A novel mutation in an atypical presentation of the rare infantile Farber disease

Background: Farber disease (MIM 228000) is a rare autosomal recessive condition caused by deficiency of lysosomal acid ceramidase (EC 3.5.1.23). The disease presents classically during the infantile period with a characteristic triad of clinical manifestations: (a) painful joints, (b) subcutaneous nodules, and (c) progressive hoarseness due to laryngeal involvement. All cases reported in the literature to date have presented with the above features, except for the neonatal-visceral subtype. Methods: Here we describe a 2-year-old female, a product of a non-consanguineous Emirati union, who was quite well until 8 months of age when presented with failure to thrive, developmental delay with relative sparing of cognitive function, cherry-red spot, painful joint, progressive limitation of joint movement, and hoarseness of voice. The sibling of patient died with similar presentation and the nerve biopsy of deceased sibling showed features consistent with Farber disease. Results: Gene sequencing of the ASAHI gene confirmed the diagnosis of Farber disease. Our patient has two heterozygous novel mutations, one in exon 8 (c.533 T > C) and the other in exon 13 (c.1144 A > C). The carrier status of the parents was confirmed. Conclusions: Farber disease is well known for its striking unique triad of symptoms. This study demonstrates that not all the cases essentially present with subcutaneous nodules which is considered a hallmark of the disease.