Pierre Robin sequence and interstitial deletion 2q32.3-q33.2

Pierre Robin sequence (PRS) consists of the nonrandom association of micrognathia, cleft palate (CP), and glossoptosis. It also includes respiratory and feeding difficulties that appear to be neurogenic rather than mechanical in causation. Genetic determinants are thought to underlie this functional and morphological entity, based on the existence of Mendelian syndromes with PRS, and the rare observations of familial nonsyndromic PRS, in which some of the affected individuals have isolated CP. We report the association of PRS with deletion 2q32.3-q33.2 due to an unbalanced reciprocal translocation 46,XX, t(2;21), del 2(q32.3q33.2), and we refine the deletion interval with regard to YAC probes and polymorphic DNA markers. The deletion was shown to be flanked by D2S369 (telomeric) and D2S315 (centromeric), thus it maps to a recently determined chromosomal region known to be nonrandomly associated with CP. This observation supports the hypothesis for the genetic bases of nonsyndromic PRS, strengthens its possible genetic association with isolated CP, and provides a candidate PRS locus, in chromosomal region 2q32.3-q33.2.