disorders of block 2
Terms
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- Abnormal vertebral regionalization:
-
-Kioppel-Fiel anomaly
Sacralized/lumbarized vertebrae - Kioppel Fiel
-
fusion of cervical vertebrae
short neck
low nuchal hair line - sacralized/lumbarized vertebrae
- change in TYPE not NUMBER
- Assymetry of vertebrae:
-
-scoliosis
-lordosis
-kyphosis - Failure of Fusion of neural arches of vertebrae:
- Dysraphism
- Types of dysraphism
-
rachiscisis - many open
spina bifida - one or a few -
mildest spina bifida
worst spina bifida -
mildest = occulta
orst = aparta - spinal cord exposed - amniotic fluid - Formation defects of vertebrae:
-
hemivertebrae
wedge-shaped
unsegmented bars - Rib/spine defects
-
-accessory/fused (lumbar in males most common)
-Malformed sternum/costal cartilage
-Forked ribs - Dysraphic skull frmation:
- Acrania
- Suture defects 4
-
Craniosynostosis
Craniofacial dysostosis
Cloverleaf skull
Aperts - Craniosynostosis
-
sutures close prematurely
defect of FGF receptors 1/2 - Craniofacial dysostosis
- all sutures involved
- cloverleaf skull
- 85% of all cases have additional abnormalities
- Aperts
- large calvaria, acrocephalosyndactyly
- Microcephaly
-
-Genetic and environmental
-Normal sz face, small calvaria
-brain defects - Craniovertebral junction
-
Bone fusion or loose ligaments
short neck, low nuchal hairline, restricted head/neck movement - pectoral girdle abnormalities
-
-cleidocranial dysplasia
-sprengel anomaly - Cleidocranial dysplasia
-
Hypoplasia, aplasia of clavicles
large head, small face
long/narrow neck
shoulders droop
Delayed fontanelle closure
Incompete pubic development - Sprengel anomaly
-
Scapula at C4-T2
Hypoplastic
Usually left, maybe bilateral - Chondrodystrophias
-
Group of disorders characterized by disproportionate growth
-no mental feature - Achondroplasia
-
interference with epiphyseal plate development
-Short extremities
-Short stature
-Normal trunk
-Big cranium
-Small face
Normal intelligence - Mutation causing achondroplasia:
- FGF receptor 3 gene
- Marfan's syndrome
-
Defective fibrillin production
Autosomal dominant
long digits, aortic aneurysm
eye/spine abnormalities
joint hypermobility - Mucopolysaccharidoses
-
Lysosomal storage disorder
autosomal RECESSIVE
deterioration w/ face and skull distortion - Osteogenesis imperfecta
-
multiple fractures
Type I collagen defect - Endocrine disorders of skeletal development
-
-Hyperpituitarism
-Hypothyroidism - Hyperpituitarism
-
OVerproduction of GH
-Gigantism (prepuberty)
-Acromegaly (postpuberty) - Hypothyroidism
-
MENTAL
skeleta/ear anomalies
-bone age is younger than should be - Muscular malformations - absent
-
-Absence of sternocostal head of pec major - most common to miss
-Prune belly syndrome - urinary bladder defects - Congenital torticollis
-
wryneck
-Fixed rotation/tilt of head
-Trauma during birth - Family of genetic diseases exhibiting progressive deterioration of skeletal muscle but w/o CNS and peripheral nervous pathology:
- muscular dystrophy
-
most common type of MD:
-inheritance
-abnormality -
duchennes
-X-linked recessive
-Muscles lack dystrophin - susceptible to dmg when stressed -
Deaths caused by Congenital nervous system malformities:
-Fetal
-Infant -
Fetal = 75%
Infant = 40% - % of all abnormalities:
- 10
- % of affected embryos aborted during wks 4-8:
- 90
- Neural tube defects - Dysraphic errors result from
- Error in primary neurulation
- When primary neurulation occurs:
- weeks 3-4
- Characteristics of dysraphic errors:
-
-Faulty NT closure
-Dorsal location
-Midline defects - Supplment that helps prevent dysraphic errors:
- -maternal folic acid
- Most severe dysraphic error in neural tube devo:
- MeroAnencephaly
- Meroanencephaly - 3 symptoms
-
-Calvaria missing
-Vascular forebrain/midbrain tissue mass
-High AFP levels diagnostic - Encephalomeningocoele
-
skull defect
brain/meninges herniated - cranial meningocoele
- only meninges herniated - filled with CSF
- cranium bifidum
-
Skull defect
May/may not be brain or meningeal involvement. - Myeloschesis
-
Spina bifida aperta
Neural plate open to surface dorsally (unfused vertebral arches) - Meningomyelocele
-
90% SB Cystica
Cystic swelling
Spinal cord/meninges herniated usually at lumbar level - Meningocele
-
SB Cystica 10%
Only meninges herniated - Spina Bifida occulta
-
Strictly Verteral
