What else is it called?

  • AKU
  • Black Bone Disease

Get in touch

Contact our caring team on 08452 412 173 for help and support. Our phone lines open 10am-4pm, Monday to Friday.

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What causes it?

AKU is a rare genetic metabolic disorder caused by a mutation of one chromosome that stops patients’ bodies from breaking down a chemical called homogentisic acid (HGA) which the body naturally produces during the digestion of food. Due to this, HGA builds up and leads to black and brittle bones and cartilage.

How common is it?

AKU affects between one in 250,000 to 500,000 people.

What are the signs and symptoms?

Signs and symptoms include black urine, osteoarthritis, black spots in the eyes, discolouration of the ears, and heart complications.

How is it diagnosed?

AKU is diagnosed upon the identification of characteristic symptoms such as dark urine, high levels of homogentisic acid in the urine, and osteoarthritis.

Can it be treated?

Nitisinone treatment effectively reduces the level of homogentisic acid in the body, halting the progression of the disease.

Do my family need to be tested?

AKU is caused when a child inherits two copies of the faulty HGA gene (one from each parent). The parents of a person with AKU will often only carry one copy of the faulty gene themselves, which means they will not have any signs or symptoms of the condition.

A family history of AKU is consistent with a child being born with AKU, however a lack of known family history does not preclude the diagnosis.

Relevant Organisations

The information on this page has been kindly provided by our friends at the AKU Society.

The AKU Society is a patient-led support group. We work to improve the lives of those with alkaptonuria (AKU) and those who support them while researching for a cure.

The AKU Society contact details:

Phone: 01223 322897



Social Media handles:

Twitter: @AKUSociety

Instagram: @akusociety

Facebook: @AKUSOCIETY LinkedIn:


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