A child who was normal at birth develops progressive growth failure, photosensitivity, and neurological regression. He has a characteristic cachectic appearance with sunken eyes.
AR; ERCC6 (CSB) or ERCC8 (CSA)
- Defective nucleotide excision repair (one of several DNA repair mechanisms)
- Postnatal growth failure (cachectic habitus)
- Photosensitivity (but NO increased skin cancer risk)
- Progressive neurological deterioration
- Sensorineural hearing loss
- Pigmentary retinopathy
- Dental caries
- Characteristic facies: sunken eyes, prominent ears
Overlap: Related to xeroderma pigmentosum (different repair pathway)
- Clinical recognition: postnatal growth failure, cutaneous photosensitivity, progressive neurologic decline, and cachectic facies
- Confirm with molecular testing of ERCC6 (CSB) and ERCC8 (CSA), typically via a multigene panel
- Supportive findings: cerebellar/cerebral atrophy with intracranial calcifications on MRI/CT, demyelinating peripheral neuropathy, and a DNA-repair (RNA synthesis recovery) cellular assay in selected cases
- Supportive, multidisciplinary care: nutrition and feeding support, physical/occupational therapy for contractures, and developmental support
- Strict photoprotection (sun avoidance, sunscreen); periodic ophthalmology (cataract, retinopathy) and audiology surveillance
- Monitor for and treat hypertension, renal dysfunction, dental caries, and tremor/spasticity; avoid metronidazole (reports of acute hepatic decompensation)
"CockayNE has defective NER": Cockayne syndrome is caused by defective nucleotide excision repair (NER), specifically transcription-coupled repair, in ERCC6 or ERCC8.
"C0CKAYNE": microCephaly (progressive), 0% centile for growth & 0% cancer risk, Kyphosis, Aging (premature), mYelination defect, Nucleotide Excision repair (ERCC6/8)
"Cockayne is Compact": Short stature and FTT.
ERCC in Cockayne: The letters ERCC are hidden inside "CockaynE syndRome, transCription-Coupled repair."