-Hair tuft/cyst at defect site
-may confuse w/ diastematomyelia
-10% of adult population - diastematomyelia
- bone spur that teathers spinal cord and prevents ascension
- Error of secondary neurulation
- Myelodysplasia
- Myelodysplasia
-
abnormal formation of caudal part of spinal cord
-maybe covered w/ pigmented skin - Holoprosencephaly
-
-Midline facial/CNS defects
-Primarily affects forebrain
-50% assoc w/ chromosomal defect
-Alcohol ingestion - Errors of Neuron Proliferation
-
-Megalencephaly - large head
-Microencephaly - small head - Erros of Neuron Migration
-
-Lissencephaly
-Micro/macrogyria
-Agenesis of corpus callosum
-Hydrocephalus
-Arnold Chiari - Lissencephaly
-
Smooth brain
-Poor responsive in feeding
-Seizures
-Decr. muscle tone
-Devo delay, microcephaly - Microgyria
-
Small gyri - severe devo delays
-Seizures
-Hypotonia - Macrogyria
-
Large gyri
-Same sx as microgyria - Agenesis of corpus callosum
- may be asymptomatic
- Hydrocephalus
- increased CSF
- noncommunicating hydrocephaly
- obstruction in brain - usually at cerebral aqueduct
- communicating hydrocephaly
- interference w/ resorption
- Arnold-Chiari malformation
-
Caudal displacement and herniation of ventral cerebellar structures
-May be defect in skull base - Duplicated 1st cleft
- blind pouch (fistula) runs from ext meatus to cheek
- Branchial/cervical cyst
- remnant of embryological cervical sinus
- Cervical fistula involving 2nd cleft
- tracks to tonsilar fossa (thru carotid bifurcation
- Cervical fistula involving 3rd cleft
- tracks to superior larynx - pierces thyrohyoid
- Persistent cervical sinus
- opens onto lateral neck anterior to sternocleidomastoid
- Abnormal devo of TONGUE
-
-ankyloglossia
-macroglossia /microglossia - Cause of ankyloglossia:
- failure of apoptosis to free tongue from attachment to mouth floor
- ankyloglossia is aka
- tongue tied
- macroglossia/microglossia are often associated with:
-
downs syndrome
hyperthyroidism - Dacryostenosis
- failure of canalization of nasolacrimal duct
- Choanal atresia
- absence of one or both primitive choanae due to obstruction
- What causes choanal atresia?
- Failure of oronasal membrane to rupture by 38 days
- 2 types of abnormal ethmoid bone formation
-
-Hypotelorism
-Hypertelorism - Hypotelorism
- orbits too close together
- hypertelorism
- orbits too far apart
- Cleft lip - uni/bilateral
-
Failure of fusion of MaxP & MNP
More in Males 2:1 - Oblique facial cleft - oroauricular type
-
Rare
Cleft goes from lateral mouth toward ear (auricle)
Wide mouth - macrostomia - Oblique facial cleft - oroorbital type
- cleft goes from mouth to orbit
- Median cleft lip
- hare lip (rabbit)
- Cleft palates - morphogenic factors:
-
-Abnormal tongue devo; it fails to get out of way of palate elevation and fusion
-Cysts - formed from epithelial remnants from left over palate fusion - rupture and reopen palate.
-Impedment of shelf force - Drugs that impede shelf force:
- Glucocorticoids - interfere with palatal shelf elevation.
- Another name for Mandibulofacial Dystosis:
- Treacher Collins syndrome
- Features of mandibulofacial dystosis:
-
-Clefts of arch 1 structures
-Hypoplastic Zygomatic and mandible bones
-Autosomal dominant - Maxillary hypoplasia is aka
- Crouzon
- Features of Maxillary hypoplasia
-
-Hypoplastic midface
-Hypertelorism
-Coronal suture synostosis
-Malocclusion - Mutation causing Crouzon:
- FgF receptor 2 on Chr' 10
- Mandibular hypoplasia features:
-
-Small jaw
-Glossoptosis (fwd displacement)
-Difficulty of breathing
-Cleft palate - CHARGE
-
Coloboma
Heart defects
Atresia (choanal)
Retardation
Genital hypoplasia
Ear anomalies - 2 neural tube defects associated with first arch syndromes:
-
-Holoprosencephaly
-Aperts syndrome - Drug that induces facial dysplasia:
- Accutane
- Lateral facial dysplasia features:
-
-Small mouth
-Unilateral facial hypoplasia
-Microtia (small ear)
-Hemivertebrae - Agenesis of pharyngeal pouch 1
- failure of one or more salivary glands to develop
- Ranula
- enlargement of salivary glands due to nonpatent duct
- Thyroid agenesis
-
Cretinism
Pituitary dwarf
Mental deficiency - Persistant thyroglossal duct
-
-Cysts
-Fistulas
-Lingual thyroid - Thyroid Cysts will be located:
-
anywhere along path of thyroid primordium
-mobile, noncommunic w/ skin - Thyroid fistula
- rupture of thyroid cyst
- Lingual thyroid
- In body of tongue at foramen cecum
