Author: Sara Habibipour
Down syndrome (DS) is the most common liveborn genetic chromosomal disorder. Over the past several decades, a significant increase has been reported in life expectancy for those with Down syndrome. However, this rise in life expectancy is not equal for all racial groups.
Quenhe Yang, PhD and colleagues reviewed nearly 18,000 cases of people living in the United States with Down syndrome from 1983-1997 and noted significant differences in race and life expectancy:
These trends persist even accounting for the presence of congenital heart disease, which is a common comorbidity of DS. Data show that improvement in mortality and increased survival over the past decades is seen in individuals with DS of all races, but less so in African-Americans. And, although differences in life expectancy are seen among the United States population as a whole, the racial disparity is larger in the DS population.
Why is this the case?
Medical histories of 763 children receiving medical care at a DS specialty clinic in Cincinnati from 1984-2009 were reviewed to try and find an underlying association related to racial disparity and mortality due to DS. Patterns related to maternal drug use, hyperbilirubinemia, and intubation were found, however could not be determined as the cause of mortality.
The research group also noticed significant increases in referrals to Cardiology for Black children compared to white children, perhaps indicating more severe congenital cardiac conditions among Black children. Outcomes in congenital cardiac care are also known to be dependent upon racial group; read more about how social determinants of health impact congenital heart care in our recent article here.
Although it is clear that disparities in DS outcomes and life expectancy exist, the research group could not conclude the underlying cause of this disparity. Likely, it is due to a plethora of factors ranging from socioeconomic status, insurance, the transition from pediatric to adult care, ability to afford medication and being able to manage the care of a person living with Down syndrome and its comorbidities etc. rather than (or, at least, in combination with) a physical, medical, or genetic explanation; these factors would likely be difficult to assess solely via medical records, so more qualitative research, taking into greater account the social determinants of health, is needed in order to link associations between racial group and disparities in DS outcomes.
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Sources:
https://pubmed.ncbi.nlm.nih.gov/11937181/
https://pubmed.ncbi.nlm.nih.gov/37244582/