Mevalonic Aciduria Associated with Intrahepatic Bile Duct Paucity

An 11-day-old Mennonite boy with consanguineous (8°) parents and unremarkable prenatal course presented with jaundice, failure to thrive, hypotonia, and dysmorphic features (Figure 1A). His biochemical abnormalities included anemia, increased inflammatory markers, and transaminitis (Table 1). Normal work-up included: liver ultrasound, serum alpha-1 antitrypsin, ammonia, venous blood gas, plasma amino acids, international normalized ratio, albumin, glucose, thyroid stimulating hormone, newborn screen, and chromosomal microarray. Extensive infectious workup was negative. Head MRI showed ependymal cysts along the lateral walls of the lateral ventricles. Abdominal ultrasound showed grade 1 left hydronephrosis. He had no butterfly vertebra. Ophthalmologic examination was unremarkable. Echocardiogram showed a moderate atrial septal defect and interrupted inferior vena cava with azygous continuation.