X-linked recessive chondrodysplasia punctata: cytogenetic and molecular biology study.

Among the many acquired or constitutional causes of chondrodysplasia puncta ta, the X-linked recessive form is well individualized. Case report. - A male newborn presented a dysmorphic syndrome with a marked nasal hypoplasia, a macroglossia and a short neck. The diagnosis of chondr odysplasia punctata was made by radiography whereas the chromosomal chart r evealed 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 sul fatase E and the microsatellite DXS 1233, sping gene MRX2 (non-specific gen e of mental retardation), and making it possible to give the reassuring ele ments as regards the psychomotor prognosis, sometimes compromised in this d isorder. Conclusion. - In case of chondrodysplasia punctata with dysmorphy, it is im portant to execute a chromosomal chart in the search for a chromosomal reor ganization on the X and a study in molecular biology. (C) 2001 Editions sci entifiques et medicales Elsevier SAS.