Fibrochondrogenesis 1 (FBCG1)
Fibrochondrogenesis 1 (FBCG1)
OMIM number: 228520
Comments closing date: 27/06/2025
Fibrochondrogenesis is a rare skeletal dysplasia
caused by mutations in either the COL11A1 or
COL11A2 genes. Most cases are recessive but at
least one occurrence of type 2 has been reported
that was due to a de novo dominant mutation in
COL11A2. These two genes together encode the
protein for Type XI collagen, which is a key
component of cartilage and bone tissue, as well as
being needed for clear gel tissues in the inner ear,
eyeball and spinal vertebrae. Fibrochondrogenesis
type 1 is caused by mutations in COL11A1.
Fibrochondrogenesis type 2 is caused by
mutations in COL11A2. Impaired collagen
production, and subsequent abnormal collagen
leads the skeletal, vision and hearing problems.
Typically babies born with this condition have a
very narrow chest, preventing normal lung
development. As a result this condition is often
lethal in infancy due to respiratory problems.
Infants who survive will be affected with short
stature and skeletal abnormalities (shortened
dumbbell-shaped long bones; a narrow chest with short, wide ribs and a round and prominent
abdomen; flattened vertebrae; abnormal curvature
of the spine; underdeveloped pelvic bones).
People with this condition also have hearing and
vision problems and distinctive facial features.
Review date: 16 May 2027
