Developmental Pathogenesis of Common Malformations Flashcards
The series of steps that lead to a disease state
Pathogenesis
Major anomaly
*A congenital anomaly that causes a problem requiring medical or surgical intervention
*ex: Heart defect, cleft lip or palate, Hirschsprung
Minor anomaly
*A developmental difference that may be important for diagnosis, but has no physical impact
*ex: Single palmar crease, clinodactyly
*Developmental process is normal
*An external factor produces abnormal shape due to pressure and/or restriction of growth and movement
*ex: Club foot
deformation
*Deformation
*Asymmetric head shape, which is usually a combination of unilateral occipital flattening with ipsilateral frontal prominence, leading to rhomboid cranial shape
*Molding of the head common at birth and usually resolves
plagiocephaly
*Developmental process is normal, but interrupted
*Morphologic defect resulting from the extrinsic breakdown or interference with a normal developmental process
*Like deformation, the developmental process would have been normal
*Low recurrence risk
* ex: Alcohol, medications, amniotic bands
disruption
What is Kippel Feli?
- fusion of of cervical (neck) vertebrae
- majority sporatic
- hypothesized to be “subclavian artery supply disruption sequence”
- bilateral facial and abducens nerve palsies
- facial paralysis
- “cross eyed”
Mobieus
Poland “Syndrome”
- bilateral facial and abducens nerve palsies
- facial paralysis
- “cross eyed”
Hemifacial microsomia
*AKA: Oculoariculovertebral spectrum
*AKA: Goldenhaar syndrome
*Microtia
*Facial asymmetry
*Epibulbar dermoid
*Vertebral anomalies (Klippel Feil)
Malformation
*A malformation is birth anomaly in which the developmental was intrinsically abnormal
*Examples: holoprosencephaly, congenital heart disease, neural tube defect
Dysplasia
*A malformation is birth anomaly in which the developmental was intrinsically abnormal
*Examples: holoprosencephaly, congenital heart disease, neural tube defect
Hyperplasia
Excessive growth
Hypoplasia
Inadequate growth/under-development
a normal structure shrinks over time
atrophy
Ectodermal dysplasia
Abnormal or poor development of ectodermal derived structures
Sparse, coarse hair Conical, missing teeth Skin * Sweat glands * Nails * “Dystrophic”
Syndrome
*A recognizable pattern of anomalies presumed to be causally related
*Genetic: chromosomal, single gene
*Environmental: alcohol, retinoic acid
*Complex: more than one genetic and/or environmental factor
What are features of Fetal Alcohol Syndrome?
*Growth retardation
*Microcephaly
*Intellectual disability
*Short palpebral fissures
*Short nose
*Smooth philtrum
*Thin upper lip
*Small distal phalanges
*Hypoplastic finger nails
*Cardiac defects
Sequence
*“One thing leads to another”
*Can involve multiple mechanisms, including malformation, disruption, and deformation
What are features of Pierre Robin Sequence?
- small mandible
*tongue displaced posteriorly
*tongue blocks the fusion of the palate in the midline - in severe cases tongue even impairs formation of larynx
Association
*A collection of anomalies that are recognized to be co-occurring at higher-than-expected statistical chance
* ex: VACTERL
