Abstract
A case of a female infant with malformations of upper extremities and mental and growth retardation is reported. The karyotype showed a 46,XX,t(Bq+;Dq−)/45,XX,−B,−D,+der(B),t(Bq+;Dq−) mosaicism. The clinical findings in relation to the long arm deletion of a B-group chromosome are discussed.