The Unrecognized Mortality Burden of Genetic Disorders in Infancy.

Objectives. To determine how deaths of infants with genetic diagnoses are described in national mortality statistics. Methods. We present a retrospective cohort study of mortality data, obtained from the National Death Index (NDI), and clinical data for 517 infants born from 2011 to 2017 who died before 1 year of age in the United States. Results. Although 115 of 517 deceased infants (22%) had a confirmed diagnosis of a genetic disorder, only 61 of 115 deaths (53%) were attributed to International Classification of Diseases, 10th Revision codes representing congenital anomalies or genetic disorders (Q00-Q99) as the underlying cause of death because of inconsistencies in death reporting. Infants with genetic diagnoses whose underlying causes of death were coded as Q00-Q99 were more likely to have chromosomal disorders than monogenic conditions (43/61 [70%] vs 18/61 [30%]; P < .001), which reflects the need for improved accounting for monogenic disorders in mortality statistics. Conclusions. Genetic disorders, although a leading cause of infant mortality, are not accurately captured by vital statistics. Public Health Implications. Expanded access to genetic testing and further clarity in death reporting are needed to describe properly the contribution of genetic disorders to infant mortality.