Novel manifestations of Farber disease mimicking neuronopathic Gaucher disease

Diagnosis of rare disorders requires heightened clinical acumen. When such disorders present with atypical or novel features, it adds to the diagnostic challenge. A 9-month-old female infant who had received a diagnosis of neonatal hepatitis due to cytomegalovirus infection at 2 months of age presented to our institute with developmental delay, fever, vomiting, feeding difficulty, breathlessness and features of elevated intracranial pressure due to hydrocephalus. Key examination findings with cholestatic jaundice as an early manifestation led to suspicion of type 4 Farber disease. Observation of hydrocephalus, hypertension, bilateral pinguecula and Erlenmeyer flask deformity of the femur were unusual findings for Farber disease. The child had few features (pinguecula, Erlenmeyer flask deformity and hydrocephalus) overlapping with Gaucher disease. Alternatively, prosaposin deficiency (Farber disease type 7) was another differential diagnosis. Diagnosis of Farber disease was confirmed by detection of foamy macrophages on skin biopsy and two homozygous missense variants in ASAH1 gene.