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12 Cards in this Set

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Clinical Cockayne Syndrome
Inheritance
Autosomal recessive; Cockayne syndrome group A (CSA): ERCC8 gene on chromosome 5

Cockayne syndrome group B (CSB): ERCC6 gene on 10q11
prenatal
Amniocentesis/amniotic fluid cell culture deficient RNA synthesis and increased c death after UV irradiation

DNA analysis
Incidence
Very rare; M=F;

CSB most common (80% of cases)
Age at Presentation
Birth to 2 years old; some later, into teens
Pathogenesis
Mutations in ERCC8 and ERCC6 impairs DNA repair in active genes specifically, rendering the patient hypersensitive to UV and leads to progressive neurodegeneration;

overlap of XPB, XPD, XPG with Cockayne exists in small number of patients
Clinical
Skin
Photosensitive eruption with erythema and scale in "butterfly" distribution on
face may resolve with hyperpigmentation and atrophy; Subcutaneous fat loss on face with resultant sunken eyes, aged appearance

Craniofacial/Body Habitus
Cachectic dwarf with microcephaly, thin nose, large ears ("Mickey Mouse" appear
ance); disproportionately long limbs with joint contractures; large, cold hands and feet
Clinical
Nervous System
Diffuse clemyelination of the (CNS) and peripheral nerves
with progressive neurologic deterioration; mental retardation; intracranial calcifications

Ear Nose Throat
Sensorineural deafness

Eyes:
"Salt and pepper" retinal pigment, miotic pupils may be difficult to dilate, cataracts, optic atrophy

Teeth
Dental caries
DDx
Bloom syndrome (p. 234)
Roth m u nd Thomson syndrome (p. 238)
Hartnup syndrome (p. 250)
XP (p. 174)
Progeria (p. 156)
Lab
DNA analysis

Blood serum UV irradiated cells with decreased DNA, RNA synthesis

Brain computed tomography (CT) calcifications; cortical atrophy
Management
Photoprotection with sunscreens, clothing, avoidance of sun
Referral to neurologist, ophthalmologist, ear nose throat (ENT) specialist, dentist
Prognosis
Progressive, unremitting neurologic degeneration with death by second to third decade