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Mortality in babies with achondroplasia: revisited
Kristen Simmons1, S Shahrukh Hashmi, Angela Scheuerle
1Pediatric Research Center, Department of Pediatrics, University of Texas Medical School at Houston, Houston, Texas.
Insights
Mortality in children with achondroplasia remains high, particularly in infancy, despite some improvements. Further research is needed to assess long-term survival impacts of interventions for this genetic condition.
Area of Science:
- Genetics and genomics
- Pediatric health
- Public health and epidemiology
Background:
- Previous studies 30 years ago indicated higher mortality in children with achondroplasia, leading to recommendations for improved care.
- This study aimed to re-evaluate achondroplasia mortality rates in recent decades.
Purpose of the Study:
- To determine if mortality rates for children with achondroplasia have changed over the past few decades.
- To compare current mortality data with historical data and general population rates.
Main Methods:
- Identified 106 children born with achondroplasia in Texas (1996-2003) using the Birth Defects Registry.
- Matched birth data with death certificates through 2007.
- Calculated crude and standardized infant and overall mortality rates.
Main Results:
- Four deaths occurred within the first year of life, yielding an infant mortality rate of 41.4/1000 live births.
- Standardized infant mortality was higher when compared to the 2005 U.S. population (SMR2005: 6.02) than the 1975 population (SMR1975: 2.58).
- The SMR2005 was significantly higher than the SMR1975, indicating a potential discrepancy in mortality trends.
Conclusions:
- While overall mortality has improved, especially after infancy, children with achondroplasia still face significantly higher mortality risks than the general population.
- The higher standardized mortality ratio in 2005 compared to 1975 suggests a divergence in survival trends.
- Longer follow-up is necessary to ascertain the impact of interventions on long-term survival in achondroplasia patients.
Background:
Natural history studies performed 30 years ago identifying higher mortality among children born with achondroplasia, a genetic dwarfing condition, resulted in clinical recommendations aimed at improving mortality in childhood. The objective of this study was to determine if mortality rates have changed over the past few decades.
Methods:
Children born with achondroplasia during 1996 to 2003 were ascertained from the Texas Birth Defects Registry and matched with death certificate data from the Bureau of Vital Statistics through 2007. Infant and overall mortality rates, both crude and standardized to the 2005 (SMR2005 ) and 1975 (SMR1975 ) U.S. populations, were calculated.
Results:
106 children born with achondroplasia were identified. Four deaths were reported, with all occurring in the first year of life (mortality rate: 41.4 /1000 live-births). Infant mortality was higher when standardized to the 2005 U.S. population (SMR2005 :6.02, 95% CI:1.64-15.42) than the 1975 population (SMR1975 :2.58, 95% CI:0.70-6.61).
Conclusion:
The higher SMR2005 compared with SMR1975 , along with the fact that SMR1975 was nearly half that of a previous cohort reported 25 years ago (rate ratio: 0.53, 95% CI: 0.11-2.25), reflect a discrepancy in the changes in mortality in the overall population and in our cohort. Although an overall improvement in mortality, especially after the first year of life, is observed in our cohort, children with achondroplasia are still at a much higher risk of death compared with the general population. A longer follow-up is needed to elucidate whether evaluation/intervention changes have resulted in significant improvement in long-term survival among these patients.
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