Proximal deletion of the long arm of chromosome 1: [del(1)(q23-q25)].

A patient with bilateral complete cleft of the lip and palate (CLP) had a proximal deletion of the long arm of chromosome 1 (1q). This rare chromosomal abnormality was characterized by pre- and postnatal growth retardation, psychomotor retardation, and specific craniofacial and other systemic anomalies. There is a high incidence of CLP in proximal 1q deletion syndrome, especially bilateral CLP. Twelve other cases reported in the literature having this deletion and associated anomalies were reviewed.