skeletal dysplasia

Question 1

rhizomelic shortening

macrocephaly

frontal bossing

midface retention

Answer 1

Achondroplasia

AD

FGFR3 - membrane spanning tyrosine-kinase receptor

Question 2

99% of achondroplasia are due to these specific variants

Answer 2

c. 1138G>A p.Gly380Arg
c. 1138G>C p.Gly380Arg

Gain-of function mutations

(constituive activation of FGFR3

Inhibition of chondrocyte proliferation and differntiation)

Question 3

deayed closure of cranial sutures

hypoplastic/aplastic clavicles

dental abnormalities

Answer 3

Cleidocranial Dysplasia

RUNX2

AD

Question 4

Most common nonsyndromic craniosynostosis

Answer 4

Sagittal: 50-60%

Question 5

cyctic ear swelling

limb shortening

normal size skull

hitchhicker thumbs

spinal deformities and contrsctires

early osteoarthritis

Answer 5

Diastrophic Dysplasia

SLC26A2

Question 6

FGFR3

Syndromic Craniosynostosis

Answer 6

Muenke Syndrome

Question 7

FGFR2

Syndromic Craniosynostosis

Answer 7

Apert Syndrome - maxillary hypoplasia and syndactyly of hands and feete

Crouzon syndrome- normal ID, ocular proptosis and shallow orbits

Question 8

FGFR1

Syndromic craniosynostosis

Answer 8

Pfeiffer Syndrome- Broad thumbs and great toes (medial deviation)

Question 9

Coronal synostosis

facial asymmetry

ptosis

2/3 hand syndactly

characteristic ear

Answer 9

Saethre-Chrotzen Syndrome

TWIST1

Question 10

coronal synostosis

hypertelorism

grooved nasal tip

+/- cleft lip or palate

Answer 10

Craniofrontonasal Syndrome

X-linked

EFNB1