4p- syndrome and 9p tetrasomy mosaicism with cleft lip and palate.

Chromosome 4p- syndrome is a multiple malformation syndrome associated with partial deletion of the short arm of chromosome 4 (4p-). It is characterized by dysmorphic features and retarded development. Cleft lip and/or palate are the major clinical manifestations. Cases of tetrasomy 9p are extremely rare; the principal clinical manifestations of this condition are characteristic craniofacial abnormalities, generalized hypotonia and severe mental retardation. We present the first case of a female infant with 4p deletion and tetrasomy 9p mosaicism, exhibiting a left-sided cleft lip, alveolus and soft palate. Karyotype analysis of lymphocytes cultured from the patient revealed that she was mosaic: 86% of the cells were 46, XX, add (4) (p15.32) and 14% were 47, XX, add (4) (p15.32), +idic (9)(q12). The G-banding pattern appeared consistent with either translocation or partial proximal deletion of 4p. In order to make a definitive cytogenetic diagnosis of isodicentric chromosome 9, fluorescence in situ hybridization (FISH) was applied. At 8 months, when the patient weighed 4.3 kg, her cleft lip was repaired. Before and after surgery there were no seizures, and the postoperative course was uneventful.