Brittle Cornea Syndrome

Brittle Cornea Syndrome (BCS) is a rare autosomal recessive disorder with biallelic mutations on either ZNF469 (type 1) or PRDM5 (type 2). BCS's main impact is the eye with the diagnosis requires molecular testing.

The minimal criteria required to suggest BCS is the presence of the first major criteria in addition to any other major criteria; or three minor criteria. Molecular testing is required to confirm a diagnosis.

Major Criteria

1. Thin cornea, with or without rupture (central corneal thickness often <440um);

2. Early-onset progressive keratoconus;

3. Early-onset progressive keratoglobus; and

4. Blue sclerae

As the name suggests this variant of EDS involves the eye. With a risk of ruptures to the cornea following minor injury which causes scarring. Patients may have blue sclera.

Minor Criteria

1. Enucleation or corneal scarring as a result of previous ruptures;

2. A progressive loss of corneal stromal depth, especially in the central cornea;

3. High myopia, with normal or moderately increased axial length;

4. Retinal detachment;

5. Deafness, of with a mix of conductive and sensorineural components, progressive, higher frequencies often more severely affected;

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;

14. Sof, velvety skin, translucent skin.

For more information see The Ehlers-Danlos Society

References

The 2017 International Classification of the Ehlers–Danlos Syndromes