Patterns of chromosomal deletions identified by a birth defects registry, Hawaii, 1986-2003.

The aim of the investigation was to describe the chromosomal deletions identified by a birth defects registry with respect to the chromosomes involved, pregnancy outcome, method of diagnosis, inheritance, sex, and the diagnosis of major structural birth defects. Cases were derived from a population-based birth defects registry in Hawaii and comprised all infants and fetuses with chromosomal deletions delivered during 1986-2003. A total of 71 cases were identified through a statewide birth defects registry in Hawaii during 1986-2003. The chromosomes involved in the greatest proportion of deletions were chromosomes 22 (14.1%), 4 (11.3%), and 5 (11.3%). Live births accounted for 58 (81.7%) of the cases. Diagnosis was made by amniocentesis or chorionic villus sampling in 19 (26.8%) of the cases. Of the 18 cases with known inheritance, the deletion was inherited in 5 (27.8%) and de novo in 13 (72.2%). Males accounted for 28 (39.4%) and females for 43 (60.6%) of the cases. Major structural birth defects were identified in 51 (71.8%) of the cases. Chromosomal deletions do not appear to affect all chromosomes equally. Most of the chromosomal deletions that were detected occurred among live births and were de novo conditions. Infants and fetuses with chromosomal deletions are more likely to be females and to be associated with major structural birth defects.