Familial hypobetalipoproteinemia in pediatric patients with fatty liver: an under-recognized cause

Introduction: Fatty liver is a leading cause of chronic liver disease in children, most often due to metabolic dysfunction-associated steatotic liver disease (MASLD). Fatty liver in lean or younger children may indicate underlying metabolic or genetic disorders, such as familial hypobetalipoproteinemia (FHBL). We examined the importance of considering familial hypobetalipoproteinemia (FHBL) in children presenting with fatty liver. Methods: This case series includes seven patients with FHBL from three families, treated at two medical centers. Clinical, laboratory, imaging, and genetic data were collected from the medical records. Results: . The median follow-up (FU) time was 12 months (interquartile range [IQR]: 1-57 months). Liver enzymes were elevated in three patients (range: 50-300 IU/L); median aspartate aminotransferase and alanine aminotransferase levels were 30 IU/L (IQR: 26-40.75) and 32 IU/L (IQR: 24.5-74), respectively. The median triglyceride, low-density lipoprotein, and apolipoprotein B levels were 74 mg/dL (IQR: 62-125), 55.3 mg/dL (IQR: 30-84.5), and 39.5 mg/dL (IQR: 35.2-43), respectively. Conclusion: FHBL should be considered a potential diagnosis in children with fatty liver and may coexist with other contributing etiologies such as obesity.