Developmental Pathogenesis of Common Malformations

Question 1

The series of steps that lead to a disease state

Answer 1

Pathogenesis

Question 2

Major anomaly

Answer 2

*A congenital anomaly that causes a problem requiring medical or surgical intervention
*ex: Heart defect, cleft lip or palate, Hirschsprung

Question 3

Minor anomaly

Answer 3

*A developmental difference that may be important for diagnosis, but has no physical impact
*ex: Single palmar crease, clinodactyly

Question 4

*Developmental process is normal
*An external factor produces abnormal shape due to pressure and/or restriction of growth and movement
*ex: Club foot

Answer 4

deformation

Question 5

*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

Answer 5

plagiocephaly

Question 6

*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

Answer 6

disruption

Question 7

What is Kippel Feli?

Answer 7

• fusion of of cervical (neck) vertebrae
• majority sporatic
• hypothesized to be “subclavian artery supply disruption sequence”

Question 8

• bilateral facial and abducens nerve palsies
• facial paralysis
• “cross eyed”

Answer 8

Mobieus

Question 9

Poland “Syndrome”

Answer 9

• bilateral facial and abducens nerve palsies
• facial paralysis
• “cross eyed”

Question 10

Hemifacial microsomia

Answer 10

*AKA: Oculoariculovertebral spectrum
*AKA: Goldenhaar syndrome
*Microtia
*Facial asymmetry
*Epibulbar dermoid
*Vertebral anomalies (Klippel Feil)

Question 11

Malformation

Answer 11

*A malformation is birth anomaly in which the developmental was intrinsically abnormal
*Examples: holoprosencephaly, congenital heart disease, neural tube defect

Question 12

Dysplasia

Answer 12

*A malformation is birth anomaly in which the developmental was intrinsically abnormal
*Examples: holoprosencephaly, congenital heart disease, neural tube defect

Question 13

Hyperplasia

Answer 13

Excessive growth

Question 14

Hypoplasia

Answer 14

Inadequate growth/under-development

Question 15

a normal structure shrinks over time

Answer 15

atrophy

Question 16

Ectodermal dysplasia

Answer 16

Abnormal or poor development of ectodermal derived structures
Sparse, coarse hair Conical, missing teeth Skin * Sweat glands * Nails * “Dystrophic”

Question 17

Syndrome

Answer 17

*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

Question 18

What are features of Fetal Alcohol Syndrome?

Answer 18

*Growth retardation
*Microcephaly
*Intellectual disability
*Short palpebral fissures
*Short nose
*Smooth philtrum
*Thin upper lip
*Small distal phalanges
*Hypoplastic finger nails
*Cardiac defects

Question 19

Sequence

Answer 19

*“One thing leads to another”
*Can involve multiple mechanisms, including malformation, disruption, and deformation

Question 20

What are features of Pierre Robin Sequence?

Answer 20

• small mandible
  *tongue displaced posteriorly
  *tongue blocks the fusion of the palate in the midline
• in severe cases tongue even impairs formation of larynx

Question 21

Association

Answer 21

*A collection of anomalies that are recognized to be co-occurring at higher-than-expected statistical chance
* ex: VACTERL