Child Neuro / Genetic disorders Flashcards
anencephaly is due to what brain defect and when does it occur?
24 days gestation, failure of anterior neural tube closure
What visual function is present at birth?
black/white vision
myeloschisis is what, when does it occur?
failure of posterior neural tube closure. Neural structures protrude and expose spinal cord
encephalocele is due to what problem, what is the defect?
failure of anterior neural tube closure; intracranial contents herniate through midline skull defect
what lab test might be elevated in encephalocele?
elevated alpha-fetoprotein
What syndromes may have encephalocele?
Meckel-Gruber syndrome
What is Meckel’s syndromle?
Microcephaly Encephalocele Cleft lip Kidneys polycystic Eyes small: microphthalmia Lots of fingers: polydactyly Sex ambiguous
Difference bewteen myeloschisis and myelomeningocele
membrane covering in myelomeningocele
Def of arnold chiari type 1
cerebellar tonsillar displacement: 5mm through foramen magnum
Define type 2 Chiari malformation?
cerebellar tonsil displaced
medulla inferiorly displaced (may be kinked)
lumbosacral myelomeningocele
beaked tectum
Chiari III malformation?
Type II + occipital encephalocele
Type IV chiari?
Cerebellar hypoplasia
secondary neurulation refers to what?
formation of caudal neural tube w/ lower sacral and coccygeal segments - causes dyraphic states; abnl filum and conus
Caudal Regression Syndrome?
Who is at risk?
malformations of caudal region: hindgut, GU, caudal spine, spinal cord and lower limbs
Infants of diabetic mothers
dastematomyelia
bifid spinal cord (septum divides sc longitudinally)
Myelocystocele
Associations?
dilation of central canal of caudal neural tube
GI or GU anomalies (bladder/cloacal extrophy, imperforate anus, omphalocele)
Schizencephaly is a disorder of what developmental issue?
segmentation
schizencephaly gene mutation?
EMX2 on Ch10q26.1
Holoprosencephaly defects? (3 types)
Type of disorder
prosencelphalic cleavage disorder
Causes olfactory bulb/tract absence, midline facial defects, cyclopia, organ malformations.
1. Alobar: most severe: single ventricle, no separation of hemispheres, absent CC, fused thal/BG
2. Semilobar: posterior hemisphere separation, splenium cc present
3. Lobar: absent septum pellucidum, incomplete formation of interhemispheric fissure and cerebral falx
possible gene for holoprosencephaly
sonic hedgehog on 7q36
What is aicardi syndrome? (triad and genetics)
X-linked dominant
- agenesis of corpus callosum
- infantile spasms
- chorioretinal lacunae
Septo-optic dysplasia characterized by what?
Genetics?
optic nerve hypoplasia, absence of septum pellucidum, hypopit (may have hypothal)
SOD: 3 letters, Chrom 3 (HESX on 3p21)
Miller-Dieker syndrome characteristics and genetics
lissencephaly, microcephaly, sz, craniofacial, cardiac
Genetics: 17p13.3 deletion (includes LIS1 gene and 14-3-3)
DCX gene on chr xq22 in isolated lissencephaly presents in m/f?
Encodes for what?
Males: lissencephaly,
females (heterozygous): subcortical band heterotopia
Double cortin (double standards in M/F)
Lissencephaly more severe anteriorly vs posteriorly (gene)
anteriorly: DCX mutation
posteriorly: LIS1 mutation
4 diseases on chromosome 17:
- NF1
- Alexander’s Disease
- Canavan’s Disease
- Miller Dieker syndrome
Gene for lissencephaly with absence of corpus callosum and what is the presentation?
ARX on Xp22.13:
lissencephaly, absence of CC, sz, hypothalamic issues (hypothermia), ambiguous genitalia
(Are you XX or XY: ARX)
Gene with lissencephaly and cerebellar hypoplasia
RELN at 7q22 (Reelin)
Reelin from unsteadiness
3 diseases with cobblestone lissencephaly
- syndromic congenital dystrophies : no cortical recognizable layers
1. Fukuyama
2. Muscle-eye-brain disease
3. Walker Warburg syndrome
Genetics of Walker warburg?
mutation in POMT1 on chr 9q34
GEnetic cause of periventricular nodular heterotopia, genetics?
FIL-1 xq28 encodes filamin-1, usually female (males lethal)
*mutations in FIL-1 cause heterotopic neurons to FILL the ventricle
oculomotor apraxia, hyperpnea alternating with central apnea in neonates, cerebellar vermis agenesis
Dx and characteristic finding?
Joubert syndrome. Midbrain/hindbrain junction looks like molar tooth
pontocerebellar hypoplasia, inverted nipples, abnormal fat pads?
Dx
Congenital disorder of glycosylation Ia
Genetics of familial hemiplegic migraine
CACNA1A voltage-dep P/Q type calcium channel 1A gene on Chr 19p13
Three diseases with CACNA1A mutation on chr 19p13
Familial Hemiplegic migraine 1
Episodic ataxia-2
Spinocerebellar ataxia 6
Mutation in Familial hemiplegic migraine 2
ATP1A2 gene on chr 1
TORCH infx?
Toxo, Rubella, CMV, HSV
Cayler syndrome?
aka cardiofacial: hypoplasia of depressor anguli oris: asymm crying faces. Think Cardiac too
Duane syndrome?
absence or hypoplasia of abducens nucleus and nerve w/ aberrant innervation of LR by CN3
What is mobius syndrome?
Congenital facial diplegia w/ abducens palsy and +/- NM abnormalities
Vein of galen malformation is actually what dilated?
median prosencephalic vein of Markowsky dilation
What is Masa syndrome? Genetics?
X-linked recessive, L1CAM gene
MR, Aphasia, Shuffling gait, Adducted thumbs
(aqueductal stensois, agenesis of cc
CRASH Syndromes?
CC hypoplasia, mR, Adducted thumbs, Spastic paraparesis, Hydrocephalus
-all X-linked recessive L1CAM w/ hydroceph, Spast paraparesis 1, CC agenesis, MASA
(better for MASA than NASA to CRASH a CAMaro)
Dandy Walker syndrome? (triad)
associated sx?
Agenesis of cerebellar vermis
Cystic dilation of 4th V
Enlarged posterior fossa w/ elevated tentorium
May be assoc w/ occipital encephalocele, DD, cortical malf, sz, polycystic kidneys, cardiac
PHACES?
Posterior fossa malformation Hemangiomas of FACE Arterial anomalies Coarct Ao Eye abnl Sternal clefting / supraumbilical raphe
Draw sutures and types of craniosynostosis
- Coronal: gives brachycephaly
- Metopic gives trigonocephaly
- sagittal gives scaphocephaly/dolichocephaly
- lambdoid gives posterior displaced ear (trapezoid)
- deformational gives anterior placed ear (parallelogram)
Apert syndrome?
Genetics / inheritance
coronal craniosynostosis, syndactyly, proptosis, hypertelorism
(Can’t get fingers apart)
FGFR2 on 10q26, AD
Carpenter disease and inheritance
multiple suture abnl causing clover leaf deformity, polydactyly (lets carpenter hold tools), MR
AR
Crouzon’s
-dz and geneticas
craniofacial dysostosis: beaklike nose, maxillary hypoplasia, but NO syndactyly unlike Aperts
Same genetics: AD, FGFR2 on 10q26