CLEIDOCRANIAL
DYSOSTOSIS (DYSPLASIA)
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Cleidocranial dysostosis is an autosomal dominant disorder characterized by
absence or hypoplasia of the clavicles, abnormalities of the skull and abnormal
dentition. The prognosis appears to be related to the extent of orthopedic
involvement, with wide variability of manifestations, even within the same
family. The lifespan of the individual is normal.
A gene for cleidocranial dysostosis has been mapped to the short arm of
chromosome 6 (1). A mutation in the gene for transcription factor CBFA1 on
chromosome 6p21 is present in some families (2). There have also been reports
of abnormalities of chromosome 8q22 in individuals with cleidocranial dysplasia
suggesting another possible genetic locus in some families (3).
Cleidocranial dysplasia has been diagnosed as early as 14+4
weeks (4).
- Hypoplasia or aplasia of the
clavicles (below the 5th percentile for gestational age).
- Unilateral or
bilateral involvement.
- Skull:
- Hypomineralization
with late ossification of sutures.
- Brachycephaly and flat
occiput.
- Frontal, parietal and
occipital bossing of the fetal cranium.
- Large fontanelles, wide
sutures and wormian bone.
- Facial bones:
- Abnormal dentition
with abnormal dentition and delayed eruption of teeth.
- Midface hypoplasia
with a low nasal bridge.
- Thorax may be small with
short oblique ribs.
DIFFERENTIAL DIAGNOSIS OF HYPOPLASTIC CLAVICLES
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- Pyknodysostosis.
- Jansen
metaphyseal chondrodysplasia and osteodysplasia.
- Yunis-Varon
syndrome.
- Mandibuloacral
dysplasia.
- Osteogenesis
imperfecta.
- Chromosomal
abnormalities – partial trisomies of chromosomes 11 and 20.
- Feldman GJ, Robin NH, Brueton
LA et.al. A gene for cleidocranial dysplasia maps to the short arm of
chromosome 6.
Am J Hum Genet 1995;56:938-943.
- Mundlos S, Otto F, Mundlos C,
Mulliken JB, Ayslworth AS .et.al. Mutations involving the transcription
factor CBFA1 cause cleidocranial dysostosis. Cell 1997;89:773-779.
- Mundlos S, Mulliken JB,
Abramson DL, Warman ML et.al. Genetic mapping of cleidocranial dysplasia
and evidence of microdeletion in one family. Hum Mol Genet 1995;1:71-75.
- Srewart PA, Wallerstein R,
Moran E, Lee M –J. Early prenatal diagnosis of cleidocranial dysplasia.
Ultrasound Obstet Gynecol 2000;15:154-156.
- Hamner LH, Fabbri EL, Browne
PC. Prenatal diagnosis of cleidocranial dysostosis. Obstet Gynecol
1994;83:856-857.
- Hassam J, Sepulveda W,
Teixeira J et.al. Prenatal sonographic diagnosis of cleidocranial
dysostosis. Prenat Diagn 1997;17:770-772.