A 3'-truncating FTL mutation associated with hypoferritinemia without neuroferritinopathy

Area of Science:

• Genetics
• Neurology
• Biochemistry

Background:

• Mutations in the ferritin light chain (FTL) gene are typically linked to hypoferritinemia and progressive extrapyramidal dysfunction.
• Some FTL mutations may affect ferritin levels without causing neurological symptoms, a phenomenon not fully understood.

Observation:

• A three-generation family presented with autosomal dominant hypoferritinemia but no signs of neurodegeneration.
• The proband and affected relatives exhibited longstanding hypoferritinemia, normal iron levels, and no anemia or iron deposition in brain MRI.
• Over a nine-year follow-up, no family members developed neurological dysfunction, including movement disorders or psychiatric issues.

Findings:

• Whole exome sequencing identified a heterozygous interstitial deletion in the FTL gene (19q13.33, involving exons 3 and 4) in all affected individuals.
• This deletion is predicted to result in a significantly truncated FTL protein product.
• The findings suggest that FTL haploinsufficiency can lead to hypoferritinemia without associated neurological impairment.

Implications:

• This research expands the known phenotypic spectrum of FTL mutations.
• It highlights that FTL haploinsufficiency is a potential cause of isolated hypoferritinemia.
• Further studies are warranted to elucidate the mechanisms underlying the absence of neurological symptoms in these cases.