What is SIDS?
Sudden Infant Death Syndrome (SIDS) is the unexpected and unexplained death of an otherwise healthy baby under one year of age, typically during sleep. Despite decades of research, the exact cause of SIDS remains unknown. Experts believe that a combination of environmental, developmental, and biological factors may contribute. Increasingly, research is pointing toward potential connections between SIDS and underlying genetic or metabolic conditions.
October is recognized as SIDS Awareness Month, a time to increase understanding of this condition, support families who have experienced loss, and highlight the importance of research into potential causes and prevention strategies.
The Role of Metabolic Disorders
Some inherited metabolic disorders (conditions where the body cannot properly process certain fats, proteins, or sugars) can present suddenly and severely in newborns. If undiagnosed, these conditions may cause life-threatening low blood sugar, acid buildup in the body, or disruptions in energy production. In certain cases, what appears to be SIDS may actually be an undetected metabolic disorder.
Examples include:
- Fatty acid oxidation disorders (FAODs): Babies with these conditions cannot use stored fat for energy during fasting or illness, leading to dangerous hypoglycemia.
- Urea cycle disorders: These prevent the body from removing ammonia from the blood, which can cause lethargy, seizures, and sudden death.
- Organic acidemias: These can lead to toxic buildups that affect the brain and other organs.
How Newborn Screening Plays a Role
Fortunately, many of these metabolic disorders can be detected early through newborn screening (NBS). In the U.S. and many other countries, a heel-prick blood sample collected shortly after birth is tested for dozens of rare but serious genetic conditions. Early detection means early intervention—such as dietary changes, medications, or supplements—that can prevent life-threatening complications.
Newborn screening has already saved countless lives by identifying babies at risk before symptoms appear. However, not all possible metabolic or genetic conditions are included in every state or country’s screening panel. This means some infants with undiagnosed conditions could still be at risk.
Genetic Conditions and SIDS Risk
Beyond metabolic disorders, researchers are also exploring how certain genetic variations may contribute to SIDS risk:
- Cardiac arrhythmia genes (e.g., long QT syndrome): Mutations in heart rhythm genes can predispose infants to sudden cardiac arrest.
- Neurological genes: Some genetic changes may affect how the brain controls breathing and arousal during sleep.
- Immune system and infection response genes: Variations here may influence how an infant’s body reacts to common infections, potentially contributing to sudden death.
While these discoveries are still emerging, they highlight that SIDS may not be a single condition but rather the final common outcome of multiple possible underlying causes.
Who Should Consider Further Genetic Testing?
Families may want to consider additional genetic evaluation in situations such as:
- A history of SIDS or unexplained infant loss in the family.
- Sudden infant death where autopsy findings suggest possible metabolic or cardiac issues.
- Infants with concerning symptoms—such as recurrent seizures, unexplained low blood sugar, or unusual lab results—not explained by routine testing.
Moving Forward: Combining Research, Screening, and Counseling
While the “Back to Sleep” campaign and safe sleep guidelines have significantly reduced SIDS rates, unexplained cases still occur. The next frontier involves combining safe sleep practices with advances in genetics and newborn screening to identify hidden medical contributors.
At MKGenetix, we recognize the importance of bridging this gap. We can support families and healthcare providers by:
- Offering expanded genetic testing when there’s concern for underlying inherited conditions.
- Helping interpret newborn screening results.
- Providing counseling and resources for families with a history of unexplained infant loss.
Final Thoughts
SIDS remains a heartbreaking and complex diagnosis. While safe sleep practices are critical, understanding the role of genetics and metabolic disorders may uncover additional ways to protect infants. Newborn screening has already proven to be a powerful tool in preventing sudden and unexpected infant deaths, and expanding access to genetic testing may further reduce risks.
As our understanding grows, genetic counselors play an essential role in guiding families through the process—helping them understand results, options, and implications for their child’s health. If you have concerns about SIDS or a family history of unexplained infant loss, talk to your healthcare provider or a genetic counselor to explore whether further evaluation may be right for you.
Warm regards,
Megan Trinkle-Knotts, MS, CGC
Certified Genetic Counselor
Founder, MKGenetix
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