omodysplasia type 1

omodysplasia type 1

A rare autosomal recessive skeletal dysplasia (OMIM:258315) characterised by severe congenital micromelia with shortening and distal tapering of the humeri and femora to give a club-like appearance. Typical facies include a prominent forehead, frontal bossing, short nose with a depressed broad bridge, short columella, anteverted nostrils, long philtrum and small chin.
Molecular pathology
Defects in GPC6, which encodes the cell surface proteoglycan glypican 6, cause omodysplasia type 1. Molecular changes include: point mutations of GPC6, leading to protein truncation, and larger genomic rearrangements resulting in exon deletions. All mutations in omodysplasia can lead to absence of functional glypican 6.