2. Patient Symptoms?
Patient was born at 21 weeks with Wolf
Parkinson's White and an
underdeveloped epiglottis
Severe dislocation of all joints (hips,
knees, elbows, ankles, ect.
Additional bones in wrists and ankles
Some fingers are square shaped and
shorted fingers and toes
3. Symptoms Cont.
Toes also misshaped
Flattening of the bridge of the nose and
middle of the face
Loose joints
Abnormal curvature in spine
4. Tests Preformed?
Fetal ultrasound
True diagnosis is only reached through
molecular genetic testing
Larsen Syndrome is a genetic mutation
Sequencing of the FLNB gene can be
used to identify if a mutation is present
6. Cause?
A mutation in the Gene Encoding
Filamin B
Larsen Syndrome is caused by a
missense mutation in the gene that
codes for filamin B
Casue an accelerated rate of apoptosis in
epiphyseal growth plates
7. BioMolecule: Filamins
Cytoplasmic proteins
Regulate structure and activity of
cytoskeleton
Work as bridge where intracellular
signaling and protein interactions occur
Filamin B
Found in human growth pate
chondrocytes
8. Filamins Cont.
Class of proteins the hold two actin
filaments at large angles
Made up of an actin binding domain at
its N-terminus that is followed by 24
immunoglobulin like segments (~95
amino acids)
Act like the flexible cross-joints that
support skyscrapers in earthquake
zones.
9. Gene Analysis
Gene linked to Larsen Syndrome
(LAR1) is linked to chromosome 3p
markers
3p chromosome region is 3p21.1-14.1
The Human type VII collagen gene is
found within this region
Some abnormalities associated with
Larsen Syndrome are related to the
Human type VII collagen gene