- Absence of 3/4th pouches:
- DiGeorge syndrome
- Features of DiGeorge:
-
-Heart defects
-Minor craniofacial defects
-Hypoplastic mandible
-Cleft palate
-Hypotelorism
-Hypoparathyroidism - Craniopharyngeoma
- Failure of Rathke's pouch to reach posterior portion of pituitary from neural tube
- Anomalies of early eye devo:
-
-Anophthalmia
-Cyclopia to synophthalmia - Anophthalmia
- absence of ocular structures
- More common form of anophthalmia
-
microphthalmia - small eye
(total absence = rare) - Inheritence if isolated
- autosomal recessive
- primary anophthalmia:
-
Restricted to eye
rare
surrounding structures develop normally - secondary anophthalmia:
-
secondary to FOREBRAIN defect
HOLOPROSENCEPHALY - cyclopia
-
1 eye 1 orbit
multifacial anomalies - synophthalmia
-
2 eyes 1 orbit
2 eyes 2 orbits 1 nostril -
Eye structure in
-cyclopia
-synophthalmia -
cyclopia: normal or deformed eye
synophth: varied degree of fusion of eyes or close together - sex cyclopia is more common in
- females
- Condition associated w/ cyclopia or synophthalmia
- HOLOPROSENCEPHALY
- Congenital cataract
- clouding of the eye
- Causes of congenital cataracts
-
Too much PTH - Intrf w/ eye devo
Rubella
Inherited - Congenital glaucoma
- increased ocular fluid pressure
- Causes of congenital glaucoma
- -abnorm devo of fluid draining spacs in eye (junction of sclera and cornea)
- Persistent pupillary membrane
- persistent hyaloid vessels in front of lens
- When hyaloid vessels should regress
- 4rd trimester
- Papillary atresia
- persistant pupillary membrane covers pupil
- 4 types of abnormal eye devo
-
-Coloboma
-Congenital ptosis
-Micropthalmos
-Cryptophtalmos - Coloboma
-
mutilation - rare
-notch in 1+ ocular structures -incomplete choroid fissure closure - Congenital ptosis of eyelid
-
Common
Autosomal dominant
Fail to form Levator Palpebrae - What can cause acquired congenital ptosis
- oculomotor nerve injury
- Micropthalmos
-
rare
decreased eyeball volume
ranges from mild to extreme - Extreme form of microphthalmos:
- Anopthalmia - only have eye remnants
- Cutoff point for whether function will be abnormal in microphthalmos:
-
Before 4 weeks - abnormal
After 8 weeks - normal - Crypopthalmos
- hidden eye - eyelids absent and eyeball is hidden and malformed
-
Anotia - microtia
-sex more common in
-side more often on -
Range of external ear anomalies
-more common in males
-Right ear more common - Association with anotia/microtia
-
Fragile X syndrome
Oligohydramnios via kidney abn - Auricular tags
- appendages along auricle line of speriolateral migration
- Auricular tags associated with:
- not associated w/ other anomalies
-
Auricular sinus
-assoc w/ -
-Anterior/preauricular to ear
-assoc with kidney anomalies and deafness - Otocephaly
-
Failure of auricle to move superolaterally
-very rare - Sx associated with Otocephaly:
-
-Severe micrognathia (small mandible)
-Respiratory problems - cause of death
-CNS deformities
-Persistent oral membrane - Mandibulofacial dysostosis - 1st arch abnormalities assoc w/ ext ear abnormalities
-
-Low set ears
-Deafness
-In addition to facial anomalies - Meatal Atresia/hypoplasia
-
Absence of patent external auditory meatus
-osseous portion usually involved
-bilateral - Anomalies of middle ear
-
-congenital fixn of stapes
-ossicle defects
-choleosteatoma - Congenital fixation of Stapes
-
-Progressive hearing loss
-Autosomal dominant
-Particularly foot of stapes - Ossicle defects
-
ossicles can be solitary bone
-usually bilateral - Choleosteatoma
-
Benign growth of endoderm origin
-In the tympanic cavity medial to ear drum - Anomaly of Iner ear
- Vestibulocochlear Dysplasia
- Vestibulocochlear Dysplasia
-
-Flattened cochlea
-Decr. # of turns
-Underdevolpd vestibular structures
-Osseous/membranous structures involved too - Largest cause of hearing loss:
- Congenital
- Age of diagnosis for congenital hearing loss:
- 2-3 yrs
- 3 types of cong hearing loss:
-
-Conduction
-Sensorineural
-Mixed - Conduction cong hearing loss:
- External and/or middle ear problems - sound not transmitted to cochlea
- Sensorineural cong hearing loss:
-
Inner ear and/or nerve problems
-no signal generated
-thus no transmission to brain - Causes of cong hearing loss:
-
-Heredity (30-50%)
-Prenatal infxn (rubella, CMV, toxoplasmosis, syphilis, herpes)
-Environmental (thaladomine, acutane)Hypothyroid
-Unknown 30%