UCSF - Craniofacial/Developmental syndromes Flashcards
What is the most common type of short limbed dwarfism?
Achondroplasia
Describe what happens in Acondroplasia?
Disturbance of endochondral bone formation
Achondroplasia is due to a defect in what particular cellular mechanism?
Due to defect of the FGFR3 growth receptor
Describe the clinical signs of Achondroplasia
- Brachycephalic
- Retruded maxilla due to decreased cranial base growth (Cl III)
- Shortened long bones
- Normal intelligence
In Achondroplasia, which jaw (maxilla or mandible) growth is abnormal?
Maxillary growth - the length is shorter
Describe the reason for maxillary deficiency in Achondroplasia.
Length is shorter due to deficient nasal capsule growth, the palatal plane tipped inferiorly in posterior and deficient infraorbital rims.
What is Acromegaly?
A chronic disease of adults caused by an anterior pituitary tumor which secretes excess growth hormone causing excessive growth of the mandible and a skeletal class III malocclusion.
> 95% of acromegaly cases result from what? And does it occur more in women or men?
Results from a pituitary adenoma and occurs more in men
Describe the facial changes in patients with Acromegaly
- Prominent Supraorbital Ridges
- “Hanging” Columella from septal cartilage overgrowth
- Prognathic Mandible
- Soft Tissue Swelling
Describe radiographic changes in patients with Acromegaly
- Increased thickness of calvarium
- Frontal sinus enlargement
- Sella Tursica enlargement (93%)
What is the difference between Acromegaly and Gigantism?
It is differentiated by the fusion of the epiphyseal growth plates.
Before closure = gigantism
After closure = acromegaly
How is Aperts Syndrom inherited?
Autosomal Dominant trait caused by mutation in FGFR2
Name the gene that is mutated in Aperts Syndrome
FGFR2
A mutation in Aperts Syndrome causes what clinical feature?
Craniosynostosis
Which suture is most commonly fused prematurely in Aperts Syndrome
Coronal Suture
T/F Patients with Apert’s syndrome show signs of intellectual disability
True.
Clinical Signs of Apert’s syndrome
- Midfacial malformations & retrusion
- Cleft of soft palate
- Stapes fixation
- Small beaklike nose
- Exopthalmos
- Hypertelorism & Strabismus
- Syndactyl
- Intellectual Disability
How is Carpenter syndrome inherited?
Autosomal recessive - mutation that is passed
What is the mutation in Carpenter syndrome
RAB23 gene, located on chromosome 6
Clinical signs of Carpenter syndrome
- Midface retrusion
- High arched palate
- Low-set and small ears
- Extra digits
- Webbing of fingers
- shorter digits
- Heart defects
- Microgenitalism
- Lip pits
How is Crouzons syndrome inherited?
Autosomal dominant - mutation
What gene is the mutation found on in Crouzons?
FGFR2/3
What is the most common form of craniosynostosis?
Crouzons
Clinical signs of Crouzons?
- Underdeveloped midface, receded cheekbones or exophthalmos
- supernumerary teeth and delayed eruption of teeth
- Cleft palate may be associated
- Normal mental capacity
How to prevent blindness in Crouzons?
LeFort I
Name the mutations of Pfeiffer syndrome
FGFR-1 or FGFR2
Located on chromosomes 8 & 10 respectively
Pfeiffer syndrome shows what unique feature
chiari malformation - cerebellar tonsil (cerebellum gets pushed through foramen magnum)
Which syndrome with craniosynostosis is associated with a “central sleep apnea”
Pfeiffer syndrome
Name the mutation of Saethre-Chotzen
TWIST gene, located on Chromosome 7
How is the mutation in Saethre-Chotzen inherited
Autosomal dominant
Describe Scaphocephaly
A specific variety of a long narrow head that resembles an inverted boat
What suture is involved in Scaphocephaly
Premature fusion of the sagittal suture.