Case of the Week
Section Editors: Matylda Machnowska1 and Anvita Pauranik2
1University of Toronto, Toronto, Ontario, Canada
2BC Children's Hospital, University of British Columbia, Vancouver, British Columbia, Canada
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September 8, 2016
Cockayne Syndrome
- Background:
- Rare autosomal recessive disorder with defective DNA repair mechanism
- Clinical Presentation:
- Type I: Most common, characterized by normal prenatal growth and development followed by the onset of severe growth retardation and neurodegeneration in the first few years of life
- Type II: Severe form where growth retardation is present at birth.
- Type III: Late-onset variety characterized by normal growth and maintained cognition with late onset of symptoms and is the rarest form
- Photosensitive rashes and cataracts
- Key Diagnostic Features:
- Intracranial calcifications are seen in nearly all patients beyond 3 years of age, specifically:
- Dense basal ganglia calcifications especially involving the putamina
- Cortical calcifications more commonly seen in the severe form (type II)
- Dentate nucleus and leptomeningeal vessel calcification may also be present
- Calvarial thickening is one of the minor criteria for diagnosis of classical Cockaynes syndrome.
- Cerebral atrophy with parietooccipital predominance; cerebellar atrophy may also be present.
- White matter signal abnormalities presenting as T2 and FLAIR hyperintensity are seen, involving the white matter and attributed variously to demyelination and hypomyelination. Cerebellar and brain stem myelination is preserved in these patients.
- The constellation of findings, including dense basal ganglia and dentate nucleus calcifications, white matter signal abnormalities, and cerebral atrophy, is typical of Cockayne syndrome.
- Intracranial calcifications are seen in nearly all patients beyond 3 years of age, specifically:
- Differential Diagnoses:
- Pelizaeus-Merzbacher disease (no intracranial calcifications)
- Aicardi-Goutieres syndrome (punctate and small basal ganglia calcifications)
- Cytomegalovirus infection (periventricular and cortical malformation)
- Mitochondrial diseases (more severe white matter loss in Cockayne syndrome)
- Treatment:
- There is no permanent cure. Supportive measures in the form of physical therapy, maintenance of optimal nutrition, use of sunscreens and avoidance of sun exposure are required. The prognosis is poor. Genetic counselling of the parents is recommended.