Dysmorphology Flashcards
What is dysmorphology?
The study of human congenital malformations (birth defects), particularly those affecting the anatomy (morphology) of the individual.
May be:
- Facial
- Skeletal
- Anatomical
What are some causes/reasons for dysmorphisms?
- Malformation: structural defect due to abnormal embryonic or fetal development
- Deformation: abnormality caused by physical stress to normal tissue
- Disruption: alteration of normally forming structures by extrinsic process
- Dysplasia: abnormal development/organization of cells or tissues
What are some ground rules for dysmorphic features?
- Everyone has at least 1 dysmorphic feature.
- Most genetic syndromes have several dysmorphic features involving more than one system.
- It’s the constellation of findings that makes the diagnosis
Where to start with the evaluation of dysmorphic features?
- Height
- Weight
- FOC
- Shape
- Proprotions
Head size is a key feature of what disorder?
Achondroplasia
What is the definition of macrocephaly?
FOC > 98th percentile
What is Rhizomelic short stature?
Disproportionate short stature
- Short proximal segments of limbs
(The opposite is mesomelic; disproportionate short stature with short distal segments of limbs)
What is the definition of microcephaly?
FOC < 2nd percentile
What syndromes is microcephaly seen in?
- Rubinstein Taybi syndrome (left)
- Seckel syndrome (right)
- Others
Microbrachycephaly is seen in what condition?
Down syndrome
Label the sutures
Think about the deformities that would occur if a suture closes too early
What is brachycephaly?
Short AP length of skull
What is dolichocephaly?
Long AP length of skull
What is trigonocephaly?
Triangular-shaped skull
What is turricephaly?
Tall head
What is craniosynostosis? What condition is it seen in?
Apert syndrome
What are the criteria for determining if the ears are low set?
- Draw a line from medial canthi and extend across to the ears
- This line should cross the superior attachment of the ear
What is one condition with low set ears?
- Other clinical associations
Noonan syndrome
- Also associated with heart defects
What is Branchio Oto Renal Syndrome?
Something to consider if your patient has dysmorphic ears
What is hypertelorism? Hypotelorism?
Hypertelorism is eyes being set too far apart; hypotelorism is too close
- Normal distance between eyes should be equal to width of 1 eye