Clinical exome sequencing elucidates underlying cause of death in sudden unexpected death of infants: two case reports

Sudden unexpected death in infants (SUDI) is a traumatic event for families, and unfortunately its occurrence remains high in many parts of the world. Whilst cause of death is resolved for most cases, others remain undetermined following postmortem investigations. There has been a recognition of the role of genetic testing in unexplained cases, where previous studies have demonstrated the resolution of cases through DNA analyses. Here we present two case reports of SUDI cases admitted to Salt River Mortuary, South Africa, and show that underlying causes of death were determined for both infants using clinical exome sequencing. The first infant was heterozygous for a variant (rs148175795) in COL6A3, which suggested a bronchopulmonary dysplasia phenotype. This hypothesis led to finding of a second candidate variant in DMP1 (rs142880465), which may contribute towards a digenic/polygenic mechanism of a more severe phenotype. Histological analysis of retained tissue sections showed an asphyxial mechanism of death, where bronchiolar muscle weakness from an underlying bronchopulmonary dysplasia may have contributed to the asphyxia by affecting respiration. In the second infant, a homozygous variant (rs201340753) was identified in MASP1, which was heterozygous in each parent, highlighting the value of including parental DNA in genetic studies. Whilst mannose-binding lectin deficiency could not be assessed, it is plausible that this variant may have acted in combination with other risk factors within the triple-risk model to result in sudden death. These results may have genetic implications for family members, and represent possible new candidate variants for molecular autopsies.

Investigating blood alcohol concentrations in injury- related deaths before and during the COVID-19 national lockdown in Western Cape Province, South Africa: A cross-sectional retrospective review

BACKGROUND

Alcohol is a significant contributor to injury-related morbidity and mortality in South Africa (SA). During the COVID-19global pandemic, restrictions to movement and to legal access to alcohol (i.e. ethanol) were introduced in SA.

OBJECTIVES

To investigate the effect of alcohol bans during the COVID-19 lockdown periods on injury-related mortality and blood alcoholconcentrations (BACs) in these deaths.

METHODS

A retrospective, cross-sectional analysis of injury-related deaths in Western Cape Province (WC), SA, between 1 January 2019 and31 December 2020 was conducted. Cases where BAC testing was performed were further examined according to the periods of lockdownand alcohol restrictions.

RESULTS

A total of 16 027 injury-related cases were admitted to Forensic Pathology Service mortuaries in the WC over the 2-year period. Anaverage decrease of 15.7% injury-related deaths in 2020 compared with 2019 was noted, as well as a 47.7% decrease in injury-related deathsduring hard lockdown (April - May 2020) compared with the same period in 2019. In the injury-related deaths, 12 077 (75.4%) had bloodspecimens collected for BAC testing. In 5 078 (42.0%) of submitted cases, a positive BAC (≥0.01 g/100 mL) was reported. No significantdifference was observed in the mean positive BAC between 2019 and 2020. However, in April and May 2020, the mean BAC observed(0.13 g/100 mL) was less than that in 2019 (0.18 g/100 mL). A high number of positive BACs in the 12- 17-year age group (23.4%) was observed.

CONCLUSION

There was a clear decrease in injury-related deaths in the WC during the COVID-19-related lockdown periods, whichcoincided with the alcohol ban and restriction of movement, and an increase following relaxation of restrictions on alcohol sales andmovement. The data illustrate that mean BACs were similar between all periods of alcohol restriction compared with 2019, apart from hardlockdown in April - May 2020. This coincided with a smaller mortuary intake during the level 5 and 4 lockdown periods.

Investigating blood alcohol concentrations in injury-related deaths before and during the COVID-19 National lockdown in Western Cape, South Africa: A cross-sectional retrospective review

BACKGROUND

Alcohol is a significant contributor to injury-related morbidity and mortality in South Africa (SA).  During the COVID-19 global pandemic, restrictions to movement and to the legal access of alcohol* were introduced in SA.  This study aimed to investigate the effect of alcohol bans during the COVID-19 lockdown periods on injury-related mortality and the blood alcohol concentrations (BAC) in these deaths.

METHODS

A retrospective, cross-sectional analysis of injury-related deaths in Western Cape (WC) province, SA, between 1 January 2019 to 31 December 2020 was conducted. Cases where BAC testing was performed were further examined according to the periods of lockdown (AL5-1) and alcohol restrictions.

RESULTS

A total of 16,027 injury-related cases were admitted to Forensic Pathology Service mortuaries in the WC over the two-year period.  An average decrease of 15.7% injury-related deaths in 2020 compared to 2019 was noted, as well as a 47.7% decrease in injury-related deaths during hard lockdown (April -May 2020) compared to the same period in 2019. In the injury-related deaths, 12,077 (75.4%) had blood specimens collected for BAC testing. In 5,078 (42.0%) of submitted cases, a positive BAC (≥0.01g/100 mL) was reported. No significant difference was observed in the mean positive BAC between 2019 and 2020, however in April and May 2020, the mean BACs observed (0.13 g/100 mL) was less than that in 2019 (0.18 g/100 mL). A high number of positive BACs in the 12-17-year age group (±23.4%) was observed.

CONCLUSION

There was a clear decrease in injury-related deaths in the WC during the COVID-19-related lockdown periods that coincided with the alcohol ban and restriction of movement and an increase following relaxation of restrictions on alcohol sales and movement. The data illustrated that mean BACs were similar between all periods of alcohol restriction compared to 2019, apart from hard lockdown in April-May, 2020.  This coincided with a smaller mortuary intake during the level 5 and 4 lockdown periods.   Keywords: Alcohol; blood alcohol concentration; COVID-19; injury; lockdown; South Africa; violent death; Western Cape   * Alcohol refers to ethanol.