Interstitial deletion of the long arm of chromosome no. 5 in two unrelated children with congenital anomalies and mental retardation.

Two unrelated children with partial deletion of the long arm of a chromosome no. 5 are reported. The boy presented with severe hypotonia, developmental delay, and a few minor defects of the face including frontal bossing, antimongoloid slant of the palpebral fissures, depressed nasal bridge and bilateral epicanthal folds. With age, his hypotonia has improved. The parents have normal chromosomes; the mother has a 9qh+ variant. The second patient, a girl, presented at birth with multiple congenital anomalies including cleft palate, epicanthal folds, anteverted nostrils, horseshoe kidneys and club feet. At 4 years of age, she was small and severely retarded. The normal parents and the normal sister showed no chromosomal abnormalities. Gene mapping studies in both patients failed to define a specific gene locus to the deleted chromosome regions. Including these two patients, there appear to be only three reported cases of patients with 5q deletion. A comparative description of the third patient is included in this report. There are some clinical similarities but these are inadequate to identify a clinical syndrome. This perhaps is explained by some quantitative and qualitative differences in the deletions.