11/3- Dysmorphic Features 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 telecanthus?
Inner canthal distance is much closer to interpupillary distance than it should be (?)
What is seen here?
- Close-set eyes
- Cleft
- Not much midface
This indicates holoprosencephaly
- Trisomy 13
- Pt could have a translocation (if so, one parent could be a translocation carrier and this may affect subsequent births)
Describe these palpebral fissures
- Left: downslanting palpebral fissures (Noonan syndrome)
- Right: upslanting palpebral fissures (Down syndrome)
What are the abnormalities seen in these eyes? What are the associated syndromes/clinical features?
- Top left: Coloboma
- Top right: Lisch nodules (neurofibromatosis)
- Bottom left: heterochromia (Waardenburg’s syndrome; hearing loss)
- Bottom right: Brushfield spots (Down’s syndrome)
What ocular abnormalities are seen here?
What are the associated diseases/clinical features?
- Top left: Epibulbar dermoid (Goldenhar syndrome)
- Top right: slate-grey sclera (Osteogenesis imperfecta)
- Bottom: leukocoria (retinoblastoma)
What is seen here? Seen in what condition?
Tubular nose
- May be seen in Velocardiofacial syndrome (del22q11.2); look for family history
What is seen here?
Seen in what condition?
Anteverted nares
- May be seen in Smith-Lemli-Opitz syndrome (AR)
What conditions are associated with mouth, philtrum, and chin changes?
- Prader-Willi Syndrome (short philtrum?)
- Cornelia de Lange Syndrome
- Fetal alcohol syndrome (long, smooth philtrum; thin upper lip)
- Fragile X syndrome (big chin)
Types of cleft lip?
- Unilateral incomplete
- Unilateral complete
- Bilateral complete
Types of cleft palate?
- Incomplete cleft palate
- Unilateral complete lip and palate
- Bilateral complete lip and palate
If cleft palate + micrognathia (small chin), think of what?
Stickler syndrome (AD)
If cleft palate + micrognathia + antiverted nares, think what?
Smith Lemli Opitz syndrome (AR)
if cleft palate + tubular nose + small ears, think what?
Deletion 22q11.2 (Velocardiofacial syndrome?)
If cleft palate + holoprosencephaly, think what?
Heterogeneous etiology
What is clinodactyly?
Curved finger (folds are not parallel) because bone is wedge-shaped
- Seen commonly in Down syndrome
Another feature you may see in the hand of someone with Down syndrome?
Single transverse palmar crease
Other dactylies…
What causes this?
Amniotic bands
What is seen here?
Club feet (foot unable to be placed flat on floor)
What is seen here?
Rocker-Bottom foot (seen in trisomy 13?)
