange
autosomal dominant
intrauterine growth retardation, persistent postnatal failure to thrive, moderate to severe cognitive impairment, and microcephaly with a flat occiput and low hairline. Facial features are quite distinctive and include long eyelashes; a fine, almost “brushed-on” appearance of the arch to the eyebrows; occasional synophrys due to hirsutism; small nose with anteverted nostrils; long philtrum; downturned upper lip with cupid’s-bow shape; and micrognathia
cri-du-chat 5p-
cat cry
moon face
wide spaced eyes
short stature
high palate
MR
heart defects in a 1/3rd
trisomy 18 (edwards)
IUGR
rocker bottom feet
clubfoot
clenched fist
overlapping fingers
VSD wtih dysplastic valves
more common in girls
treacher collins
mandibular and maxillary hypoplasia
zygomatic arch defects
ear malformations
colobomata
hearing loss
dislocated lens, high-arched palate, pectus, mitral valve prolapse?
marfan’s
autosomal dominant
aortic root dilation!
should avoid weight lifting
noonan syndrome
pulmonic stenosis
trisomy 13 (patau)
midline defects!
orofacial cleft
small eyes
postaxial polydactyly
holoprosencephaly
hypoplastic/absent ribs
gentical anomalies
cutis aplasia
what can be seen wtih tuberous sclerosis?
ash leaf spot (seen with woods lamp)
shagreen patch
infantile spasms
cardiac rhabdomyoma
polycystic kidney disease
autosomal dominant
what type of OI causes death at birth?
type 2, very severe
respiratory failure
multiple fractures
name the defect:
thalidomide
limb malformations
deafness
what is mode of inheritance?
xlinked recessive
clues:
- only females can transmit to sons
- if generation has only females, will have appeared to have skipped that generation
- affected father transmits disease allele to all daughters
- carrier females have 50% chance of passing on to sons
achondroplasia
shorter proximal than distal parts of extremities
trident hands
macrocephaly
flat nasal bridge, prominent forehead, midface hypoplasia
autosomal dominant - usually new mutation however
increases with advanced paternal age
can have compression of cervical cord
name the defect:
streptomycin
hearing loss
what syndrome includes:
hypotonia at birth
obesity
short stature
small hands and feet
hypogonadism
prader-willi
deletion of paternal 15q11-13
what is WAGR syndrome
Wilm’s tumor
Aniridia
GU malformations
Retardation (MR)
11p13- deletion
what are the classic skin findings in ehlers-danlos?
hyperextensible skin
extra skin
texture of wet sponge/chamois
fragile, tears easily
thin shiny scars
increased brusing
mitral valve prolapse is common
name the defect:
warfarin
nasal hypoplasia
stillpled epiphyses
what is the most common presentation of van hippel-lindau?
cerebellar hemangioma in adolescence
retinal hemangioma before age 10
what other disorder do you need to rule out in someone you think has marfans?
homocystinuria
what causes this condition?
what other abnormailties may be present?
fragile x (xlinked-ish)
CGG repeat
MR
large head
long face, large ears
large hands/feet
large testes
hyperextensible joints
turner syndrome
45,X
short stature
ovarian failure
lack of secondary sex characteristics
aortic vavle/coarct
thyroiditis
fetal alcohol syndrome
what tumors are commonly seen in patients wiht von hippel-lindau syndrome?
hemangiomas (cerebellum, retina)
pheo
endolymphatic sac tumors
kidney/pancreas cysts
renal cell carcinoma
neuroendocrine tumors
pancreatic tumors
what main things make up hemifacial microsomia?
ear abnormalities with maxillary or mandibular hypoplasia
can also have cardiac or vertebral abnormalities
goldenhar syndrome: above plus fatty masses on the globes
Alagille syndrome (20p12-)
AD inheritance
bile duct paucity with cholestasis
pulmonary valve stenosis
peripheral artery stenosis
triangle chin
what is the mode of inheritance?
autosomal recessive
clues:
- disorder in sibs but no other generations
- males and females equally affected
- males and females can pass it on
- risk of 2 heterozygotes to have affected is 1/4
- consanguinity increases risk of affected child
which type of OI has the greatest risk of neurologic complications?
type 3
numberous fractures at birth
usually cant bear weight
name the defect:
lithium
ebstein anomaly
(before 8 weeks gestation)
apert syndrome
Brachycephaly due to coronal suture synostosis
Midface hypoplasia
Choanal stenosis
Cleft palate
Conductive hearing deficits
Symmetrical syndactyly of the hands
Cervical spine fusion
Cardiovascular anomalies
Hydronephrosis
Cryptorchidism
22q11.2-
DiGeorge / velocardiofacial / CATCH22
cleft palate
absent thymus
tet of fallot / interrupted aortic arch / vsd
hypoparathyroidism
immune deficiency
hypocalcemia
Williams syndrome
7q11.23 deletion
friendly personality
supravalvular AS
stellate pattern of the iris
down-turned lower lip
hypercalcemia
wolf-hirschorn syndrome
4p-
“greek helmet” facies - hypertelorism, prominent glabella, frontal bossing
beaked nose
hypotonia
heart defects
seizures
name the defect:
valproic acid
spina bifida
craniofacial anomalies
preaxial defects
congenital rubella
up to 8 weeks: deafness
9-12 weeks: cataracts
12-30 weeks; heart defects
name the defect:
diethylstilbestrol
vaginal adenocarcinoma in the offspring of the fetus at a later age
crouzon syndrome
Brachycephaly due to coronal suture synostosis
Hydrocephaly with Chiari I malformation
Hypertelorism
Proptosis
Midface hypoplasia
“Beaked” nose
Cleft palate
Stylohyoid calcification
Conduction and/or neurosensory hearing deficit
Cervical spine fusion
Acanthosis nigricans
what findings on maternal screen during pregnancy are indicators of down syndrome?
low AFP
low estriol
elevated hCG
elevated inhibin
name the defect:
methotrexate
craniosynostosis
limb defects
craniofacial abnormalities
esp b/w weeks 6-9 of gestation
features of OI type 4?
white sclera
milder form like type 1
tibial bowing!
if you have a child with ear malformations, what else should you look for?
renal malformations
also consider other midline defects
name the defect:
tetracycline
bone and tooth staining
what is the mode of inheritance?
autosomal dominant
clues:
- both sexes are equally affected
- both sexes can transmit to offspring
- no generation is skipped
- every affected child has an affected parent
- you see father to son transmission
how is the ear displaced in positional plagiocephaly?
anterior displacement of ear and frontal prominence on the same side as the flattening (everything pushed forward)
