[X-linked recessive chondrodysplasia punctata. Cytogenetic study and role of molecular biology]

Among the many acquired or constitutional causes of chondrodysplasia punctata, the X-linked recessive form is well individualized.

A male newborn presented a dysmorphic syndrome with a marked nasal hypoplasia, a macroglossia and a short neck. The diagnosis of chondrodysplasia punctata was made by radiography whereas the chromosomal chart revealed the existence of an additional Y fragment in Xpter, effectuating a partial disomy Yp and a monosomy Xpter. Molecular biology showed a deletion of very small size, isolated and located between the gene missing aryl sulfatase E and the microsatellite DXS 1233, sping gene MRX2 (non-specific gene of mental retardation), and making it possible to give the reassuring elements as regards the psychomotor prognosis, sometimes compromised in this disorder.

In case of chondrodysplasia punctata with dysmorphy, it is important to execute a chromosomal chart in the search for a chromosomal reorganization on the X and a study in molecular biology.