C9orf72 expansion presenting as an eating disorder

Area of Science:

• Neuroscience
• Genetics

Background:

• Behavioral variant frontotemporal dementia (bvFTD) is a neurodegenerative disorder.
• The C9orf72 gene is a known genetic cause of frontotemporal dementia and amyotrophic lateral sclerosis.

Observation:

• A 64-year-old woman with a family history of motor neuron disease presented with atypical symptoms including severe food restriction, low weight, disordered eating, and anxiety.
• Her initial presentation delayed the diagnosis of behavioral variant frontotemporal dementia.

Findings:

• Genetic testing revealed the patient was a carrier of the C9orf72 hexanucleotide repeat expansion.
• This case supports that C9orf72 mutations can lead to varied clinical syndromes.
• Anorexia and food refusal are identified as potential features of C9orf72-related disorders.

Implications:

• The C9orf72 mutation should be considered in patients with unexplained eating disturbances and neurological symptoms.
• Recognizing this expanded phenotype can aid in earlier diagnosis and management of C9orf72-related disorders.
• Further research into the phenotypic variability of C9orf72 expansions is warranted.