Sudden unexpected death in infancy (SUDI)
- 1Department of Clinical Chemistry, Belfast City Hospital, Lisburn Road, Belfast BT9 7AB, UK
- 2Department of Clinical Chemistry, West Midlands Regional Laboratory for Neonatal Screening and Inherited Metabolic Disorders, Diana, Princess of Wales Hospital, Birmingham B4 6NH, UK
- 3Department of Clinical Chemistry, West Midlands Regional Laboratory for Neonatal, Screening and Inherited Metabolic Disorders
- Correspondence to: Dr C M Loughrey Department of Clinical Chemistry, Belfast City Hospital, Lisburn Road, Belfast, BT9 7AB, UK; clodagh.loughreybll.n-i.nhs.uk
- sudden infant death syndrome
- sudden unexpected death in infancy
- metabolic
- autopsy
- tandem mass spectrometry
Rigorous metabolic investigation is essential
Sudden infant death syndrome (SIDS) risk reduction campaigns have resulted in a significant decline in the incidence of SIDS.1 However, SIDS remains the major single cause of death in children in developed countries, with a reported incidence, together with unascertained deaths, of approximately 1/3000 live births.1,2
SIDS is in essence a diagnosis of exclusion, although there are inconsistencies in how it is applied, and some pathologists feel that it is not adequately defined.3,4 In a study of the various causes of sudden unexpected death in infancy (SUDI), the most common non-SIDS diagnosis was infection (7.1% of 623 cases), followed by cardiovascular anomaly (2.7%), child abuse (2.6%), and metabolic/genetic disorders (2.1%).5 Cardiovascular defects and serious infection are potentially easier to diagnose at necropsy than many of the inherited metabolic disorders that may contribute to SUDI. Importantly, it was noted that a non-SIDS diagnosis was reached much more frequently in centres with expertise in paediatric pathology (18% v 6%).5 Therefore, inherited metabolic disorders (IMDs) or other genetic disorders may be underdiagnosed as a cause of SUDI in less specialist centres. IMD as a cause of SUDI will probably constitute a greater proportion of all cases of SUDI as the incidence of total SUDI falls, partly because of a decline in the incidence of other causes of SUDI, and possibly more consistent application of the diagnostic criteria for SUDI; however, an important factor will be improved detection of the various metabolic causes of SUDI.
“Inherited metabolic disorders or other genetic disorders may be underdiagnosed as a cause of sudden unexplained death in infancy in less specialist centres”
Where SUDI occurs in more than one …
