伊藤 哲哉

UNLABELLED: Propionic acidemia (PA) is a known cause of secondary dilated cardiomyopathy (DCM). However, little is known about how diet and heart failure treatment impact long-term cardiac outcomes in adult PA patients. We report the successful treatment of metabolic disease and secondary DCM-associated heart failure in a 20-year-old male patient with neonatal-onset PA and intellectual disability. At age 19 years, echocardiography had revealed DCM without impaired cardiac contractility. At age 20 years, he developed heart failure, presumably from a common cold infection, and was hospitalized. Acute heart failure treatment improved his symptoms, leading to discharge, but they worsened again, necessitating re-admission. He then was discharged only after successfully adding carvedilol and pimobendan to his medication. Six weeks later, however, he developed hyperammonemia with elevated serum propionyl carnitine and decreased free carnitine levels. He received acute phase treatment for this metabolic crisis and his diet therapy was readjusted, including by reducing natural protein. In the following 5 years, while continuing and slightly adapting heart failure medication and dietary regimens, the patient's cardiac function stably improved and his diuretic dose could be reduced. Our findings support that careful diet therapy and modulation of heart failure medication can improve cardiac function in PA patients with DCM. LEARNING OBJECTIVE: Neonatal-onset propionic acidemia (PA) tends to be the most severe form of PA and life-threatening metabolic disease. Even if the impact of the disease can be ameliorated by adapting the diet, later in life these patients often develop symptoms such as intellectual disability, metabolic crises, and dilated cardiomyopathy (DCM), as observed in this case. This case demonstrates that heart failure medication and dietary therapy can help protect against metabolic disease and DCM-associated heart failure in an adult patient with neonatal-onset PA.

Newborn screening (NBS) for Fabry disease (FD) is an effective way to identify individuals with FD before the onset of symptoms, enabling early therapeutic treatment. The classic form of FD typically begins in early childhood or later, but the late-onset form often develops in adulthood. However, FD-NBS identifies positive cases regardless of the expected timing of symptom onset. Consequently, concerns have been raised about prolonged uncertainty, medicalization, and caregivers' hypervigilance throughout the asymptomatic period. These issues are particularly salient for mothers, who are often heterozygous carriers and primary caregivers. Despite the growing implementation of FD-NBS in some countries, the perspectives of parents, especially mothers, have not been adequately explored. This study explores the experiences, emotions, and needs of five mothers whose children were diagnosed with FD through NBS, aiming to uncover the psychological impact and support required during the asymptomatic period. Semistructured interviews were conducted and analyzed using the KJ (Kawakita Jiro) method, a kind of bottom-up qualitative approach. The findings revealed that mothers experienced a psychological burden related to monitoring for disease onset. However, this burden was reduced by several factors, including an understanding of the timing of onset, the attending physician's opinions, the passage of time, and personalized coping strategies. Needs were identified for support in understanding the disease, as well as for spaces that facilitate empathy and information exchange. Opinions regarding FD-NBS were generally positive; however, negative feelings were also expressed, including views that they did not have to discover their child's FD through NBS. These findings suggest that understanding the experiences of mothers of asymptomatic children and providing support, such as genetic counseling and peer support, could enhance the effectiveness of FD-NBS.