INTERSTITIAL DELETION, DEL(4)(Q12Q21.1), OWING TO DE-NOVO UNBALANCED TRANSLOCATION IN A 2-YEAR OLD GIRL - FURTHER EVIDENCE THAT THE PIEBALDTRAIT MAPS TO PROXIMAL 4Q12

A very short, microcephalic, and mentally retarded 2 year old girl sho wed minor anomalies including prominent occiput, delayed closure of th e anterior fontanelle, high frontal hairline, prominent ears, upward s lanting palpebral fissures, a small nose with bulbous tip, delayed too th eruption and bone maturation, and short and tapering fingers and to es. She did not have a white forelock. Cytogenetic investigation discl osed a de novo unbalanced translocation between chromosomes 4 and 18 w ith deletion of 2q12-->q21.1. Molecular investigation showed lack of a paternal allele for the microsatellite markers D4S392 and D4S398. Thi s case shows indirect evidence that the piebald gene maps to proximal 4q12.