Long chain fatty acid oxidation disorders (LCFAOD) are a broad group of genetic diseases characterized by defects in the carnitine shuttle or mitochondrial beta-oxidation enzymes, impeding the body’s ability to convert long chain fatty acids into energy. 

The pathological build-up of metabolites can affect several organs, such as the eyes, nervous system, and the heart. In addition, prolonged energy deficiency can cause problems such as rhabdomyolysis and hypoglycemia.

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Patients with LCFAOD often suffer from periodic crises stemming from severe energy deficiency, which typically takes place during periods of illness, physiological stress, and fasting. Patients with LCFAOD often describe feelings of fatigue and exercise intolerance. 

“Symptom presentation is often punctuated by episodes of acute, life-threatening, unpredictable, and precipitous decompensation, regardless of current disease status, age, or type, and can have a detrimental impact on patients’ quality of life,” Williams-Hall and colleagues wrote in Therapeutic Advances in Endocrinology and Metabolism. 

Shining a Spotlight on Quality of Life 

When it comes to chronic conditions such as LCFAOD, all roads lead to issues surrounding quality of life, both of the patients themselves and of their caregivers. 

In a study published in Molecular Genetics and Metabolism Reports, Kruger and colleagues conducted a study to understand how the disorder impacts activities of daily living. They created an online survey consisting of items pertaining to how LCFAOD affects performance at school/work, physical activities, and mental health. Adult patients with LCFAOD (n=14) and caregivers who have cared for at least one individual with LCFAOD (n=30) were invited to fill in the survey. 

The results demonstrated that the disease had notable impacts on the ability of patients and their carers to study/work; 59.2% reported some negative impact on their schooling, while 70% of parents who had children with LCFAOD reported some negative impact on their work. In addition, both adults with LCFAOD and parents of children with LCFAOD reported missing a higher number of work days than the general population. 

“When looking at physical and mental component scores, individuals with LCFAOD reported significantly lower [physical component scores] and [mental component scores] than a control group of representative Americans,” Kruger et al wrote. 

This study illustrates the various challenges that a diagnosis of LCFAOD can impose on patients and their caregivers; respondents of the survey described how increased hospitalization, emergency visits, and doctor’s appointments limit their ability to participate fully in activities of daily living. In addition, the survey revealed that different individuals can have different experiences with the illness; for example, children tend to be more affected by hypoglycemia than adults, while adults tend to be more impacted by rhabdomyolysis. 

Read more about LCFAOD prognosis 

This study’s results closely echo that of another conducted by Williams-Hall and colleagues. To understand the lived experiences of patients of LCFAOD and their caregivers, they held a focus group in which patients (n=4) and caregivers (n=4) were allowed to express their daily struggles in dealing with this disease. The research team also conducted semi structured and structured interviews with study participants. 

Williams-Hall and colleagues reported that patients described recurring episodes of ill health, termed “acute symptom episodes” or “metabolic crises.” These occur once or twice a year and often result in hospital stays stemming from triggers such as infection, stress, hormonal changes, and prolonged exercise. Patients who were educated about these potential triggers were better equipped to avoid them. 

In addition, participants expressed how the disease resulted in their having to make tough choices regarding lifestyle modification, which negatively impacted their social and physical function, work/school, and emotional/psychological well-being. 

Our Role as Clinicians 

Both studies quoted above arrived at similar conclusions: LCFAOD significantly impacts patients’ sense of well-being, and the disease burden is often shared to a considerable extent by caregivers as well. 

We as clinicians must learn to associate certain symptoms with specific quality-of-life outcomes. Take rhabdomyolysis, for example; muscle breakdown typically reduces physical function and mobility, which means fewer opportunities to participate in sports and exercise. And because there is often a social component to sports and exercise, the loss of participation in these activities can trigger feelings of isolation, resulting in poorer psychological health. 

In addition, we should also recognize that each patient’s experience is different and that care should be tailored toward each patient’s set of symptoms and the frequency/severity of acute crises experienced. We should also pay attention to our patients’ psychological complaints to ensure they are cared for holistically. 

“Future research should aim to explore the patient experience of LCFAOD in a more demographically and clinically diverse sample,” Williams-Hall and colleagues wrote. “This may further generate an understanding of the unmet needs and considerations for the ongoing management of LCFAOD, in addition to their longitudinal effects on patients’ symptoms, [quality of life], and mortality.”


Kruger E, Voorhees K, Thomas N, et al. Understanding the impact of long-chain fatty acid oxidation disorders for patients and caregiversMol Genet Metab Rep. Published online August 10, 2022. doi:10.1016/j.ymgmr.2022.100903

Williams-Hall R, Tinsley K, Kruger E, et al. Qualitative evaluation of the symptoms and quality of life impacts of long-chain fatty acid oxidation disordersTher Adv Endocrinol Metab. Published online January 10, 2022. doi:10.1177/20420188211065655