Genetics

Farber Disease | Common Symptoms | Treatment and Management | Genetics

Genetics of Farber Disease and ASAH1-Related Conditions

DNA is the genetic information in our body that gives instructions for how the body grows and functions. This information is packaged into genes. Genes are inherited from parents and give instructions to cells. There are two copies of the ASAH1 gene in every cell of the body; one copy each is received from each parent. If the genes have a pathogenic variant, or mutation, the instructions may be missing or not work correctly, and this may cause a genetic disease. 

Farber disease is an ultra-rare autosomal recessive genetic condition caused by pathogenic variants in the ASAH1 gene.

Farber disease is an autosomal recessive condition1.

This means:

  • If BOTH copies of a person’s ASAH1 gene have a variant causing disease, they will have an ASAH1-related disorder. 
  • If ONE copy has a variant, they will be a carrier of the disease. Carriers do not have any symptoms but can pass the disease onto their children. 
  • If BOTH parents are carriers of an ASAH1 variant, each of their children will have a 25% chance of having the disease, a 50% chance of being a carrier, and a 25% chance of not having the disease or being a carrier.

A genetic counselor or geneticist may help families obtain a diagnosis or learn more if an ASAH1 variant is suspected. Genetic counselors can help individuals and families make informed decisions by sharing information on the nature, inheritance patterns, and implications of genetic disorders.

ASAH1 variants make it difficult for acid ceramidase enzymes to work like they should, which leads to complications and symptoms of Farber disease.

SMA-PME: An ASAH1-Related Condition

Farber disease is part of a group of disorders that are characterized by pathogenic variants in the ASAH1 gene. A related condition is Spinal Muscular Atrophy with Progressive Myoclonic Epilepsy (SMA-PME)2. 

People living with Farber disease and SMA-PME have the same enzyme deficiency but the first symptoms that appear may be different. With either diagnosis, the ASAH1-related condition may progress, resulting in “overlapping” symptoms that impact a broad range of organ systems throughout the body3. 

Most common first symptoms: 

Explore more about Farber disease

About Farber Disease
Common Symptoms
Treatment and Management

References

1 Farber disease | Genetic and Rare Diseases Information Center (GARD) – an NCATS Program. rarediseases.info.nih.gov.

2 Zhou J, Tawk M, Tiziano FD, Veillet J, Bayes M, Nolent F, Garcia V, Servidei S, Bertini E, CastroGiner F, Renda Y, Carpentier S, Andrieu-Abadie N, Gut I, Levade T, Topaloglu H, Melki J. Spinal muscular atrophy associated with progressive myoclonic epilepsy is caused by mutations in ASAH1. Am J Hum Genet. 2012 Jul 13;91(1):5-14. PMID: 22703880.

3 Yu FPS, Amintas S, Levade T, Medin JA. Acid ceramidase deficiency: Farber disease and SMA-PME. Orphanet Journal of Rare Diseases. 2018;13(1). doi:10.1186/s13023-018-0845-z.

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