Brittle cornea syndrome (BCS)

Please note: The following text cannot and should not replace advice from the patient's healthcare professional(s). Any person who experiences symptoms or feels that something may be wrong should seek individual, professional help for evaluation and/or treatment. This information is for guidance only and is not intended to provide individual medical advice.

What is BCS?

BCS is an incredibly rare type of EDS and causes individuals cornea’s to be thin and fragile.

What is the cause of BCS?

BCS is caused by variations in a person’s genes. BCS is caused by variations in genes ZNF469 or PRDM5.

How is BCS diagnosed?

When diagnosing BCS a list of common and relevant signs and symptoms of the condition are used. This is referred to as diagnostic criteria and in the case of BCS it is split into a set of major and minor criteria.

The Major criteria

1. Thin cornea, with or without rupture
2. Early onset progressive keratoconus
3. Early onset progressive keratoglobus
4. Blue sclerae

The Minor criteria

1. Enucleation or corneal scarring as a result of previous rupture
2. Progressive loss of corneal stromal depth, especially in central cornea
3. High myopia, with normal or moderately increased axial length
4. Retinal detachment
5. Deafness, often with mixed conductive and sensorineural components, progressive, higher frequencies often more severely affected (“sloping” pure tone audiogram),
6. Hypercompliant tympanic membranes
7. Developmental dysplasia of the hip
8. Hypotonia in infancy, usually mild if present
9. Scoliosis
10. Arachnodactyly
11. Hypermobility of distal joints
12. Pes planus, hallux valgus
13. Mild contractures of fingers (especially 5th)
14. Soft, velvety skin, translucent skin

To meet the diagnostic criteria for BCS a person must have:

Major criteria 1 (thin cornea, with or without rupture)

plus

Either: at least one other major criterion

And/or three other minor criteria

If a person meets the criteria a genetic test is done to confirm the diagnosis. You can read more about genetic testing for the rare types of EDS here.

How is BCS managed?

BCS is managed through addressing the symptoms a person is experiencing. This is best done through being in the care of the NHS National EDS service; a specialised service for adults and children who have or are suspected to have a rare type of EDS.

For information about the service and for referral eligibility please click on the following links:

EDS National Diagnostic Service (based in London) covering the South of England

EDS National Diagnostic Service (based in Sheffield) covering the North of England