Physical findings in 21q22 deletion suggest critical region for 21q- phenotype in q22.

Multiple abnormalities were observed in a newborn infant with a deletion in the long arm of chromosome 21, from band 22q22.1-->qter. The phenotype of this infant was similar to that previously described in infants with deletions spanning the long arm of chromosome 21, from the centromere to 21q22 [Rethoré et al., 1972, Exp Cell Res 70:455-456, 1973, Ann Genet (Paris) 16:271-275]. However, as a phenotypically normal child with normal intelligence and with deletion of 21q11.1-21q21.3 has also been identified [Korenberg et al., 1991, Hum Genet 87:112-118], this case suggests that the critical region of deletion for the 21q- phenotype lies distal to 21q21, within 21q22.1-22.2.