Molecular cytogenetic analysis of a constitutional de novo interstitial deletion of chromosome 12p in a boy with developmental delay and congenital anomalies.

We describe the case of a 6-month-old boy with psychomotor retardation, craniofacial dysmorphism, cleft lip and palate, as well as hearing and visual impairment. Analysis of G-banded chromosomes of the propositus showed a de novo interstitial deletion of the short arm of chromosome 12, del(12)(p12.1p12.3). Molecular cytogenetic analysis with bacterial artificial chromosomes (BAC) clones was used to refine the extent of the deletion. The deleted segment encompasses about 12.5 Mb between markers D12S1832 and G62375. The phenotypic consequences of the deletion are discussed and compared with other cases of interstitial deletions of proximal chromosome 12p.