Infant Mortality associated with Inborn Errors of Metabolism: a study based on Sudden Death

Presented By:

de Bitencourt, F.H.1; Vianna, F.S.L.2; Schwartz, I.V.D.3

1 Msc in Medical Science, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil. Affiliation: Postgraduated Program in Genetics and Molecular Biology, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil

2 PhD in Genetics and Molecular Biology, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil. Affiliation: Bioethical Service, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil and

3 PhD in Science: Genetics, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil. Affiliation:  Genetics Department,  Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil and Medical Genetics Service,  Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil

Corresponding author:

 

Ida Vanessa Doederlein Schwartz

Medical Genetics Service

Hospital de Clínicas de Porto Alegre

Rua Ramiro Barcelos 2350

90035-003 – Porto Alegre – RS

Brazil

Tel:  +555133598011

Fax:  +555133598010

Email: ischwartz@hcpa.edu.br

Abstract: Sudden unexpected death in infancy (SUDI) is one of the most frequent causes of death during the first year of life after the neonatal period. Literature points out that 0.9% to 6% of children who die unexpectedly may suffer from some metabolic disorder. A recent systematic review showed that at least 43 inborn errors of metabolism (IEM) are associated with sudden death, with the most commonly associated IEM being medium chain acyl-CoA dehydrogenase deficiency (MCADD). Fatty acid oxidation defects (FAOD) are not included in the Brazilian National Neonatal Program. Despite the decline in Brazil, infant mortality remains a major concern in Public Health. The infant mortality rate in Brazil (14.1:1,000 live births) is considered high and incompatible with a developed country.

Objectives: to estimate and characterize infant mortality associated with IEM in Brazil through data analysis from the Mortality Information System (SIM), a vital information system managed by the Ministry of Health.

Methodology: cross-sectional population-based study with information from SIM. From 2002 and 2014, all death records of children under one year of age, in which the cause of death, coded by ICD10 (International Classification of Disease and Related Health Problems), was: ICD10-E70 (disorders of amino acid metabolism), ICD10-E71 (disorders of branched-chain amino acid metabolism and fatty acid metabolism), ICD10-E72 (other disorders of amino acid metabolism), and ICD10-E74 (other disorders of carbohydrates metabolism) were selected.

Results:

From 2002 to 2014, 199 children under one year of age died from IEM (median of 17 deaths per year). Of those, 18 (9.0%) occurred in the North region of Brazil, 43 (21.6%) in the Northeast, 80 (40.2%) in the Southeast, 46 (23.1%) in the South, and 12 (6.0%) in the Central-West region. In all regions, death by ICD10-E74 was the most frequent (80 cases; 32.2% of registries). On the other hand, ICD10-E71 was the less frequent. The national infant death rate for selected IEM in the period was 0.067 per 1,000 live births, with the South region rate being 0.12; the Southeast 0.068; the Central-West 0.049; the Northeast 0.052; and the North 0.056 per 1,000 live births.

Conclusions: This is the first study to evaluate the relationship between sudden death and IEM in Brazil. The low death rate found may not suggest the rarity of IEM, but the underreporting of cases. Although 1 to 3% of sudden deaths in neonates are associated with FAOD, ICD10-E71 was the less frequent. This may demonstrate the underdiagnosis of this group of diseases,. Studies on infant mortality rate are fundamental for the development of health surveillance actions and for the decision-making process in order to subsidize the formulation procedure of public policies and to evaluate their results and impacts.