DUPLICATION AND DELETION OF CHROMOSOME BAND 2(P21P22) RESULTING FROM A FAMILIAL INTERSTITIAL INSERTION (211)(P21P15)

Routine amniocentesis for advanced maternal age led to the prenatal di agnosis of a fetus with a karyotype of a 46,XX,del(2)(p21p22). At deli very the baby had holoprosencephaly as the major clinical finding, whi ch has been associated with a deletion of band 2p21 in several other c ase reports. Chromosome studies of the parents showed a normal 46,XY k aryotype in the father, and a balanced interstitial insertion 46,XX di r ins (11;2)(p15.l;p21p22) in the mother. Subsequent chromosome studie s of other relatives documented a 23-year-old half-brother of the prop osita with a partial trisomy for the segment deleted in the proposita. The half-brother showed the derivative chromosome 11 from the mother, resulting in a 46,XY,der(11)dup(2)(p21p22) karyotype. Major clinical findings include short stature, mild developmental delay, and behavior abnormalities. A half-sister of the proposita is also a balanced carr ier of the the dir ins (11;2) (p15.l;p21p22.2). The association of the deletion chromosome band 2p21 and the clinical finding of holoprosenc ephaly is further supported by the findings in this family. (C) 1994 W iley-Liss, Inc.