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12 Cards in this Set
- Front
- Back
Clinical Cockayne Syndrome
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Inheritance
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Autosomal recessive; Cockayne syndrome group A (CSA): ERCC8 gene on chromosome 5
Cockayne syndrome group B (CSB): ERCC6 gene on 10q11 |
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prenatal
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Amniocentesis/amniotic fluid cell culture deficient RNA synthesis and increased c death after UV irradiation
DNA analysis |
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Incidence
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Very rare; M=F;
CSB most common (80% of cases) |
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Age at Presentation
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Birth to 2 years old; some later, into teens
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Pathogenesis
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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 |
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Clinical
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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 |
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Clinical
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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 |
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DDx
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Bloom syndrome (p. 234)
Roth m u nd Thomson syndrome (p. 238) Hartnup syndrome (p. 250) XP (p. 174) Progeria (p. 156) |
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Lab
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DNA analysis
Blood serum UV irradiated cells with decreased DNA, RNA synthesis Brain computed tomography (CT) calcifications; cortical atrophy |
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Management
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Photoprotection with sunscreens, clothing, avoidance of sun
Referral to neurologist, ophthalmologist, ear nose throat (ENT) specialist, dentist |
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Prognosis
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Progressive, unremitting neurologic degeneration with death by second to third decade
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