Paternal balanced reciprocal translocation t(9;22)(q34.3;q11.2) resulting in an infant with features of the 9q subtelomere and the 22q11 deletion syndromes due to 3:1 meiotic segregation and tertiary monosomy.

The constitutional chromosomal reciprocal translocation (CRT) involving chromosomes 9 and 22 has been previously published in only five occasions. We report the sixth case of a balanced t(9;22) carrier who came to medical attention following the birth of his child with tertiary monosomy due to 3:1 meiotic segregation. This is only the second occurrence of paternal parent-of-origin to the t(9;22) CRT and is the first report of a t(9;22) undergoing 3:1 disjunction. It is also unique in its constellation of clinical features that overlap with two well-described cytogenetic microdeletion syndromes: the 9q subtelomeric and 22q11.2 deletion syndromes. With its uncommon breakpoint at chromosome 9q34, this case also emphasizes the added importance of array comparative genomic hybridization to analysis of offspring born to CRT carrier parents. Copyright 2009 Wiley-Liss, Inc.