Hyperferritinemia, hereditary, with congenital cataracts

Hereditary Hyperferritinemia with Congenital Cataracts (HHCC) is a genetic disorder characterized by an elevated level of ferritin in the blood without an increase in body iron stores and the early onset of cataracts. Ferritin serves as an intracellular iron storage protein, and its levels in the blood typically reflect the total amount of iron stored in the body. However, in HHCC, ferritin levels are disproportionately high due to a mutation affecting its regulation, not because of increased iron levels.

Causes

HHCC is caused by mutations in the FTL gene, which encodes the ferritin light chain. The mutations lead to a change in the iron-responsive element (IRE) in the 5' untranslated region of the FTL mRNA. Normally, the IREs regulate ferritin synthesis in response to iron levels, but mutations disrupt this regulation, leading to excessive ferritin production.

Symptoms

The hallmark symptoms of HHCC are the early development of cataracts, which can occur in childhood or early adulthood, and elevated serum ferritin levels. Unlike other conditions associated with high ferritin levels, patients with HHCC typically do not have iron overload in organs such as the liver. Other symptoms may vary and can include liver dysfunction in some cases.

Diagnosis

Diagnosis of HHCC involves a combination of clinical observation and laboratory tests. Key diagnostic criteria include:

• Elevated serum ferritin levels without signs of iron overload
• Early onset of cataracts
• Family history consistent with autosomal dominant inheritance
• Genetic testing confirming mutations in the FTL gene

Treatment

Treatment for HHCC primarily focuses on managing symptoms. Cataract removal is the most common treatment to restore vision. There is no specific treatment required for the hyperferritinemia as it does not reflect an actual iron overload condition. Patients are advised to undergo regular monitoring for any potential complications arising from elevated ferritin levels or liver function abnormalities.

Epidemiology

HHCC is a rare condition, with cases reported worldwide. The exact prevalence is unknown. It follows an autosomal dominant pattern of inheritance, meaning a single copy of the mutated gene in each cell is sufficient to cause the disorder.

See Also

• Ferritin
• Cataracts
• Genetic disorders
• Iron metabolism disorders