Campomelic dysplasia is a very rare disorder characterised by a variable association of skeletal abnormalities (bowed and fragile long bones, pelvis and chest abnormalities, eleven rib pairs instead of the usual twelve), and extraskeletal abnormalities (facial dysmorphology, cleft palate, sexual ambiguity or sex reversal in two thirds of the affected boys, and brain, heart and kidney malformations).
Prevalence at birth is approximately 1/300 000.
A few cases of a variant syndrome, referred to as ``acampomelic campomelic dysplasia'' have been described. This variant can be distinguished by the lack of long bone curvature.
The syndrome is associated with anomalies in the SOX9 gene (localized to 17q24), either as a result of chromosomal recombination involving this locus or due to heterozygous de novo mutation of this gene.
Diagnosis is generally suspected prenatally during the second-trimester ultrasound examination, based on the observation of delayed growth associated with bone abnormalities and potentially male pseudohermaphrodism.
Prenatal genetic testing can be performed through amniocentesis or chorionic villus sampling when there is a suspicion of the diagnosis or in familial cases where an abnormality of the chromosomal region has already been identified.
Treatment is symptomatic.
Newborns suffering from campomelic dysplasia often die soon after birth as a result of respiratory insufficiency, but 5 to 10 % of individuals survive. Complications (such as cyphoscoliosis, recurrent respiratory infections, hearing loss, light to moderate learning difficulties, small size and hip dislocation) can arise as the patients age.
Last update: January 2007